diff --git a/apps/vr-tests-react-components/src/stories/Input.stories.tsx b/apps/vr-tests-react-components/src/stories/Input.stories.tsx
index d3233f1b528209..ad5bec6335ff11 100644
--- a/apps/vr-tests-react-components/src/stories/Input.stories.tsx
+++ b/apps/vr-tests-react-components/src/stories/Input.stories.tsx
@@ -4,6 +4,7 @@ import { storiesOf } from '@storybook/react';
 import { Input } from '@fluentui/react-input';
 import { SearchRegular, DismissRegular } from '@fluentui/react-icons';
 import { TestWrapperDecoratorFixedWidth } from '../utilities/TestWrapperDecorator';
+import { FluentProvider } from '@fluentui/react-provider';
 
 storiesOf('Input Converged', module)
   .addDecorator(TestWrapperDecoratorFixedWidth)
@@ -65,4 +66,12 @@ storiesOf('Input Converged', module)
     'contentAfter',
     () => <Input contentAfter={<DismissRegular style={{ fontSize: '20px' }} />} placeholder="Placeholder" />,
     { includeRtl: true },
-  );
+  )
+  .addStory('With appearance override', () => (
+    <FluentProvider overrides_unstable={{ inputDefaultAppearance: 'filled-darker' }}>
+      <div style={{ display: 'flex', flexDirection: 'column', gap: '10px' }}>
+        <Input placeholder="Default overriden appearance" />
+        <Input appearance="outline" placeholder="Outline appearance" />
+      </div>
+    </FluentProvider>
+  ));
diff --git a/apps/vr-tests-react-components/src/stories/Select.stories.tsx b/apps/vr-tests-react-components/src/stories/Select.stories.tsx
index cdb5e7266b3b21..fd53a7013f0d43 100644
--- a/apps/vr-tests-react-components/src/stories/Select.stories.tsx
+++ b/apps/vr-tests-react-components/src/stories/Select.stories.tsx
@@ -3,6 +3,7 @@ import { Steps, StoryWright } from 'storywright';
 import { storiesOf } from '@storybook/react';
 import { Select } from '@fluentui/react-select';
 import { TestWrapperDecoratorFixedWidth } from '../utilities/TestWrapperDecorator';
+import { FluentProvider } from '@fluentui/react-provider';
 
 storiesOf('Select Converged', module)
   .addDecorator(TestWrapperDecoratorFixedWidth)
@@ -102,4 +103,16 @@ storiesOf('Select Converged', module)
     <Select icon="+">
       <option>text</option>
     </Select>
+  ))
+  .addStory('With appearance override', () => (
+    <FluentProvider overrides_unstable={{ inputDefaultAppearance: 'filled-darker' }}>
+      <div style={{ display: 'flex', flexDirection: 'column', gap: '10px' }}>
+        <Select>
+          <option>Default overriden appearance</option>
+        </Select>
+        <Select appearance="outline">
+          <option>Outline appearance</option>
+        </Select>
+      </div>
+    </FluentProvider>
   ));
diff --git a/apps/vr-tests-react-components/src/stories/SpinButton.stories.tsx b/apps/vr-tests-react-components/src/stories/SpinButton.stories.tsx
index 554e9b3dab3c6b..d911ba558dbc30 100644
--- a/apps/vr-tests-react-components/src/stories/SpinButton.stories.tsx
+++ b/apps/vr-tests-react-components/src/stories/SpinButton.stories.tsx
@@ -3,6 +3,7 @@ import { Steps, StoryWright } from 'storywright';
 import { storiesOf } from '@storybook/react';
 import { SpinButton, spinButtonClassNames } from '@fluentui/react-spinbutton';
 import { TestWrapperDecoratorFixedWidth } from '../utilities/TestWrapperDecorator';
+import { FluentProvider } from '@fluentui/react-provider';
 
 const cropTo = '.testWrapper';
 
@@ -172,4 +173,12 @@ storiesOf('SpinButton Converged', module)
     includeHighContrast: true,
     includeDarkMode: true,
   })
-  .addStory('Size: medium (default)', () => <SpinButton value={10} />, { includeRtl: true });
+  .addStory('Size: medium (default)', () => <SpinButton value={10} />, { includeRtl: true })
+  .addStory('With appearance override', () => (
+    <FluentProvider overrides_unstable={{ inputDefaultAppearance: 'filled-darker' }}>
+      <div style={{ display: 'flex', flexDirection: 'column', gap: '10px' }}>
+        <SpinButton value={10} />
+        <SpinButton value={10} appearance="outline" />
+      </div>
+    </FluentProvider>
+  ));
diff --git a/apps/vr-tests-react-components/src/stories/Textarea.stories.tsx b/apps/vr-tests-react-components/src/stories/Textarea.stories.tsx
index d5dbef6f5cdae1..bdb63be8204ba1 100644
--- a/apps/vr-tests-react-components/src/stories/Textarea.stories.tsx
+++ b/apps/vr-tests-react-components/src/stories/Textarea.stories.tsx
@@ -3,6 +3,7 @@ import { Steps, StoryWright } from 'storywright';
 import { storiesOf } from '@storybook/react';
 import { Textarea } from '@fluentui/react-textarea';
 import { TestWrapperDecoratorFixedWidth } from '../utilities/TestWrapperDecorator';
+import { FluentProvider } from '@fluentui/react-provider';
 
