diff --git a/invokeai/frontend/web/src/features/nodes/components/flow/panels/TopPanel/SaveWorkflowButton.tsx b/invokeai/frontend/web/src/features/nodes/components/flow/panels/TopPanel/SaveWorkflowButton.tsx
index 91c6c1dae38..fe4b889f540 100644
--- a/invokeai/frontend/web/src/features/nodes/components/flow/panels/TopPanel/SaveWorkflowButton.tsx
+++ b/invokeai/frontend/web/src/features/nodes/components/flow/panels/TopPanel/SaveWorkflowButton.tsx
@@ -1,5 +1,6 @@
 import { IconButton } from '@invoke-ai/ui-library';
 import { useDoesWorkflowHaveUnsavedChanges } from 'features/nodes/components/sidePanel/workflow/IsolatedWorkflowBuilderWatcher';
+import { useIsCurrentWorkflowOwner } from 'features/workflowLibrary/hooks/useIsCurrentWorkflowOwner';
 import { useSaveOrSaveAsWorkflow } from 'features/workflowLibrary/hooks/useSaveOrSaveAsWorkflow';
 import { memo } from 'react';
 import { useTranslation } from 'react-i18next';
@@ -8,6 +9,7 @@ import { PiFloppyDiskBold } from 'react-icons/pi';
 const SaveWorkflowButton = () => {
   const { t } = useTranslation();
   const doesWorkflowHaveUnsavedChanges = useDoesWorkflowHaveUnsavedChanges();
+  const isCurrentWorkflowOwner = useIsCurrentWorkflowOwner();
   const saveOrSaveAsWorkflow = useSaveOrSaveAsWorkflow();
 
   return (
@@ -15,7 +17,7 @@ const SaveWorkflowButton = () => {
       tooltip={t('workflows.saveWorkflow')}
       aria-label={t('workflows.saveWorkflow')}
       icon={<PiFloppyDiskBold />}
-      isDisabled={!doesWorkflowHaveUnsavedChanges}
+      isDisabled={!doesWorkflowHaveUnsavedChanges || !isCurrentWorkflowOwner}
       onClick={saveOrSaveAsWorkflow}
       pointerEvents="auto"
     />
diff --git a/invokeai/frontend/web/src/features/nodes/components/sidePanel/WorkflowListMenu/SaveWorkflowButton.tsx b/invokeai/frontend/web/src/features/nodes/components/sidePanel/WorkflowListMenu/SaveWorkflowButton.tsx
index 39a93e4a382..779d6f018ee 100644
--- a/invokeai/frontend/web/src/features/nodes/components/sidePanel/WorkflowListMenu/SaveWorkflowButton.tsx
+++ b/invokeai/frontend/web/src/features/nodes/components/sidePanel/WorkflowListMenu/SaveWorkflowButton.tsx
@@ -1,4 +1,6 @@
 import { IconButton } from '@invoke-ai/ui-library';
+import { useDoesWorkflowHaveUnsavedChanges } from 'features/nodes/components/sidePanel/workflow/IsolatedWorkflowBuilderWatcher';
+import { useIsCurrentWorkflowOwner } from 'features/workflowLibrary/hooks/useIsCurrentWorkflowOwner';
 import { useSaveOrSaveAsWorkflow } from 'features/workflowLibrary/hooks/useSaveOrSaveAsWorkflow';
 import { memo } from 'react';
 import { useTranslation } from 'react-i18next';
@@ -7,12 +9,15 @@ import { PiFloppyDiskBold } from 'react-icons/pi';
 const SaveWorkflowButton = () => {
   const { t } = useTranslation();
   const saveOrSaveAsWorkflow = useSaveOrSaveAsWorkflow();
+  const doesWorkflowHaveUnsavedChanges = useDoesWorkflowHaveUnsavedChanges();
+  const isCurrentWorkflowOwner = useIsCurrentWorkflowOwner();
 
