diff --git a/src/core/packages/chrome/layout/core-chrome-layout-components/sidebar/layout_sidebar.tsx b/src/core/packages/chrome/layout/core-chrome-layout-components/sidebar/layout_sidebar.tsx
index 15c6fb689fa58..f73b202cd267a 100644
--- a/src/core/packages/chrome/layout/core-chrome-layout-components/sidebar/layout_sidebar.tsx
+++ b/src/core/packages/chrome/layout/core-chrome-layout-components/sidebar/layout_sidebar.tsx
@@ -29,6 +29,7 @@ export const LayoutSidebar = ({ children }: LayoutSidebarProps) => {
       css={styles.root}
       className="kbnChromeLayoutSidebar"
       data-test-subj="kbnChromeLayoutSidebar"
+      data-kbn-preserve-zindex="true"
       {...euiIncludeSelectorInFocusTrap.prop}
     >
       {children}
diff --git a/src/core/packages/chrome/layout/core-chrome-layout/layouts/grid/grid_global_app_style.tsx b/src/core/packages/chrome/layout/core-chrome-layout/layouts/grid/grid_global_app_style.tsx
index 43e627ccb7593..4b851e46714fe 100644
--- a/src/core/packages/chrome/layout/core-chrome-layout/layouts/grid/grid_global_app_style.tsx
+++ b/src/core/packages/chrome/layout/core-chrome-layout/layouts/grid/grid_global_app_style.tsx
@@ -75,10 +75,11 @@ const globalLayoutStyles = (euiThemeContext: UseEuiTheme) => {
       position: relative; // This is temporary for apps that relied on this being present on \`.application\`
     }
 
-    // make data grid full screen mode respect the header banner
+    // make data grid full screen mode respect the header banner and the sidebar
     #kibana-body .euiDataGrid--fullScreen {
       height: calc(100vh - var(--kbnHeaderBannerHeight));
       top: var(--kbnHeaderBannerHeight);
+      right: ${layoutVar('sidebar.width', '0px')};
     }
   `;
 };
diff --git a/src/platform/packages/shared/kbn-unified-data-table/src/hooks/use_full_screen_watcher.ts b/src/platform/packages/shared/kbn-unified-data-table/src/hooks/use_full_screen_watcher.ts
index e349890b4533b..d526f9a307fe0 100644
--- a/src/platform/packages/shared/kbn-unified-data-table/src/hooks/use_full_screen_watcher.ts
+++ b/src/platform/packages/shared/kbn-unified-data-table/src/hooks/use_full_screen_watcher.ts
@@ -47,12 +47,16 @@ export const useFullScreenWatcher = () => {
 export const EUI_DATA_GRID_FULL_SCREEN_CLASS = 'euiDataGrid--fullScreen';
 export const UNIFIED_DATA_TABLE_FULL_SCREEN_CLASS = 'unifiedDataTable__fullScreen';
 
-// Ensure full screen data grids are not covered by elements with a z-index
+// Ensure full screen data grids are not covered by elements with a z-index.
+// Elements can opt out of the z-index reset by setting data-kbn-preserve-zindex="true",
+// which preserves their stacking context and that of their descendants.
 const fullScreenStyles = css`
   *:not(
       .${EUI_DATA_GRID_FULL_SCREEN_CLASS}, .${EUI_DATA_GRID_FULL_SCREEN_CLASS} *,
       [data-euiportal='true'],
-      [data-euiportal='true'] *
+      [data-euiportal='true'] *,
+      [data-kbn-preserve-zindex],
+      [data-kbn-preserve-zindex] *
     ) {
     z-index: unset !important;
   }