diff --git a/packages/x-tree-view/src/TreeItem/TreeItem.tsx b/packages/x-tree-view/src/TreeItem/TreeItem.tsx
index 6cc7d7cbec99..898f14212517 100644
--- a/packages/x-tree-view/src/TreeItem/TreeItem.tsx
+++ b/packages/x-tree-view/src/TreeItem/TreeItem.tsx
@@ -199,7 +199,7 @@ export const TreeItem = React.forwardRef(function TreeItem(
     icons: contextIcons,
     runItemPlugins,
     items: { disabledItemsFocusable, indentationAtItemLevel },
-    selection: { multiSelect },
+    selection: { disableSelection },
     expansion: { expansionTrigger },
     treeId,
     instance,
@@ -358,17 +358,17 @@ export const TreeItem = React.forwardRef(function TreeItem(
   });
   const icon = Icon ? <Icon {...iconProps} /> : null;
 
-  let ariaSelected;
-  if (multiSelect) {
-    ariaSelected = selected;
-  } else if (selected) {
-    /* single-selection trees unset aria-selected on un-selected items.
-     *
-     * If the tree does not support multiple selection, aria-selected
-     * is set to true for the selected item and it is not present on any other item in the tree.
-     * Source: https://www.w3.org/WAI/ARIA/apg/patterns/treeview/
-     */
+  // https://www.w3.org/WAI/ARIA/apg/patterns/treeview/
+  let ariaSelected: boolean | undefined;
+  if (selected) {
+    // - each selected node has aria-selected set to true.
     ariaSelected = true;
+  } else if (disableSelection || disabled) {
+    // - if the tree contains nodes that are not selectable, aria-selected is not present on those nodes.
+    ariaSelected = undefined;
+  } else {
+    // - all nodes that are selectable but not selected have aria-selected set to false.
+    ariaSelected = false;
   }
 
   function handleFocus(event: React.FocusEvent<HTMLLIElement>) {
diff --git a/packages/x-tree-view/src/internals/plugins/useTreeViewSelection/useTreeViewSelection.test.tsx b/packages/x-tree-view/src/internals/plugins/useTreeViewSelection/useTreeViewSelection.test.tsx
index 0f80094dc69a..448178c94601 100644
--- a/packages/x-tree-view/src/internals/plugins/useTreeViewSelection/useTreeViewSelection.test.tsx
+++ b/packages/x-tree-view/src/internals/plugins/useTreeViewSelection/useTreeViewSelection.test.tsx
@@ -712,12 +712,12 @@ describeTreeView<[UseTreeViewSelectionSignature, UseTreeViewExpansionSignature]>
     // This `describe` only tests basics scenarios, more complex scenarios are tested in this file's other `describe`.
     describe('aria-selected item attribute', () => {
       describe('single selection', () => {
-        it('should not have the attribute `aria-selected=false` if not selected', () => {
+        it('should have the attribute `aria-selected=false` if not selected', () => {
           const view = render({
             items: [{ id: '1' }, { id: '2' }],
           });
 
-          expect(view.getItemRoot('1')).not.to.have.attribute('aria-selected');
+          expect(view.getItemRoot('1')).to.have.attribute('aria-selected', 'false');
         });
 
         it('should have the attribute `aria-selected=true` if selected', () => {
@@ -750,14 +750,23 @@ describeTreeView<[UseTreeViewSelectionSignature, UseTreeViewExpansionSignature]>
           expect(view.getItemRoot('1')).to.have.attribute('aria-selected', 'true');
         });
 
-        it('should have the attribute `aria-selected=false` if disabledSelection is true', () => {
+        it('should not have the attribute `aria-selected=false` if disabledSelection is true', () => {
           const view = render({
             multiSelect: true,
             items: [{ id: '1' }, { id: '2' }],
             disableSelection: true,
           });
 
-          expect(view.getItemRoot('1')).to.have.attribute('aria-selected', 'false');
+          expect(view.getItemRoot('1')).not.to.have.attribute('aria-selected');
+        });
+
+        it('should not have the attribute `aria-selected=false` if the item is disabled', () => {
+          const view = render({
+            multiSelect: true,
+            items: [{ id: '1', disabled: true }, { id: '2' }],
+          });
+
+          expect(view.getItemRoot('1')).not.to.have.attribute('aria-selected');
         });
       });
     });
diff --git a/packages/x-tree-view/src/useTreeItem2/useTreeItem2.ts b/packages/x-tree-view/src/useTreeItem2/useTreeItem2.ts
index a8b8fff491e4..674f7380b39f 100644
--- a/packages/x-tree-view/src/useTreeItem2/useTreeItem2.ts
+++ b/packages/x-tree-view/src/useTreeItem2/useTreeItem2.ts
@@ -37,7 +37,7 @@ export const useTreeItem2 = <
   const {
     runItemPlugins,
     items: { onItemClick, disabledItemsFocusable, indentationAtItemLevel },
-    selection: { multiSelect, disableSelection, checkboxSelection },
+    selection: { disableSelection, checkboxSelection },
     expansion: { expansionTrigger },
     treeId,
     instance,
@@ -194,17 +194,17 @@ export const useTreeItem2 = <
       ...extractEventHandlers(externalProps),
     };
 
+    // https://www.w3.org/WAI/ARIA/apg/patterns/treeview/
     let ariaSelected: boolean | undefined;
-    if (multiSelect) {
-      ariaSelected = status.selected;
-    } else if (status.selected) {
-      /* single-selection trees unset aria-selected on un-selected items.
-       *
-       * If the tree does not support multiple selection, aria-selected
-       * is set to true for the selected item and it is not present on any other item in the tree.
-       * Source: https://www.w3.org/WAI/ARIA/apg/patterns/treeview/
-       */
+    if (status.selected) {
+      // - each selected node has aria-selected set to true.
       ariaSelected = true;
+    } else if (disableSelection || status.disabled) {
+      // - if the tree contains nodes that are not selectable, aria-selected is not present on those nodes.
+      ariaSelected = undefined;
+    } else {
+      // - all nodes that are selectable but not selected have aria-selected set to false.
+      ariaSelected = false;
     }
 
     const props: UseTreeItem2RootSlotPropsFromUseTreeItem = {