diff --git a/src/lib/components/TableToolbar.svelte b/src/lib/components/TableToolbar.svelte
index 415a814..e5411de 100644
--- a/src/lib/components/TableToolbar.svelte
+++ b/src/lib/components/TableToolbar.svelte
@@ -1,7 +1,7 @@
 <script lang="ts">
   import type { Editor, ChainedCommands } from '@tiptap/core';
   import { CellSelection } from '@tiptap/pm/tables';
-  import { isHeaderRowStyled } from '../editor/extensions/tableHeaderRow';
+  import { isHeaderStyled } from '../editor/extensions/tableHeaderRow';
   import ColorPicker from './ColorPicker.svelte';
   import TableBorderPicker from './TableBorderPicker.svelte';
   import { t } from '../i18n/i18n.svelte';
@@ -31,8 +31,9 @@
   // Merge needs a multi-cell selection; re-evaluated per transaction via `tick`.
   const canMerge = $derived(tick >= 0 && !!editor && editor.can().mergeCells());
 
-  // Whether the first row is styled as a header (bold + light shading).
-  const isHeaderRow = $derived(tick >= 0 && !!editor && isHeaderRowStyled(editor.state));
+  // Whether the first row / first column is styled as a header (bold + light shading).
+  const isHeaderRow = $derived(tick >= 0 && !!editor && isHeaderStyled(editor.state, 'row'));
+  const isHeaderCol = $derived(tick >= 0 && !!editor && isHeaderStyled(editor.state, 'column'));
 
   // Background colour of the selected cell(s): the uniform value, '' if mixed, null if
   // none. Drives the ColorPicker's "current" swatch (re-evaluated per `tick`).
@@ -235,6 +236,23 @@
       <line x1="9" y1="6.5" x2="9" y2="16.5" stroke="currentColor" stroke-width="1.1"/>
     </svg>
   </button>
+
+  <button
+    class="tt-btn"
+    class:active={isHeaderCol}
+    title={t().table.headerColumn}
+    aria-label={t().table.headerColumnAria}
+    aria-pressed={isHeaderCol}
+    onclick={() => run((c) => c.toggleHeaderColumnStyle())}
+  >
+    <svg width="18" height="18" viewBox="0 0 18 18" fill="none" aria-hidden="true">
+      <rect x="1.5" y="1.5" width="15" height="15" rx="1" stroke="currentColor" stroke-width="1.3"/>
+      <rect x="1.5" y="1.5" width="5" height="15" fill="currentColor" opacity="0.85"/>
+      <line x1="6.5" y1="1.5" x2="6.5" y2="16.5" stroke="currentColor" stroke-width="1.1"/>
+      <line x1="11.5" y1="1.5" x2="11.5" y2="16.5" stroke="currentColor" stroke-width="1.1"/>
+      <line x1="6.5" y1="9" x2="16.5" y2="9" stroke="currentColor" stroke-width="1.1"/>
+    </svg>
+  </button>
 </div>
 
 <style>
diff --git a/src/lib/editor/extensions/tableHeaderRow.ts b/src/lib/editor/extensions/tableHeaderRow.ts
index 28cb880..0aea166 100644
--- a/src/lib/editor/extensions/tableHeaderRow.ts
+++ b/src/lib/editor/extensions/tableHeaderRow.ts
@@ -3,34 +3,38 @@ import type { CommandProps } from '@tiptap/core';
 import type { EditorState } from '@tiptap/pm/state';
 import { selectedRect, isInTable } from '@tiptap/pm/tables';
 
-// Word/LibreOffice-style "header row" as a styling preset: the first row gets bold text
-// + a light grey fill. This is real formatting (bold mark + the backgroundColor cell
-// attr from tableCellBackground.ts), both of which already round-trip to/from ODF — so
-// the editor and the exported .odt look identical, with no page repetition (we
-// deliberately don't emit <table:table-header-rows>, which is what makes Word repeat it).
-// The shading doubles as the toggle's marker, so the active state survives save/reopen.
+// Word/LibreOffice "header row"/"header column" as a styling preset: the first row (or
+// column) gets bold text + a light grey fill, both of which round-trip to ODF/DOCX. The
+// fill doubles as the marker, so no <table:table-header-rows> and no page repetition.
 
 export const HEADER_SHADE = '#F2F2F2';
 