 storiesOf('Textarea Converged', module)
   .addDecorator(TestWrapperDecoratorFixedWidth)
@@ -47,4 +48,12 @@ storiesOf('Textarea Converged', module)
   ))
   .addStory('Size: small', () => <Textarea size="small" placeholder="Placeholder" />)
   .addStory('Size: medium', () => <Textarea size="medium" placeholder="Placeholder" />)
-  .addStory('Size: large', () => <Textarea size="large" placeholder="Placeholder" />);
+  .addStory('Size: large', () => <Textarea size="large" placeholder="Placeholder" />)
+  .addStory('With appearance override', () => (
+    <FluentProvider overrides_unstable={{ inputDefaultAppearance: 'filled-darker' }}>
+      <div style={{ display: 'flex', flexDirection: 'column', gap: '10px' }}>
+        <Textarea placeholder="Default overriden appearance" />
+        <Textarea appearance="outline" placeholder="Outline appearance" />
+      </div>
+    </FluentProvider>
+  ));
diff --git a/change/@fluentui-react-components-a0044760-9cac-456d-b748-7fe4ba0802ae.json b/change/@fluentui-react-components-a0044760-9cac-456d-b748-7fe4ba0802ae.json
new file mode 100644
index 00000000000000..7beb141428f102
--- /dev/null
+++ b/change/@fluentui-react-components-a0044760-9cac-456d-b748-7fe4ba0802ae.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: add support for appearance overrides (unstable)",
+  "packageName": "@fluentui/react-components",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/@fluentui-react-context-selector-e15ee4a6-fa19-42f0-9f11-f84a14a57ab9.json b/change/@fluentui-react-context-selector-e15ee4a6-fa19-42f0-9f11-f84a14a57ab9.json
new file mode 100644
index 00000000000000..c2b603b30677a1
--- /dev/null
+++ b/change/@fluentui-react-context-selector-e15ee4a6-fa19-42f0-9f11-f84a14a57ab9.json
@@ -0,0 +1,7 @@
+{
+  "type": "none",
+  "comment": "chore: fix a typo in jsdoc",
+  "packageName": "@fluentui/react-context-selector",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "none"
+}
diff --git a/change/@fluentui-react-input-c8b8ede9-cfd9-47de-8c13-eca4f6c72797.json b/change/@fluentui-react-input-c8b8ede9-cfd9-47de-8c13-eca4f6c72797.json
new file mode 100644
index 00000000000000..61ee37da523edc
--- /dev/null
+++ b/change/@fluentui-react-input-c8b8ede9-cfd9-47de-8c13-eca4f6c72797.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: Allow default appearance override",
+  "packageName": "@fluentui/react-input",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/@fluentui-react-portal-1d522e45-92ff-4aaa-8f80-0d6aa88b3fd8.json b/change/@fluentui-react-portal-1d522e45-92ff-4aaa-8f80-0d6aa88b3fd8.json
new file mode 100644
index 00000000000000..dab35641c7dd3e
--- /dev/null
+++ b/change/@fluentui-react-portal-1d522e45-92ff-4aaa-8f80-0d6aa88b3fd8.json
@@ -0,0 +1,7 @@
+{
+  "type": "none",
+  "comment": "Lint based re-format",
+  "packageName": "@fluentui/react-portal",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "none"
+}
diff --git a/change/@fluentui-react-provider-ea932e89-e206-4ea6-81dc-ba918be05393.json b/change/@fluentui-react-provider-ea932e89-e206-4ea6-81dc-ba918be05393.json
new file mode 100644
index 00000000000000..ae998f06464375
--- /dev/null
+++ b/change/@fluentui-react-provider-ea932e89-e206-4ea6-81dc-ba918be05393.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: add support for overrides (unstable)",
+  "packageName": "@fluentui/react-provider",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/@fluentui-react-select-9227eb92-f238-441d-9a44-e311026f50e5.json b/change/@fluentui-react-select-9227eb92-f238-441d-9a44-e311026f50e5.json
new file mode 100644
index 00000000000000..985b734ab72753
--- /dev/null
+++ b/change/@fluentui-react-select-9227eb92-f238-441d-9a44-e311026f50e5.json
@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "feat: Allow default appearance override",
+  "packageName": "@fluentui/react-select",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/@fluentui-react-shared-contexts-cf45a4fd-ebcd-4623-8d35-ee8813910004.json b/change/@fluentui-react-shared-contexts-cf45a4fd-ebcd-4623-8d35-ee8813910004.json
new file mode 100644
index 00000000000000..ed13b4a92ac933
--- /dev/null
+++ b/change/@fluentui-react-shared-contexts-cf45a4fd-ebcd-4623-8d35-ee8813910004.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: Overrides context",
+  "packageName": "@fluentui/react-shared-contexts",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/@fluentui-react-spinbutton-c02b94ea-c41f-49cf-8024-e513da3c3a3d.json b/change/@fluentui-react-spinbutton-c02b94ea-c41f-49cf-8024-e513da3c3a3d.json
new file mode 100644
index 00000000000000..5ad97980d5a356
--- /dev/null
+++ b/change/@fluentui-react-spinbutton-c02b94ea-c41f-49cf-8024-e513da3c3a3d.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: Allow default appearance override",
+  "packageName": "@fluentui/react-spinbutton",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/change/@fluentui-react-textarea-a7574993-8632-461c-8f9b-51df664a3dc8.json b/change/@fluentui-react-textarea-a7574993-8632-461c-8f9b-51df664a3dc8.json
new file mode 100644
index 00000000000000..83cf219a3ed55c
--- /dev/null
+++ b/change/@fluentui-react-textarea-a7574993-8632-461c-8f9b-51df664a3dc8.json
@@ -0,0 +1,7 @@
+{
+  "type": "minor",
+  "comment": "feat: Allow default appearance override",
+  "packageName": "@fluentui/react-textarea",
+  "email": "miroslav.stastny@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/packages/fluentui/react-northstar-fela-renderer/src/createFelaRenderer.tsx b/packages/fluentui/react-northstar-fela-renderer/src/createFelaRenderer.tsx
index 6ce78ea753af3b..5c580117283e63 100644
--- a/packages/fluentui/react-northstar-fela-renderer/src/createFelaRenderer.tsx
+++ b/packages/fluentui/react-northstar-fela-renderer/src/createFelaRenderer.tsx
@@ -23,7 +23,7 @@ try {
   felaDevMode = !!window.localStorage.felaDevMode;
 } catch {}
 
