diff --git a/packages/eui/.loki/reference/chrome_desktop_Tabular_Content_EuiDataGrid_Visible_Columns.png b/packages/eui/.loki/reference/chrome_desktop_Tabular_Content_EuiDataGrid_Visible_Columns.png
new file mode 100644
index 00000000000..449826e2cc9
Binary files /dev/null and b/packages/eui/.loki/reference/chrome_desktop_Tabular_Content_EuiDataGrid_Visible_Columns.png differ
diff --git a/packages/eui/.loki/reference/chrome_mobile_Tabular_Content_EuiDataGrid_Visible_Columns.png b/packages/eui/.loki/reference/chrome_mobile_Tabular_Content_EuiDataGrid_Visible_Columns.png
new file mode 100644
index 00000000000..30a9077872d
Binary files /dev/null and b/packages/eui/.loki/reference/chrome_mobile_Tabular_Content_EuiDataGrid_Visible_Columns.png differ
diff --git a/packages/eui/changelogs/upcoming/9209.md b/packages/eui/changelogs/upcoming/9209.md
new file mode 100644
index 00000000000..82afe2af595
--- /dev/null
+++ b/packages/eui/changelogs/upcoming/9209.md
@@ -0,0 +1,4 @@
+**Bug fixes**
+
+- Fixed unexpected duplicate columns in `EuiDataGrid` crashing the column sorting by removing duplicate columns entirely
+
diff --git a/packages/eui/src/components/datagrid/controls/column_selector.tsx b/packages/eui/src/components/datagrid/controls/column_selector.tsx
index 5ff1bdfc568..51a59de176f 100644
--- a/packages/eui/src/components/datagrid/controls/column_selector.tsx
+++ b/packages/eui/src/components/datagrid/controls/column_selector.tsx
@@ -64,22 +64,45 @@ export const useDataGridColumnSelector = (
 
   const [sortedColumns, setSortedColumns] = useDependentState(() => {
     const availableColumnIds = availableColumns.map(({ id }) => id);
-    const availableSet = new Set(availableColumnIds);
-    // Filter visibleColumns to only include existing columns
+    // remove duplicate columns to ensure unique columns
+    const availableColumnIdsSet = new Set(availableColumnIds);
+
+    if (process.env.NODE_ENV === 'development') {
+      if (availableColumnIds.length > availableColumnIdsSet.size) {
+        const duplicateIds: string[] = [];
+
+        for (const id of availableColumnIds) {
+          if (
+            !duplicateIds.includes(id) &&
+            availableColumnIds.filter((_id) => _id === id).length > 1
+          ) {
+            duplicateIds.push(id);
+          }
+        }
+
+        console.warn(
+          `⚠️ EuiDataGrid: Duplicate column IDs detected and removed: ${duplicateIds.join(
+            ', '
+          )}.`,
+          '\n Column IDs must be unique. Only the first occurrence of each duplicate will be used.'
+        );
+      }
+    }
+
     const validVisibleColumns = visibleColumns.filter((id) =>
-      availableSet.has(id)
+      availableColumnIdsSet.has(id)
     );
     const visibleSet = new Set(validVisibleColumns);
 
     const result: string[] = [];
     let visibleIndex = 0;
 
-    for (const columnId of availableColumnIds) {
+    for (const columnId of [...availableColumnIdsSet]) {
       if (visibleSet.has(columnId)) {
-        // Replace with next visible column in order
-        result.push(validVisibleColumns[visibleIndex++]);
+        if (visibleIndex < validVisibleColumns.length) {
+          result.push(validVisibleColumns[visibleIndex++]);
+        }
       } else {
-        // Keep hidden column in original position
         result.push(columnId);
       }
     }
@@ -170,8 +193,8 @@ export const useDataGridColumnSelector = (
           <EuiDataGridToolbarControl
             badgeContent={
               numberOfHiddenFields > 0
-                ? `${orderedVisibleColumns.length}/${availableColumns.length}`
-                : availableColumns.length
+                ? `${orderedVisibleColumns.length}/${sortedColumns.length}`
+                : sortedColumns.length
             }
             iconType="tableDensityNormal"
             data-test-subj="dataGridColumnSelectorButton"
diff --git a/packages/eui/src/components/datagrid/data_grid.spec.tsx b/packages/eui/src/components/datagrid/data_grid.spec.tsx
index 71399fbbabe..74c320d3b1a 100644
--- a/packages/eui/src/components/datagrid/data_grid.spec.tsx
+++ b/packages/eui/src/components/datagrid/data_grid.spec.tsx
@@ -805,7 +805,7 @@ a, footer\tb, footer
       ).should('have.attr', 'aria-checked', 'false');
     });
 