+export type HeaderAxis = 'row' | 'column';
+
 declare module '@tiptap/core' {
   interface Commands<ReturnType> {
     tableHeaderRow: {
       toggleHeaderRowStyle: () => ReturnType;
+      toggleHeaderColumnStyle: () => ReturnType;
     };
   }
 }
 
-// Distinct cell positions (relative to tableStart) of the table's first row.
-function firstRowCellPositions(state: EditorState): { positions: number[]; tableStart: number } | null {
+// Distinct cell positions (relative to tableStart) of the table's first row / first column.
+function headerCellPositions(
+  state: EditorState,
+  axis: HeaderAxis,
+): { positions: number[]; tableStart: number; corner: number } | null {
   if (!isInTable(state)) return null;
   const { map, tableStart } = selectedRect(state);
   const seen = new Set<number>();
   const positions: number[] = [];
-  for (let c = 0; c < map.width; c++) {
-    const pos = map.map[c];
+  const n = axis === 'row' ? map.width : map.height;
+  for (let i = 0; i < n; i++) {
+    const pos = map.map[axis === 'row' ? i : i * map.width];
     if (!seen.has(pos)) { seen.add(pos); positions.push(pos); }
   }
-  return { positions, tableStart };
+  return { positions, tableStart, corner: map.map[0] };
 }
 
 // True when the cursor sits in a header-shaded cell (so the Bold button should drive the
@@ -46,33 +50,37 @@ export function isInHeaderCell(state: EditorState): boolean {
   return false;
 }
 
-// True when every cell of the first row carries the header fill.
-export function isHeaderRowStyled(state: EditorState): boolean {
-  const info = firstRowCellPositions(state);
+// True when every cell of the first row / first column carries the header fill.
+export function isHeaderStyled(state: EditorState, axis: HeaderAxis): boolean {
+  const info = headerCellPositions(state, axis);
   if (!info || info.positions.length === 0) return false;
   return info.positions.every(
     (p) => state.doc.nodeAt(info.tableStart + p)?.attrs.backgroundColor === HEADER_SHADE,
   );
 }
 
-export function toggleHeaderRowStyle() {
+export function toggleHeaderStyle(axis: HeaderAxis) {
   return ({ state, tr, dispatch }: CommandProps): boolean => {
-    const info = firstRowCellPositions(state);
+    const info = headerCellPositions(state, axis);
     if (!info) return false;
     if (!dispatch) return true;
 
-    const isHeader = isHeaderRowStyled(state);
+    const isHeader = isHeaderStyled(state, axis);
+    // The corner cell belongs to both headers, so turning one off must leave it alone
+    // while the other is still on.
+    const keepCorner = isHeader && isHeaderStyled(state, axis === 'row' ? 'column' : 'row');
     const bold = state.schema.marks.bold;
     // The fill is the header marker; bold is presentational (CSS on `.cell-header`, keyed
     // off this fill) so it covers existing, typed, and pasted text alike. setNodeMarkup/
     // removeMark don't shift positions, so the original cell positions stay valid.
     for (const p of info.positions) {
+      if (keepCorner && p === info.corner) continue;
       const cellPos = info.tableStart + p;
       const cell = tr.doc.nodeAt(cellPos);
       if (!cell) continue;
       tr.setNodeMarkup(cellPos, undefined, { ...cell.attrs, backgroundColor: isHeader ? null : HEADER_SHADE });
       // Turning off: strip any bold marks (incl. ones baked into the runs on export and
-      // read back on import) so the row truly returns to normal.
+      // read back on import) so the cells truly return to normal.
       if (isHeader && bold) tr.removeMark(cellPos + 1, cellPos + cell.nodeSize - 1, bold);
     }
     dispatch(tr);
@@ -85,7 +93,8 @@ export const TableHeaderRow = Extension.create({
 