-if (typeof window !== "undefined" && process.env.NODE_ENV !== 'production' && process.env.NODE_ENV !== 'test') {
+if (typeof window !== 'undefined' && process.env.NODE_ENV !== 'production' && process.env.NODE_ENV !== 'test') {
   if (felaDevMode) {
     /* eslint-disable-next-line no-console */
     console.warn(
diff --git a/packages/react-components/react-context-selector/src/useContextSelector.ts b/packages/react-components/react-context-selector/src/useContextSelector.ts
index 4c2dea929d457c..32b81e54268c59 100644
--- a/packages/react-components/react-context-selector/src/useContextSelector.ts
+++ b/packages/react-components/react-context-selector/src/useContextSelector.ts
@@ -16,7 +16,7 @@ type ContextReducer<Value, SelectedValue> = React.Reducer<
  * @internal
  * This hook returns context selected value by selector.
  * It will only accept context created by `createContext`.
- * It will trigger re-render if only the selected value is referencially changed.
+ * It will trigger re-render if only the selected value is referentially changed.
  */
 export const useContextSelector = <Value, SelectedValue>(
   context: Context<Value>,
diff --git a/packages/react-components/react-input/package.json b/packages/react-components/react-input/package.json
index 08616e97921817..f68aa2ea754717 100644
--- a/packages/react-components/react-input/package.json
+++ b/packages/react-components/react-input/package.json
@@ -34,6 +34,7 @@
   },
   "dependencies": {
     "@fluentui/react-field": "9.0.0-alpha.16",
+    "@fluentui/react-shared-contexts": "^9.1.5",
     "@fluentui/react-theme": "^9.1.5",
     "@fluentui/react-utilities": "^9.4.0",
     "@griffel/react": "^1.5.2",
diff --git a/packages/react-components/react-input/src/components/Input/useInput.ts b/packages/react-components/react-input/src/components/Input/useInput.ts
index e13bbcd0368d12..5ac182f22f29e9 100644
--- a/packages/react-components/react-input/src/components/Input/useInput.ts
+++ b/packages/react-components/react-input/src/components/Input/useInput.ts
@@ -6,6 +6,7 @@ import {
   useEventCallback,
 } from '@fluentui/react-utilities';
 import type { InputProps, InputState } from './Input.types';
+import { useOverrides_unstable as useOverrides } from '@fluentui/react-shared-contexts';
 
