diff --git a/app/src/hooks/useProfileSettings.test.ts b/app/src/hooks/useProfileSettings.test.ts
new file mode 100644
index 0000000..54500fb
--- /dev/null
+++ b/app/src/hooks/useProfileSettings.test.ts
@@ -0,0 +1,517 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { renderHook, act } from '@testing-library/react';
+import { useProfileSettings } from './useProfileSettings';
+import * as userApi from '@/api/user';
+import type { UpdateProfileRequest } from '@/types/api';
+import { UserRole, type User } from '@/types/models';
+
+// Mock dependencies
+vi.mock('@/api/user');
+vi.mock('@mantine/notifications', () => ({
+  notifications: {
+    show: vi.fn(),
+  },
+}));
+
+// Import notifications for assertions
+import { notifications } from '@mantine/notifications';
+
+// Mock user data
+const mockUser: User = {
+  id: 1,
+  email: 'test@example.com',
+  displayName: 'Test User',
+  role: UserRole.Editor,
+  createdAt: '2024-01-01T00:00:00Z',
+  lastWorkspaceId: 1,
+};
+
+describe('useProfileSettings', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  describe('initial state', () => {
+    it('returns correct initial loading state', () => {
+      const { result } = renderHook(() => useProfileSettings());
+
+      expect(result.current.loading).toBe(false);
+      expect(typeof result.current.updateProfile).toBe('function');
+      expect(typeof result.current.deleteAccount).toBe('function');
+    });
+  });
+
+  describe('updateProfile', () => {
+    it('updates profile successfully', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      const updatedUser: User = {
+        ...mockUser,
+        displayName: 'Updated Name',
+      };
+      mockUpdateProfile.mockResolvedValue(updatedUser);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        displayName: 'Updated Name',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toEqual(updatedUser);
+      expect(mockUpdateProfile).toHaveBeenCalledWith(updateRequest);
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Success',
+        message: 'Profile updated successfully',
+        color: 'green',
+      });
+      expect(result.current.loading).toBe(false);
+    });
+
+    it('updates email successfully', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      const updatedUser: User = {
+        ...mockUser,
+        email: 'newemail@example.com',
+      };
+      mockUpdateProfile.mockResolvedValue(updatedUser);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        email: 'newemail@example.com',
+        currentPassword: 'current123',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toEqual(updatedUser);
+      expect(mockUpdateProfile).toHaveBeenCalledWith(updateRequest);
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Success',
+        message: 'Profile updated successfully',
+        color: 'green',
+      });
+    });
+
+    it('updates password successfully', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockResolvedValue(mockUser);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        currentPassword: 'oldpass123',
+        newPassword: 'newpass456',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toEqual(mockUser);
+      expect(mockUpdateProfile).toHaveBeenCalledWith(updateRequest);
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Success',
+        message: 'Profile updated successfully',
+        color: 'green',
+      });
+    });
+
+    it('updates multiple fields successfully', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      const updatedUser: User = {
+        ...mockUser,
+        displayName: 'New Display Name',
+        email: 'updated@example.com',
+      };
+      mockUpdateProfile.mockResolvedValue(updatedUser);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        displayName: 'New Display Name',
+        email: 'updated@example.com',
+        currentPassword: 'current123',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toEqual(updatedUser);
+      expect(mockUpdateProfile).toHaveBeenCalledWith(updateRequest);
+    });
+
+    it('shows loading state during update', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      let resolveUpdate: (value: User) => void;
+      const updatePromise = new Promise<User>((resolve) => {
+        resolveUpdate = resolve;
+      });
+      mockUpdateProfile.mockReturnValue(updatePromise);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      // Start update
+      act(() => {
+        void result.current.updateProfile({ displayName: 'Test' });
+      });
+
+      // Should be loading
+      expect(result.current.loading).toBe(true);
+
+      // Resolve the promise
+      await act(async () => {
+        if (resolveUpdate) resolveUpdate(mockUser);
+        await updatePromise;
+      });
+
+      // Should no longer be loading
+      expect(result.current.loading).toBe(false);
+    });
+
+    it('handles password errors specifically', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockRejectedValue(
+        new Error('Current password is incorrect')
+      );
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        currentPassword: 'wrongpass',
+        newPassword: 'newpass123',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toBeNull();
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Current password is incorrect',
+        color: 'red',
+      });
+      expect(result.current.loading).toBe(false);
+    });
+
+    it('handles email errors specifically', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockRejectedValue(new Error('Email already exists'));
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        email: 'existing@example.com',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toBeNull();
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Email is already in use',
+        color: 'red',
+      });
+    });
+
+    it('handles generic update errors', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockRejectedValue(new Error('Server error'));
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {
+        displayName: 'Test Name',
+      };
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toBeNull();
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Failed to update profile',
+        color: 'red',
+      });
+    });
+
+    it('handles non-Error rejection', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockRejectedValue('String error');
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile({
+          displayName: 'Test',
+        });
+      });
+
+      expect(returnedUser).toBeNull();
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Failed to update profile',
+        color: 'red',
+      });
+    });
+  });
+
+  describe('deleteAccount', () => {
+    it('deletes account successfully', async () => {
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+      mockDeleteUser.mockResolvedValue(undefined);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let deleteResult: boolean | undefined;
+      await act(async () => {
