diff --git a/src/users/user-response.mapper.spec.ts b/src/users/user-response.mapper.spec.ts
new file mode 100644
index 0000000..281b01e
--- /dev/null
+++ b/src/users/user-response.mapper.spec.ts
@@ -0,0 +1,86 @@
+import { toPublicUser } from './user-response.mapper';
+import { User, GithubAccount } from '../common/entities';
+import { UserRole } from '../common/enums';
+
+function makeTestUser(overrides: Partial<User> = {}): User {
+  const user = new User();
+  user.id = 'user-uuid-1';
+  user.username = 'alice';
+  user.email = 'alice@example.com';
+  user.displayName = 'Alice Developer';
+  user.avatarUrl = 'https://avatars.githubusercontent.com/u/123';
+  user.roles = [UserRole.CONTRIBUTOR];
+  user.stellarAddress = 'GA2C5RFPE6GCKMY3Z4AWSDVOMLCUCPW7S55QHGQ7G6EGE2TRD4F4QG';
+  user.createdAt = new Date('2026-01-01T00:00:00Z');
+  user.updatedAt = new Date('2026-01-02T00:00:00Z');
+  user.githubAccount = null;
+  return Object.assign(user, overrides);
+}
+
+describe('UserResponseMapper (toPublicUser)', () => {
+  it('strips email for an unauthenticated or unrelated user request', () => {
+    const user = makeTestUser();
+    const result = toPublicUser(user, {
+      currentUser: { userId: 'different-user-id', roles: [UserRole.CONTRIBUTOR] },
+    });
+
+    expect(result).not.toHaveProperty('email');
+    expect(result.id).toBe('user-uuid-1');
+    expect(result.username).toBe('alice');
+    expect(result.displayName).toBe('Alice Developer');
+    expect(result.stellarAddress).toBe('GA2C5RFPE6GCKMY3Z4AWSDVOMLCUCPW7S55QHGQ7G6EGE2TRD4F4QG');
+  });
+
+  it('strips email when no currentUser is provided', () => {
+    const user = makeTestUser();
+    const result = toPublicUser(user);
+
+    expect(result).not.toHaveProperty('email');
+    expect(result.username).toBe('alice');
+  });
+
+  it('includes email when caller is the owner (same userId)', () => {
+    const user = makeTestUser();
+    const result = toPublicUser(user, {
+      currentUser: { userId: 'user-uuid-1', roles: [UserRole.CONTRIBUTOR] },
+    });
+
+    expect(result.email).toBe('alice@example.com');
+  });
+
+  it('includes email when caller is an admin or maintainer', () => {
+    const user = makeTestUser();
+    const result = toPublicUser(user, {
+      currentUser: { userId: 'admin-user-id', roles: ['admin'] },
+    });
+
+    expect(result.email).toBe('alice@example.com');
+
+    const resultMaintainer = toPublicUser(user, {
+      currentUser: { userId: 'm-user-id', roles: [UserRole.MAINTAINER] },
+    });
+
+    expect(resultMaintainer.email).toBe('alice@example.com');
+  });
+
+  it('safely serializes githubAccount relation without sensitive token properties', () => {
+    const account = new GithubAccount();
+    account.id = 'gh-acc-1';
+    account.githubId = '12345';
+    account.login = 'alice';
+    account.profileUrl = 'https://github.com/alice';
+    account.avatarUrl = 'https://avatars.githubusercontent.com/u/123';
+    account.accessToken = 'gho_secret_token_12345';
+    account.refreshToken = 'ghr_refresh_token_12345';
+    account.createdAt = new Date('2026-01-01T00:00:00Z');
+    account.updatedAt = new Date('2026-01-02T00:00:00Z');
+
+    const user = makeTestUser({ githubAccount: account });
+    const result = toPublicUser(user);
+
+    expect(result.githubAccount).toBeDefined();
+    expect(result.githubAccount?.login).toBe('alice');
+    expect(result.githubAccount).not.toHaveProperty('accessToken');
+    expect(result.githubAccount).not.toHaveProperty('refreshToken');
+  });
+});
diff --git a/src/users/user-response.mapper.ts b/src/users/user-response.mapper.ts
new file mode 100644
index 0000000..5ddcf8b
--- /dev/null
+++ b/src/users/user-response.mapper.ts
@@ -0,0 +1,82 @@
+import { User } from '../common/entities';
+import { UserRole } from '../common/enums';
+
+export interface PublicGithubAccount {
+  id: string;
+  githubId: string;
+  login: string;
+  profileUrl: string | null;
+  avatarUrl: string | null;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+export interface PublicUser {
+  id: string;
+  username: string;
+  displayName: string | null;
+  avatarUrl: string | null;
+  roles: UserRole[];
+  stellarAddress: string | null;
+  email?: string | null;
+  githubAccount?: PublicGithubAccount | null;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+export interface UserSerializationOptions {
+  /**
+   * The authenticated user performing the request (if any).
+   */
+  currentUser?: {
+    userId?: string;
+    roles?: (UserRole | string)[];
+  } | null;
+}
+
+/**
+ * Maps a User entity into a public-safe HTTP response DTO.
+ * Strips sensitive PII (`email`) unless the request caller is the user themselves
+ * or has an admin/maintainer role (or 'admin' role string), mirroring the pattern established in `toPublicEscrow`.
+ */
+export function toPublicUser(
+  user: User,
+  options?: UserSerializationOptions,
+): PublicUser {
+  const isOwner = options?.currentUser?.userId === user.id;
+  const isAdmin =
+    options?.currentUser?.roles?.includes('admin') ||
+    options?.currentUser?.roles?.includes(UserRole.MAINTAINER) ||
+    false;