   addCommands() {
     return {
-      toggleHeaderRowStyle: () => toggleHeaderRowStyle(),
+      toggleHeaderRowStyle: () => toggleHeaderStyle('row'),
+      toggleHeaderColumnStyle: () => toggleHeaderStyle('column'),
     };
   },
 });
diff --git a/src/lib/i18n/locales/de.ts b/src/lib/i18n/locales/de.ts
index af929a2..4c2ce7a 100644
--- a/src/lib/i18n/locales/de.ts
+++ b/src/lib/i18n/locales/de.ts
@@ -240,6 +240,8 @@ const de: Messages = {
     noFill: 'Keine Füllung',
     headerRow: 'Kopfzeile (fett + Schattierung)',
     headerRowAria: 'Kopfzeile',
+    headerColumn: 'Kopfspalte (fett + Schattierung)',
+    headerColumnAria: 'Kopfspalte',
     insertTable: 'Tabelle einfügen',
     selectSize: 'Tabellengröße wählen',
     dimensions: (cols, rows) => `${cols} × ${rows}`,
diff --git a/src/lib/i18n/locales/en.ts b/src/lib/i18n/locales/en.ts
index 5596732..07fb4f7 100644
--- a/src/lib/i18n/locales/en.ts
+++ b/src/lib/i18n/locales/en.ts
@@ -244,6 +244,8 @@ const en = {
     noFill: 'No fill',
     headerRow: 'Header row (bold + shading)',
     headerRowAria: 'Header row',
+    headerColumn: 'Header column (bold + shading)',
+    headerColumnAria: 'Header column',
     insertTable: 'Insert table',
     selectSize: 'Select table size',
     dimensions: (cols: number, rows: number) => `${cols} × ${rows}`,
diff --git a/tests/unit/table-header-row.test.ts b/tests/unit/table-header-row.test.ts
index 884bb7e..b8b1575 100644
--- a/tests/unit/table-header-row.test.ts
+++ b/tests/unit/table-header-row.test.ts
@@ -13,8 +13,9 @@ import { ResizableTableRow } from '../../src/lib/editor/extensions/tableRow';
 import { TableCellBackground } from '../../src/lib/editor/extensions/tableCellBackground';
 import {
   HEADER_SHADE,
-  isHeaderRowStyled,
-  toggleHeaderRowStyle,
+  isHeaderStyled,
+  toggleHeaderStyle,
+  type HeaderAxis,
 } from '../../src/lib/editor/extensions/tableHeaderRow';
 
 type N = any;
@@ -43,12 +44,14 @@ function makeState(): EditorState {
 }
 
 // Apply the command factory to a state, returning the next state.
-function run(state: EditorState): EditorState {
+function run(state: EditorState, axis: HeaderAxis = 'row'): EditorState {
   let next: EditorState | null = null;
-  toggleHeaderRowStyle()({ state, tr: state.tr, dispatch: (tr: any) => { next = state.apply(tr); } } as any);
+  toggleHeaderStyle(axis)({ state, tr: state.tr, dispatch: (tr: any) => { next = state.apply(tr); } } as any);
   return next ?? state;
 }
 
+const isHeaderRowStyled = (s: EditorState) => isHeaderStyled(s, 'row');
+
 const firstRow = (state: EditorState): N => state.doc.toJSON().content[0].content[0];
 const boldMarks = (c: N): boolean => (c.content[0].content[0]?.marks ?? []).some((m: N) => m.type === 'bold');
 
@@ -98,4 +101,25 @@ describe('toggleHeaderRowStyle', () => {
     expect(c.attrs.backgroundColor == null).toBe(true);
     expect(boldMarks(c)).toBe(false); // baked bold removed
   });
+
+  it('toggles the first column, and the shared corner survives turning one off', () => {
+    let state = makeState();
+    state = run(state, 'column');
+    expect(isHeaderStyled(state, 'column')).toBe(true);
+    const col = (s: EditorState) => s.doc.toJSON().content[0].content.map((r: N) => r.content[0]);
+    for (const c of col(state)) expect(c.attrs.backgroundColor).toBe(HEADER_SHADE);
+    // Cell (0,1) untouched.
+    expect(state.doc.toJSON().content[0].content[0].content[1].attrs.backgroundColor == null).toBe(true);
+
+    // Both headers on: turning the row off keeps the corner (still the column header).
+    state = run(state, 'row');
+    expect(isHeaderStyled(state, 'row')).toBe(true);
+    state = run(state, 'row');
+    expect(isHeaderStyled(state, 'row')).toBe(false);
+    expect(isHeaderStyled(state, 'column')).toBe(true);
+
+    state = run(state, 'column');
+    expect(isHeaderStyled(state, 'column')).toBe(false);
+    for (const c of col(state)) expect(c.attrs.backgroundColor == null).toBe(true);
+  });
 });