 /**
  * Create the state required to render Input.
@@ -17,7 +18,9 @@ import type { InputProps, InputState } from './Input.types';
  * @param ref - reference to `<input>` element of Input
  */
 export const useInput_unstable = (props: InputProps, ref: React.Ref<HTMLInputElement>): InputState => {
-  const { size = 'medium', appearance = 'outline', onChange } = props;
+  const overrides = useOverrides();
+
+  const { size = 'medium', appearance = overrides.inputDefaultAppearance ?? 'outline', onChange } = props;
 
   if (
     process.env.NODE_ENV !== 'production' &&
diff --git a/packages/react-components/react-portal/src/components/Portal/usePortal.ts b/packages/react-components/react-portal/src/components/Portal/usePortal.ts
index dc69fccc93d031..cb1c0943918881 100644
--- a/packages/react-components/react-portal/src/components/Portal/usePortal.ts
+++ b/packages/react-components/react-portal/src/components/Portal/usePortal.ts
@@ -27,7 +27,9 @@ export const usePortal_unstable = (props: PortalProps): PortalState => {
       setVirtualParent(state.mountNode, state.virtualParentRootRef.current);
     }
     return () => {
-      if (state.mountNode) {setVirtualParent(state.mountNode, undefined);}
+      if (state.mountNode) {
+        setVirtualParent(state.mountNode, undefined);
+      }
     };
   }, [state.virtualParentRootRef, state.mountNode]);
 
diff --git a/packages/react-components/react-provider/etc/react-provider.api.md b/packages/react-components/react-provider/etc/react-provider.api.md
index b00b71cd2cdd68..68501a5f40d823 100644
--- a/packages/react-components/react-provider/etc/react-provider.api.md
+++ b/packages/react-components/react-provider/etc/react-provider.api.md
@@ -6,6 +6,7 @@
 
 import { ComponentProps } from '@fluentui/react-utilities';
 import type { ComponentState } from '@fluentui/react-utilities';
+import { OverridesContextValue_unstable } from '@fluentui/react-shared-contexts';
 import type { PartialTheme } from '@fluentui/react-theme';
 import type { ProviderContextValue_unstable } from '@fluentui/react-shared-contexts';
 import * as React_2 from 'react';
@@ -22,13 +23,14 @@ export const FluentProvider: React_2.ForwardRefExoticComponent<Omit<ComponentPro
     dir?: "ltr" | "rtl" | undefined;
     targetDocument?: Document | undefined;
     theme?: Partial<Theme> | undefined;
+    overrides_unstable?: OverridesContextValue_unstable | undefined;
 } & React_2.RefAttributes<HTMLElement>>;
 
 // @public (undocumented)
 export const fluentProviderClassNames: SlotClassNames<FluentProviderSlots>;
 
 // @public (undocumented)
-export type FluentProviderContextValues = Pick<FluentProviderState, 'theme'> & {
+export type FluentProviderContextValues = Pick<FluentProviderState, 'theme' | 'overrides_unstable'> & {
     provider: ProviderContextValue_unstable;
     themeClassName: ThemeClassNameContextValue_unstable;
     textDirection: 'ltr' | 'rtl';
@@ -41,6 +43,7 @@ export type FluentProviderProps = Omit<ComponentProps<FluentProviderSlots>, 'dir
     dir?: 'ltr' | 'rtl';
     targetDocument?: Document;
     theme?: PartialTheme;
+    overrides_unstable?: OverridesContextValue_unstable;
 };
 
 // @public (undocumented)
@@ -49,7 +52,7 @@ export type FluentProviderSlots = {
 };
 
 // @public (undocumented)
-export type FluentProviderState = ComponentState<FluentProviderSlots> & Pick<FluentProviderProps, 'targetDocument'> & Required<Pick<FluentProviderProps, 'applyStylesToPortals' | 'dir'>> & {
+export type FluentProviderState = ComponentState<FluentProviderSlots> & Pick<FluentProviderProps, 'targetDocument'> & Required<Pick<FluentProviderProps, 'applyStylesToPortals' | 'dir' | 'overrides_unstable'>> & {
     theme: ThemeContextValue_unstable;
     themeClassName: string;
 };
diff --git a/packages/react-components/react-provider/src/components/FluentProvider/FluentProvider.types.ts b/packages/react-components/react-provider/src/components/FluentProvider/FluentProvider.types.ts
index de048f9c1cff1e..ab2655900c3583 100644
--- a/packages/react-components/react-provider/src/components/FluentProvider/FluentProvider.types.ts
+++ b/packages/react-components/react-provider/src/components/FluentProvider/FluentProvider.types.ts
@@ -1,4 +1,5 @@
 import type {
+  OverridesContextValue_unstable as OverridesContextValue,
   ProviderContextValue_unstable as ProviderContextValue,
   TooltipVisibilityContextValue_unstable as TooltipVisibilityContextValue,
   ThemeClassNameContextValue_unstable as ThemeClassNameContextValue,
@@ -26,16 +27,19 @@ export type FluentProviderProps = Omit<ComponentProps<FluentProviderSlots>, 'dir
 