+  const canViewEmail = isOwner || isAdmin;
+
+  const publicGithubAccount: PublicGithubAccount | null = user.githubAccount
+    ? {
+        id: user.githubAccount.id,
+        githubId: user.githubAccount.githubId,
+        login: user.githubAccount.login,
+        profileUrl: user.githubAccount.profileUrl,
+        avatarUrl: user.githubAccount.avatarUrl,
+        createdAt: user.githubAccount.createdAt,
+        updatedAt: user.githubAccount.updatedAt,
+      }
+    : null;
+
+  const publicUser: PublicUser = {
+    id: user.id,
+    username: user.username,
+    displayName: user.displayName,
+    avatarUrl: user.avatarUrl,
+    roles: user.roles,
+    stellarAddress: user.stellarAddress,
+    createdAt: user.createdAt,
+    updatedAt: user.updatedAt,
+    ...(user.githubAccount !== undefined ? { githubAccount: publicGithubAccount } : {}),
+  };
+
+  if (canViewEmail) {
+    publicUser.email = user.email;
+  }
+
+  return publicUser;
+}
diff --git a/src/users/users.controller.spec.ts b/src/users/users.controller.spec.ts
new file mode 100644
index 0000000..ea1a2a9
--- /dev/null
+++ b/src/users/users.controller.spec.ts
@@ -0,0 +1,94 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { UsersController } from './users.controller';
+import { UsersService } from './users.service';
+import { User } from '../common/entities';
+import { UserRole } from '../common/enums';
+import type { Request } from 'express';
+
+function makeUser(id: string, email: string, username: string): User {
+  const user = new User();
+  user.id = id;
+  user.email = email;
+  user.username = username;
+  user.displayName = username.toUpperCase();
+  user.avatarUrl = null;
+  user.roles = [UserRole.CONTRIBUTOR];
+  user.stellarAddress = 'GSTELLARADDRESS';
+  user.createdAt = new Date('2026-01-01');
+  user.updatedAt = new Date('2026-01-02');
+  user.githubAccount = null;
+  return user;
+}
+
+describe('UsersController (Auth & PII Protection #64)', () => {
+  let controller: UsersController;
+  let usersService: {
+    list: jest.Mock;
+    findById: jest.Mock;
+    setStellarAddress: jest.Mock;
+  };
+
+  const user1 = makeUser('user-1', 'alice@example.com', 'alice');
+  const user2 = makeUser('user-2', 'bob@example.com', 'bob');
+
+  beforeEach(async () => {
+    usersService = {
+      list: jest.fn().mockResolvedValue([user1, user2]),
+      findById: jest.fn().mockImplementation((id: string) => {
+        if (id === 'user-1') return Promise.resolve(user1);
+        if (id === 'user-2') return Promise.resolve(user2);
+        return Promise.reject(new Error('User not found'));
+      }),
+      setStellarAddress: jest.fn().mockResolvedValue(user1),
+    };
+
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [UsersController],
+      providers: [{ provide: UsersService, useValue: usersService }],
+    }).compile();
+
+    controller = module.get(UsersController);
+  });
+
+  describe('GET /users (list)', () => {
+    it('redacts email for users other than the caller', async () => {
+      const req = {
+        user: { userId: 'user-1', username: 'alice', roles: [UserRole.CONTRIBUTOR] },
+      } as unknown as Request;
+
+      const result = await controller.list(req);
+
+      expect(result).toHaveLength(2);
+      // Own user keeps email
+      expect(result[0].id).toBe('user-1');
+      expect(result[0].email).toBe('alice@example.com');
+
+      // Other user has email redacted
+      expect(result[1].id).toBe('user-2');
+      expect(result[1]).not.toHaveProperty('email');
+    });
+  });
+
+  describe('GET /users/:id (findOne)', () => {
+    it('returns email when fetching own profile', async () => {
+      const req = {
+        user: { userId: 'user-1', username: 'alice', roles: [UserRole.CONTRIBUTOR] },
+      } as unknown as Request;
+
+      const result = await controller.findOne('user-1', req);
+      expect(result.id).toBe('user-1');
+      expect(result.email).toBe('alice@example.com');
+    });
+
+    it('redacts email when fetching another user profile', async () => {
+      const req = {
+        user: { userId: 'user-1', username: 'alice', roles: [UserRole.CONTRIBUTOR] },
+      } as unknown as Request;
+
+      const result = await controller.findOne('user-2', req);
+      expect(result.id).toBe('user-2');
+      expect(result).not.toHaveProperty('email');
+      expect(result.username).toBe('bob');
+    });
+  });
+});
diff --git a/src/users/users.controller.ts b/src/users/users.controller.ts
index 37a22bb..923c6fc 100644
--- a/src/users/users.controller.ts
+++ b/src/users/users.controller.ts
@@ -1,36 +1,68 @@
-import { Body, Controller, Get, Param, Patch, UseGuards } from '@nestjs/common';
+import {
+  Body,
+  Controller,
+  Get,
+  Param,
+  Patch,
+  Req,
+  UseGuards,
+} from '@nestjs/common';
 import { ApiBearerAuth, ApiTags } from '@nestjs/swagger';
 import { IsString } from 'class-validator';
+import type { Request } from 'express';
 import { UsersService } from './users.service';
 import { JwtAuthGuard } from '../auth/guards/jwt-auth.guard';
+import { toPublicUser, PublicUser } from './user-response.mapper';
+import { UserRole } from '../common/enums';
 