   return (
     <IconButton
       tooltip={t('workflows.saveWorkflow')}
       aria-label={t('workflows.saveWorkflow')}
       icon={<PiFloppyDiskBold />}
+      isDisabled={!doesWorkflowHaveUnsavedChanges || !isCurrentWorkflowOwner}
       onClick={saveOrSaveAsWorkflow}
       pointerEvents="auto"
       variant="ghost"
diff --git a/invokeai/frontend/web/src/features/workflowLibrary/components/WorkflowLibraryMenu/SaveWorkflowMenuItem.tsx b/invokeai/frontend/web/src/features/workflowLibrary/components/WorkflowLibraryMenu/SaveWorkflowMenuItem.tsx
index 6f5acc431ed..e683cfdbefd 100644
--- a/invokeai/frontend/web/src/features/workflowLibrary/components/WorkflowLibraryMenu/SaveWorkflowMenuItem.tsx
+++ b/invokeai/frontend/web/src/features/workflowLibrary/components/WorkflowLibraryMenu/SaveWorkflowMenuItem.tsx
@@ -1,5 +1,6 @@
 import { MenuItem } from '@invoke-ai/ui-library';
 import { useDoesWorkflowHaveUnsavedChanges } from 'features/nodes/components/sidePanel/workflow/IsolatedWorkflowBuilderWatcher';
+import { useIsCurrentWorkflowOwner } from 'features/workflowLibrary/hooks/useIsCurrentWorkflowOwner';
 import { useSaveOrSaveAsWorkflow } from 'features/workflowLibrary/hooks/useSaveOrSaveAsWorkflow';
 import { memo } from 'react';
 import { useTranslation } from 'react-i18next';
@@ -9,11 +10,12 @@ const SaveWorkflowMenuItem = () => {
   const { t } = useTranslation();
   const saveOrSaveAsWorkflow = useSaveOrSaveAsWorkflow();
   const doesWorkflowHaveUnsavedChanges = useDoesWorkflowHaveUnsavedChanges();
+  const isCurrentWorkflowOwner = useIsCurrentWorkflowOwner();
 
   return (
     <MenuItem
       as="button"
-      isDisabled={!doesWorkflowHaveUnsavedChanges}
+      isDisabled={!doesWorkflowHaveUnsavedChanges || !isCurrentWorkflowOwner}
       icon={<PiFloppyDiskBold />}
       onClick={saveOrSaveAsWorkflow}
     >
diff --git a/invokeai/frontend/web/src/features/workflowLibrary/hooks/useIsCurrentWorkflowOwner.ts b/invokeai/frontend/web/src/features/workflowLibrary/hooks/useIsCurrentWorkflowOwner.ts
new file mode 100644
index 00000000000..5183c9050b7
--- /dev/null
+++ b/invokeai/frontend/web/src/features/workflowLibrary/hooks/useIsCurrentWorkflowOwner.ts
@@ -0,0 +1,48 @@
+import { skipToken } from '@reduxjs/toolkit/query';
+import { useAppSelector } from 'app/store/storeHooks';
+import { selectCurrentUser } from 'features/auth/store/authSlice';
+import { selectWorkflowId } from 'features/nodes/store/selectors';
+import { useMemo } from 'react';
+import { useGetSetupStatusQuery } from 'services/api/endpoints/auth';
+import { useGetWorkflowQuery } from 'services/api/endpoints/workflows';
+
+/**
+ * Returns true if the current user can save the currently-loaded workflow directly (not as a copy).
+ *
+ * In single-user mode, this always returns true.
+ * In multiuser mode, returns true when:
+ * - The workflow has no ID (new, unsaved workflow — will open Save As)
+ * - The current user is the owner of the workflow
+ * - The current user is an admin
+ */
+export const useIsCurrentWorkflowOwner = (): boolean => {
+  const workflowId = useAppSelector(selectWorkflowId);
+  const currentUser = useAppSelector(selectCurrentUser);
+  const { data: setupStatus } = useGetSetupStatusQuery();
+  const { data: workflowData } = useGetWorkflowQuery(workflowId ?? skipToken);
+
+  return useMemo(() => {
+    // In single-user mode there is no concept of ownership, so saving is always allowed.
+    if (!setupStatus?.multiuser_enabled) {
+      return true;
+    }
+
+    // No authenticated user — be permissive.
+    if (!currentUser) {
+      return true;
+    }
+
+    // No workflow ID means this is a new/unsaved workflow. Clicking "Save" will open the
+    // Save As dialog, so we should not block it.
+    if (!workflowId) {
+      return true;
+    }
+
+    // API data not yet available — be permissive to avoid incorrect disabling during loading.
+    if (!workflowData) {
+      return true;
+    }
+
+    return workflowData.user_id === currentUser.user_id || currentUser.is_admin;
+  }, [setupStatus?.multiuser_enabled, workflowId, workflowData, currentUser]);
+};