+        deleteResult = await result.current.deleteAccount('password123');
+      });
+
+      expect(deleteResult).toBe(true);
+      expect(mockDeleteUser).toHaveBeenCalledWith('password123');
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Success',
+        message: 'Account deleted successfully',
+        color: 'green',
+      });
+      expect(result.current.loading).toBe(false);
+    });
+
+    it('shows loading state during deletion', async () => {
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+      let resolveDelete: () => void;
+      const deletePromise = new Promise<void>((resolve) => {
+        resolveDelete = resolve;
+      });
+      mockDeleteUser.mockReturnValue(deletePromise);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      // Start deletion
+      act(() => {
+        void result.current.deleteAccount('password123');
+      });
+
+      // Should be loading
+      expect(result.current.loading).toBe(true);
+
+      // Resolve the promise
+      await act(async () => {
+        if (resolveDelete) resolveDelete();
+        await deletePromise;
+      });
+
+      // Should no longer be loading
+      expect(result.current.loading).toBe(false);
+    });
+
+    it('handles delete errors with error message', async () => {
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+      mockDeleteUser.mockRejectedValue(new Error('Invalid password'));
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let deleteResult: boolean | undefined;
+      await act(async () => {
+        deleteResult = await result.current.deleteAccount('wrongpass');
+      });
+
+      expect(deleteResult).toBe(false);
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Invalid password',
+        color: 'red',
+      });
+      expect(result.current.loading).toBe(false);
+    });
+
+    it('handles generic delete errors', async () => {
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+      mockDeleteUser.mockRejectedValue(new Error('Server error'));
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let deleteResult: boolean | undefined;
+      await act(async () => {
+        deleteResult = await result.current.deleteAccount('password123');
+      });
+
+      expect(deleteResult).toBe(false);
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Server error',
+        color: 'red',
+      });
+    });
+
+    it('handles non-Error rejection in delete', async () => {
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+      mockDeleteUser.mockRejectedValue('String error');
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let deleteResult: boolean | undefined;
+      await act(async () => {
+        deleteResult = await result.current.deleteAccount('password123');
+      });
+
+      expect(deleteResult).toBe(false);
+      expect(notifications.show).toHaveBeenCalledWith({
+        title: 'Error',
+        message: 'Failed to delete account',
+        color: 'red',
+      });
+    });
+
+    it('handles empty password', async () => {
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+      mockDeleteUser.mockResolvedValue(undefined);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let deleteResult: boolean | undefined;
+      await act(async () => {
+        deleteResult = await result.current.deleteAccount('');
+      });
+
+      expect(deleteResult).toBe(true);
+      expect(mockDeleteUser).toHaveBeenCalledWith('');
+    });
+  });
+
+  describe('concurrent operations', () => {
+    it('handles concurrent profile updates', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile
+        .mockResolvedValueOnce({ ...mockUser, displayName: 'Name 1' })
+        .mockResolvedValueOnce({ ...mockUser, displayName: 'Name 2' });
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let results: (User | null)[] = [];
+      await act(async () => {
+        const promises = [
+          result.current.updateProfile({ displayName: 'Name 1' }),
+          result.current.updateProfile({ displayName: 'Name 2' }),
+        ];
+        results = await Promise.all(promises);
+      });
+
+      expect(results).toHaveLength(2);
+      expect(results[0]?.displayName).toBe('Name 1');
+      expect(results[1]?.displayName).toBe('Name 2');
+      expect(mockUpdateProfile).toHaveBeenCalledTimes(2);
+    });
+
+    it('handles update followed by delete', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      const mockDeleteUser = vi.mocked(userApi.deleteUser);
+
+      mockUpdateProfile.mockResolvedValue(mockUser);
+      mockDeleteUser.mockResolvedValue(undefined);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let updateResult: User | null = null;
+      let deleteResult: boolean | undefined;
+
+      await act(async () => {
+        updateResult = await result.current.updateProfile({
+          displayName: 'Updated',
+        });
+      });
+
+      await act(async () => {
+        deleteResult = await result.current.deleteAccount('password123');
+      });
+
+      expect(updateResult).toEqual(mockUser);
+      expect(deleteResult).toBe(true);
+      expect(mockUpdateProfile).toHaveBeenCalledWith({
+        displayName: 'Updated',
+      });
+      expect(mockDeleteUser).toHaveBeenCalledWith('password123');
+    });
+  });
+
+  describe('hook interface', () => {
+    it('returns correct interface', () => {
+      const { result } = renderHook(() => useProfileSettings());
+
+      expect(typeof result.current.loading).toBe('boolean');
+      expect(typeof result.current.updateProfile).toBe('function');
+      expect(typeof result.current.deleteAccount).toBe('function');
+    });
+
+    it('functions are stable across re-renders', () => {
+      const { result, rerender } = renderHook(() => useProfileSettings());
+
+      const initialFunctions = {
+        updateProfile: result.current.updateProfile,
+        deleteAccount: result.current.deleteAccount,
+      };
+
+      rerender();
+
+      expect(result.current.updateProfile).toBe(initialFunctions.updateProfile);
+      expect(result.current.deleteAccount).toBe(initialFunctions.deleteAccount);
+    });
+  });
+
+  describe('edge cases', () => {
+    it('handles empty update request', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockResolvedValue(mockUser);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile({});
+      });
+
+      expect(returnedUser).toEqual(mockUser);
+      expect(mockUpdateProfile).toHaveBeenCalledWith({});
+    });
+
+    it('handles update with undefined values', async () => {
+      const mockUpdateProfile = vi.mocked(userApi.updateProfile);
+      mockUpdateProfile.mockResolvedValue(mockUser);
+
+      const { result } = renderHook(() => useProfileSettings());
+
+      const updateRequest: UpdateProfileRequest = {};
+
+      let returnedUser: User | null = null;
+      await act(async () => {
+        returnedUser = await result.current.updateProfile(updateRequest);
+      });
+
+      expect(returnedUser).toEqual(mockUser);
+      expect(mockUpdateProfile).toHaveBeenCalledWith(updateRequest);
+    });
+  });
+});