 class SetStellarAddressDto {
   @IsString()
   stellarAddress: string;
 }
 
+interface AuthenticatedUserPayload {
+  userId: string;
+  username: string;
+  roles?: UserRole[];
+}
+
 @ApiTags('users')
+@ApiBearerAuth()
+@UseGuards(JwtAuthGuard)
 @Controller('users')
 export class UsersController {
   constructor(private readonly usersService: UsersService) {}
 
   @Get()
-  list() {
-    return this.usersService.list();
+  async list(@Req() req: Request): Promise<PublicUser[]> {
+    const userPayload = req.user as AuthenticatedUserPayload | undefined;
+    const users = await this.usersService.list();
+    return users.map((user) =>
+      toPublicUser(user, { currentUser: userPayload }),
+    );
   }
 
   @Get(':id')
-  findOne(@Param('id') id: string) {
-    return this.usersService.findById(id);
+  async findOne(
+    @Param('id') id: string,
+    @Req() req: Request,
+  ): Promise<PublicUser> {
+    const userPayload = req.user as AuthenticatedUserPayload | undefined;
+    const user = await this.usersService.findById(id);
+    return toPublicUser(user, { currentUser: userPayload });
   }
 
-  @ApiBearerAuth()
-  @UseGuards(JwtAuthGuard)
   @Patch(':id/stellar-address')
-  setStellarAddress(
+  async setStellarAddress(
     @Param('id') id: string,
     @Body() dto: SetStellarAddressDto,
-  ) {
-    return this.usersService.setStellarAddress(id, dto.stellarAddress);
+    @Req() req: Request,
+  ): Promise<PublicUser> {
+    const userPayload = req.user as AuthenticatedUserPayload | undefined;
+    const user = await this.usersService.setStellarAddress(
+      id,
+      dto.stellarAddress,
+    );
+    return toPublicUser(user, { currentUser: userPayload });
   }
 }