   /** Sets the theme used in a scope. */
   theme?: PartialTheme;
+
+  // eslint-disable-next-line @typescript-eslint/naming-convention
+  overrides_unstable?: OverridesContextValue;
 };
 
 export type FluentProviderState = ComponentState<FluentProviderSlots> &
   Pick<FluentProviderProps, 'targetDocument'> &
-  Required<Pick<FluentProviderProps, 'applyStylesToPortals' | 'dir'>> & {
+  Required<Pick<FluentProviderProps, 'applyStylesToPortals' | 'dir' | 'overrides_unstable'>> & {
     theme: ThemeContextValue;
     themeClassName: string;
   };
 
-export type FluentProviderContextValues = Pick<FluentProviderState, 'theme'> & {
+export type FluentProviderContextValues = Pick<FluentProviderState, 'theme' | 'overrides_unstable'> & {
   provider: ProviderContextValue;
   themeClassName: ThemeClassNameContextValue;
   textDirection: 'ltr' | 'rtl';
diff --git a/packages/react-components/react-provider/src/components/FluentProvider/renderFluentProvider.tsx b/packages/react-components/react-provider/src/components/FluentProvider/renderFluentProvider.tsx
index f7e2551a52a827..f902592c381c74 100644
--- a/packages/react-components/react-provider/src/components/FluentProvider/renderFluentProvider.tsx
+++ b/packages/react-components/react-provider/src/components/FluentProvider/renderFluentProvider.tsx
@@ -1,6 +1,7 @@
 import * as React from 'react';
 import { TextDirectionProvider } from '@griffel/react';
 import {
+  OverridesProvider_unstable as OverridesProvider,
   Provider_unstable as Provider,
   TooltipVisibilityProvider_unstable as TooltipVisibilityProvider,
   ThemeProvider_unstable as ThemeProvider,
@@ -24,7 +25,9 @@ export const renderFluentProvider_unstable = (
         <ThemeClassNameProvider value={contextValues.themeClassName}>
           <TooltipVisibilityProvider value={contextValues.tooltip}>
             <TextDirectionProvider dir={contextValues.textDirection}>
-              <slots.root {...slotProps.root}>{state.root.children}</slots.root>
+              <OverridesProvider value={contextValues.overrides_unstable}>
+                <slots.root {...slotProps.root}>{state.root.children}</slots.root>
+              </OverridesProvider>
             </TextDirectionProvider>
           </TooltipVisibilityProvider>
         </ThemeClassNameProvider>
diff --git a/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.test.tsx b/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.test.tsx
index a771b71fd61612..0a3f067616c94a 100644
--- a/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.test.tsx
+++ b/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.test.tsx
@@ -4,6 +4,7 @@ import * as React from 'react';
 import { FluentProvider } from './FluentProvider';
 import { useFluentProvider_unstable } from './useFluentProvider';
 import type { PartialTheme } from '@fluentui/react-theme';
+import { OverridesContextValue_unstable } from '@fluentui/react-shared-contexts';
 