-    it('renders columns in the corect order when `columns` and `visibleColumns` have different orders', () => {
+    it('renders columns in the correct order when `columns` and `visibleColumns` have different orders', () => {
       cy.mount(
         <StatefulDataGrid
           {...props}
@@ -839,6 +839,57 @@ a, footer\tb, footer
       ).should('have.attr', 'aria-checked', 'false');
     });
 
+    it('removes duplicates from `columns` with equal `id`', () => {
+      cy.mount(
+        <StatefulDataGrid
+          {...props}
+          columns={[
+            { id: 'a', display: 'First' },
+            { id: 'b', display: 'Second.A' },
+            { id: 'b', display: 'Second.B' },
+            { id: 'c', display: 'Third' },
+            { id: 'd', display: 'Fourth' },
+          ]}
+          columnVisibility={{
+            ...props.columnVisibility,
+            visibleColumns: ['b', 'd', 'a'],
+          }}
+        />
+      );
+
+      cy.get(
+        '[data-gridcell-column-index="0"][data-gridcell-visible-row-index="-1"] .euiDataGridHeaderCell__content'
+      ).should('have.text', 'Second.A');
+      cy.get(
+        '[data-gridcell-column-index="1"][data-gridcell-visible-row-index="-1"] .euiDataGridHeaderCell__content'
+      ).should('have.text', 'Fourth');
+      cy.get(
+        '[data-gridcell-column-index="2"][data-gridcell-visible-row-index="-1"] .euiDataGridHeaderCell__content'
+      ).should('have.text', 'First');
+
+      cy.get('.euiNotificationBadge').then(($items) => {
+        const textContent = $items.text();
+        expect(textContent).to.equal('3/4');
+      });
+
+      /* checks column selector popover order */
+      cy.get('[data-test-subj="dataGridColumnSelectorButton"]').click();
+
+      cy.get('.euiDataGridColumnSelector__item').then(($items) => {
+        const columnsCount = $items.length;
+        expect(columnsCount).to.equal(4);
+      });
+
+      cy.get('.euiDataGridColumnSelector__item').eq(0).should('have.text', 'b');
+      cy.get('.euiDataGridColumnSelector__item').eq(1).should('have.text', 'd');
+      cy.get('.euiDataGridColumnSelector__item').eq(2).should('have.text', 'c');
+      cy.get('.euiDataGridColumnSelector__item').eq(3).should('have.text', 'a');
+
+      cy.get(
+        '.euiDataGridColumnSelector__item [data-test-subj="dataGridColumnSelectorToggleColumnVisibility-c"]'
+      ).should('have.attr', 'aria-checked', 'false');
+    });
+
     it('reorders columns from the column selector', () => {
       cy.mount(<StatefulDataGrid {...props} />);
 
diff --git a/packages/eui/src/components/datagrid/data_grid.stories.tsx b/packages/eui/src/components/datagrid/data_grid.stories.tsx
index baf139384cb..cae8d23a61f 100644
--- a/packages/eui/src/components/datagrid/data_grid.stories.tsx
+++ b/packages/eui/src/components/datagrid/data_grid.stories.tsx
@@ -9,7 +9,7 @@
 import React, { useRef, useEffect } from 'react';
 import { css } from '@emotion/react';
 import type { Meta, StoryObj, ReactRenderer } from '@storybook/react';
-import type { PlayFunctionContext } from '@storybook/csf';
+import { StoryContext } from '@storybook/csf';
 import { expect, fireEvent, waitFor } from '@storybook/test';
 import { action } from '@storybook/addon-actions';
 import { within } from '../../../.storybook/test';
@@ -176,7 +176,7 @@ export const DraggableColumns: Story = {
     ),
   },
   render: (args: EuiDataGridProps) => <StatefulDataGrid {...args} />,
-  play: async ({ canvasElement }: PlayFunctionContext<ReactRenderer>) => {
+  play: async ({ canvasElement }: StoryContext<ReactRenderer>) => {
     const canvas = within(canvasElement);
 