 describe('useFluentProvider_unstable', () => {
   // eslint-disable-next-line @typescript-eslint/no-empty-function
@@ -50,4 +51,34 @@ describe('useFluentProvider_unstable', () => {
       }
     `);
   });
+
+  it('should merge overrides', () => {
+    const overridesA: OverridesContextValue_unstable = {
+      inputDefaultAppearance: 'filled-lighter',
+      // currently the overrides object contains a single value, adding one more to test the merging
+      customValue: 'shouldNotBeOverridden',
+    } as OverridesContextValue_unstable;
+    const overridesB: OverridesContextValue_unstable = {
+      inputDefaultAppearance: 'filled-darker',
+    };
+
+    const Wrapper: React.FC = ({ children }) => (
+      <FluentProvider overrides_unstable={overridesA}>{children}</FluentProvider>
+    );
+
+    const { result } = renderHook(
+      // eslint-disable-next-line @typescript-eslint/naming-convention
+      () => useFluentProvider_unstable({ overrides_unstable: overridesB }, React.createRef()),
+      {
+        wrapper: Wrapper,
+      },
+    );
+
+    expect(result.current.overrides_unstable).toMatchInlineSnapshot(`
+      Object {
+        "customValue": "shouldNotBeOverridden",
+        "inputDefaultAppearance": "filled-darker",
+      }
+    `);
+  });
 });
diff --git a/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.ts b/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.ts
index ef89b1f140fd84..87412611aeb15e 100644
--- a/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.ts
+++ b/packages/react-components/react-provider/src/components/FluentProvider/useFluentProvider.ts
@@ -2,6 +2,7 @@ import { useFocusVisible } from '@fluentui/react-tabster';
 import {
   ThemeContext_unstable as ThemeContext,
   useFluent_unstable as useFluent,
+  useOverrides_unstable as useOverrides,
 } from '@fluentui/react-shared-contexts';
 import type { ThemeContextValue_unstable as ThemeContextValue } from '@fluentui/react-shared-contexts';
 import { getNativeElementProps, useMergedRefs } from '@fluentui/react-utilities';
@@ -24,6 +25,7 @@ export const useFluentProvider_unstable = (
 ): FluentProviderState => {
   const parentContext = useFluent();
   const parentTheme = useTheme();
+  const parentOverrides = useOverrides();
 
   /**
    * TODO: add merge functions to "dir" merge,
@@ -35,8 +37,11 @@ export const useFluentProvider_unstable = (
     dir = parentContext.dir,
     targetDocument = parentContext.targetDocument,
     theme,
+    overrides_unstable: overrides = {},
   } = props;
-  const mergedTheme = mergeThemes(parentTheme, theme);
+  const mergedTheme = shallowMerge(parentTheme, theme);
+
+  const mergedOverrides = shallowMerge(parentOverrides, overrides);
 
   React.useEffect(() => {
     if (process.env.NODE_ENV !== 'production' && mergedTheme === undefined) {
@@ -55,6 +60,8 @@ export const useFluentProvider_unstable = (
     dir,
     targetDocument,
     theme: mergedTheme,
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    overrides_unstable: mergedOverrides,
     themeClassName: useFluentProviderThemeStyleTag({ theme: mergedTheme, targetDocument }),
 
     components: {
@@ -69,7 +76,7 @@ export const useFluentProvider_unstable = (
   };
 };
 
-function mergeThemes(a: ThemeContextValue, b: ThemeContextValue): ThemeContextValue {
+function shallowMerge<T>(a: T, b: T): T {
   // Merge impacts perf: we should like to avoid it if it's possible
   if (a && b) {
     return { ...a, ...b };
diff --git a/packages/react-components/react-provider/src/components/FluentProvider/useFluentProviderContextValues.ts b/packages/react-components/react-provider/src/components/FluentProvider/useFluentProviderContextValues.ts
index 73c575c9ea498d..528a60722ef99c 100644
--- a/packages/react-components/react-provider/src/components/FluentProvider/useFluentProviderContextValues.ts
+++ b/packages/react-components/react-provider/src/components/FluentProvider/useFluentProviderContextValues.ts
@@ -2,13 +2,16 @@ import * as React from 'react';
 import type { FluentProviderContextValues, FluentProviderState } from './FluentProvider.types';
 
 export function useFluentProviderContextValues_unstable(state: FluentProviderState): FluentProviderContextValues {
-  const { applyStylesToPortals, dir, root, targetDocument, theme, themeClassName } = state;
+  // eslint-disable-next-line @typescript-eslint/naming-convention
+  const { applyStylesToPortals, dir, root, targetDocument, theme, themeClassName, overrides_unstable } = state;
 
   const provider = React.useMemo(() => ({ dir, targetDocument }), [dir, targetDocument]);
   // "Tooltip" component mutates an object in this context, instance should be stable
   const [tooltip] = React.useState(() => ({}));
 
   return {
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    overrides_unstable,
     provider,
     textDirection: dir,
     tooltip,
diff --git a/packages/react-components/react-select/package.json b/packages/react-components/react-select/package.json
index 32560c88215a42..f4c6028ddc6004 100644
--- a/packages/react-components/react-select/package.json
+++ b/packages/react-components/react-select/package.json
@@ -34,6 +34,7 @@
   "dependencies": {
     "@fluentui/react-field": "9.0.0-alpha.16",
     "@fluentui/react-icons": "^2.0.175",
+    "@fluentui/react-shared-contexts": "^9.1.5",
     "@fluentui/react-theme": "^9.1.5",
     "@fluentui/react-utilities": "^9.4.0",
     "@griffel/react": "^1.5.2",
diff --git a/packages/react-components/react-select/src/components/Select/useSelect.tsx b/packages/react-components/react-select/src/components/Select/useSelect.tsx
index 48374e94d8d634..7146c080ffcb86 100644
--- a/packages/react-components/react-select/src/components/Select/useSelect.tsx
+++ b/packages/react-components/react-select/src/components/Select/useSelect.tsx
@@ -2,6 +2,7 @@ import * as React from 'react';
 import { getPartitionedNativeProps, resolveShorthand, useEventCallback } from '@fluentui/react-utilities';
 import { ChevronDownRegular } from '@fluentui/react-icons';
 import type { SelectProps, SelectState } from './Select.types';
+import { useOverrides_unstable as useOverrides } from '@fluentui/react-shared-contexts';
 
 /**
  * Create the state required to render Select.
@@ -13,13 +14,15 @@ import type { SelectProps, SelectState } from './Select.types';
  * @param ref - reference to the `<select>` element in Select
  */
 export const useSelect_unstable = (props: SelectProps, ref: React.Ref<HTMLSelectElement>): SelectState => {
+  const overrides = useOverrides();
+
   const {
     defaultValue,
     value,
     select,
     icon,
     root,
-    appearance = 'outline',
+    appearance = overrides.inputDefaultAppearance ?? 'outline',
 
     onChange,
     size = 'medium',
diff --git a/packages/react-components/react-shared-contexts/etc/react-shared-contexts.api.md b/packages/react-components/react-shared-contexts/etc/react-shared-contexts.api.md
index 215ca76c963948..1df0905d957c17 100644
--- a/packages/react-components/react-shared-contexts/etc/react-shared-contexts.api.md
+++ b/packages/react-components/react-shared-contexts/etc/react-shared-contexts.api.md
@@ -7,6 +7,14 @@
 import * as React_2 from 'react';
 import type { Theme } from '@fluentui/react-theme';
 
+// @internal (undocumented)
+export type OverridesContextValue_unstable = {
+    inputDefaultAppearance?: 'outline' | 'filled-darker' | 'filled-lighter';
+};
+
+// @internal (undocumented)
+export const OverridesProvider_unstable: React_2.Provider<OverridesContextValue_unstable | undefined>;
+
 // @internal (undocumented)
 export const Provider_unstable: React_2.Provider<ProviderContextValue_unstable>;
 
@@ -44,6 +52,11 @@ export const TooltipVisibilityProvider_unstable: React_2.Provider<TooltipVisibil
 // @public (undocumented)
 export function useFluent_unstable(): ProviderContextValue_unstable;
 
+// Warning: (ae-incompatible-release-tags) The symbol "useOverrides" is marked as @public, but its signature references "OverridesContextValue" which is marked as @internal
+//
+// @public (undocumented)
+export function useOverrides_unstable(): OverridesContextValue_unstable;
+
 // @public (undocumented)
 export function useThemeClassName_unstable(): ThemeClassNameContextValue_unstable;
 
diff --git a/packages/react-components/react-shared-contexts/src/OverridesContext/OverridesContext.ts b/packages/react-components/react-shared-contexts/src/OverridesContext/OverridesContext.ts
new file mode 100644
index 00000000000000..10da445b61a663
--- /dev/null
+++ b/packages/react-components/react-shared-contexts/src/OverridesContext/OverridesContext.ts
@@ -0,0 +1,23 @@
+import * as React from 'react';
+
+/**
+ * @internal
+ */
+export type OverridesContextValue = {
+  // No 'underline' as it is not supported by TextArea
+  inputDefaultAppearance?: 'outline' | 'filled-darker' | 'filled-lighter';
+};
+
+/**
+ * @internal
+ */
+export const OverridesContext = React.createContext<OverridesContextValue | undefined>(undefined);
+
+/**
+ * @internal
+ */
+export const OverridesProvider = OverridesContext.Provider;
+
+export function useOverrides(): OverridesContextValue {
+  return React.useContext(OverridesContext) ?? {};
+}
diff --git a/packages/react-components/react-shared-contexts/src/OverridesContext/index.ts b/packages/react-components/react-shared-contexts/src/OverridesContext/index.ts
new file mode 100644
index 00000000000000..43b32e1e274296
--- /dev/null
+++ b/packages/react-components/react-shared-contexts/src/OverridesContext/index.ts
@@ -0,0 +1 @@
+export * from './OverridesContext';
diff --git a/packages/react-components/react-shared-contexts/src/index.ts b/packages/react-components/react-shared-contexts/src/index.ts
index b56d6505192f34..61c45c7f2e0f4b 100644
--- a/packages/react-components/react-shared-contexts/src/index.ts
+++ b/packages/react-components/react-shared-contexts/src/index.ts
@@ -15,3 +15,9 @@ export type { TooltipVisibilityContextValue as TooltipVisibilityContextValue_uns
 