     await waitFor(async () => {
@@ -231,9 +231,37 @@ export const ColumnActions: Story = {
       gridStyle={{ fontSize: 's', cellPadding: 's' }}
     />
   ),
-  play: async ({ canvasElement }: PlayFunctionContext<ReactRenderer>) => {
+  play: async ({ canvasElement }: StoryContext<ReactRenderer>) => {
     const canvas = within(canvasElement);
     await canvas.waitForAndClick('dataGridHeaderCellActionButton-account');
     await canvas.waitForEuiPopoverVisible();
   },
 };
+
+export const VisibleColumns: Story = {
+  tags: ['vrt-only'],
+  args: {
+    ...defaultStorybookArgs,
+    columnVisibility: {
+      // `visibleColumns` has a different order than `columns` - `visibleColumns` determines the order
+      visibleColumns: ['date', 'name', 'email', 'location'],
+      setVisibleColumns: action('setVisibleColumns'),
+    },
+    // `columns` contains duplicates - only the first occurrence is used
+    columns: [
+      { id: 'name', displayAsText: 'Name' },
+      { id: 'email', displayAsText: 'Email' },
+      { id: 'location', displayAsText: 'Location' },
+      { id: 'name', displayAsText: 'Name (duplicate)' },
+      { id: 'email', displayAsText: 'Email (duplicate)' },
+      { id: 'account', displayAsText: 'Account' },
+      { id: 'date', displayAsText: 'Date' },
+    ],
+  },
+  render: (args: EuiDataGridProps) => <StatefulDataGrid {...args} />,
+  play: async ({ canvasElement }: StoryContext<ReactRenderer>) => {
+    const canvas = within(canvasElement);
+    await canvas.waitForAndClick('dataGridColumnSelectorButton');
+    await canvas.waitForEuiPopoverVisible();
+  },
+};
diff --git a/packages/eui/src/components/datagrid/data_grid.tsx b/packages/eui/src/components/datagrid/data_grid.tsx
index 2976c630f68..abfecb53c2f 100644
--- a/packages/eui/src/components/datagrid/data_grid.tsx
+++ b/packages/eui/src/components/datagrid/data_grid.tsx
@@ -210,10 +210,17 @@ export const EuiDataGrid = memo(
      */
     const displayValues: { [key: string]: string } = useMemo(() => {
       return columns.reduce(
-        (acc: { [key: string]: string }, column: EuiDataGridColumn) => ({
-          ...acc,
-          [column.id]: column.displayAsText || column.id,
-        }),
+        (acc: { [key: string]: string }, column: EuiDataGridColumn) => {
+          // prevent duplicate values
+          if (!acc[column.id]) {
+            return {
+              ...acc,
+              [column.id]: column.displayAsText || column.id,
+            };
+          }
+
+          return acc;
+        },
         {}
       );
     }, [columns]);
diff --git a/packages/eui/src/components/datagrid/utils/in_memory.tsx b/packages/eui/src/components/datagrid/utils/in_memory.tsx
index 33d840e0901..b5a4a5c082f 100644
--- a/packages/eui/src/components/datagrid/utils/in_memory.tsx
+++ b/packages/eui/src/components/datagrid/utils/in_memory.tsx
@@ -100,6 +100,7 @@ export const EuiDataGridInMemoryRenderer: FunctionComponent<
       cells.push(
         columns
           .map((column, j) => {
+            const key = `${i}-${j}-${column.id}`;
             const skipThisColumn =
               inMemory.skipColumns &&
               inMemory.skipColumns.indexOf(column.id) !== -1;
@@ -112,11 +113,7 @@ export const EuiDataGridInMemoryRenderer: FunctionComponent<
               column.isExpandable !== undefined ? column.isExpandable : true;
 
             return (
-              <div
-                key={`${i}-${column.id}`}
-                data-dg-row={i}
-                data-dg-column={column.id}
-              >
+              <div key={key} data-dg-row={i} data-dg-column={column.id}>
                 <CellElement
                   rowIndex={i}
                   colIndex={j}