 export { Provider as Provider_unstable, useFluent as useFluent_unstable } from './ProviderContext';
 export type { ProviderContextValue as ProviderContextValue_unstable } from './ProviderContext';
+
+export {
+  OverridesProvider as OverridesProvider_unstable,
+  useOverrides as useOverrides_unstable,
+} from './OverridesContext';
+export type { OverridesContextValue as OverridesContextValue_unstable } from './OverridesContext';
diff --git a/packages/react-components/react-spinbutton/package.json b/packages/react-components/react-spinbutton/package.json
index 45deaa74a180cd..f389f458df5c6c 100644
--- a/packages/react-components/react-spinbutton/package.json
+++ b/packages/react-components/react-spinbutton/package.json
@@ -38,6 +38,7 @@
     "@fluentui/react-field": "9.0.0-alpha.16",
     "@fluentui/react-icons": "^2.0.175",
     "@fluentui/react-input": "^9.2.13",
+    "@fluentui/react-shared-contexts": "^9.1.5",
     "@fluentui/react-theme": "^9.1.5",
     "@fluentui/react-utilities": "^9.4.0",
     "tslib": "^2.1.0"
diff --git a/packages/react-components/react-spinbutton/src/components/SpinButton/useSpinButton.tsx b/packages/react-components/react-spinbutton/src/components/SpinButton/useSpinButton.tsx
index e8d08b8b119e36..425ed2e690ad91 100644
--- a/packages/react-components/react-spinbutton/src/components/SpinButton/useSpinButton.tsx
+++ b/packages/react-components/react-spinbutton/src/components/SpinButton/useSpinButton.tsx
@@ -16,6 +16,7 @@ import {
 } from './SpinButton.types';
 import { calculatePrecision, precisionRound, getBound, clamp } from '../../utils/index';
 import { ChevronUp16Regular, ChevronDown16Regular } from '@fluentui/react-icons';
+import { useOverrides_unstable as useOverrides } from '@fluentui/react-shared-contexts';
 
 type InternalState = {
   value: number | null;
@@ -51,6 +52,8 @@ export const useSpinButton_unstable = (props: SpinButtonProps, ref: React.Ref<HT
     excludedPropNames: ['defaultValue', 'max', 'min', 'onChange', 'size', 'value'],
   });
 
+  const overrides = useOverrides();
+
   const {
     value,
     displayValue,
@@ -62,7 +65,7 @@ export const useSpinButton_unstable = (props: SpinButtonProps, ref: React.Ref<HT
     precision: precisionFromProps,
     onChange,
     size = 'medium',
-    appearance = 'outline',
+    appearance = overrides.inputDefaultAppearance ?? 'outline',
     root,
     input,
     incrementButton,
diff --git a/packages/react-components/react-textarea/package.json b/packages/react-components/react-textarea/package.json
index 470be2137da0f0..eb2b41867aaf36 100644
--- a/packages/react-components/react-textarea/package.json
+++ b/packages/react-components/react-textarea/package.json
@@ -33,6 +33,7 @@
   },
   "dependencies": {
     "@fluentui/react-field": "9.0.0-alpha.16",
+    "@fluentui/react-shared-contexts": "^9.1.5",
     "@fluentui/react-theme": "^9.1.5",
     "@fluentui/react-utilities": "^9.4.0",
     "@griffel/react": "^1.5.2",
diff --git a/packages/react-components/react-textarea/src/components/Textarea/useTextarea.ts b/packages/react-components/react-textarea/src/components/Textarea/useTextarea.ts
index 6f012a5f7cd278..5d714e822e776d 100644
--- a/packages/react-components/react-textarea/src/components/Textarea/useTextarea.ts
+++ b/packages/react-components/react-textarea/src/components/Textarea/useTextarea.ts
@@ -6,6 +6,7 @@ import {
   useEventCallback,
 } from '@fluentui/react-utilities';
 import type { TextareaProps, TextareaState } from './Textarea.types';
+import { useOverrides_unstable as useOverrides } from '@fluentui/react-shared-contexts';
 
 /**
  * Create the state required to render Textarea.
@@ -17,7 +18,14 @@ import type { TextareaProps, TextareaState } from './Textarea.types';
  * @param ref - reference to root HTMLElement of Textarea
  */
 export const useTextarea_unstable = (props: TextareaProps, ref: React.Ref<HTMLTextAreaElement>): TextareaState => {
-  const { size = 'medium', appearance = 'outline', resize = 'none', onChange } = props;
+  const overrides = useOverrides();
+
+  const {
+    size = 'medium',
+    appearance = overrides.inputDefaultAppearance ?? 'outline',
+    resize = 'none',
+    onChange,
+  } = props;
 
   if (
     process.env.NODE_ENV !== 'production' &&