diff --git a/apps/server/src/entities/class-student.entity.ts b/apps/server/src/entities/class-student.entity.ts
new file mode 100644
index 0000000..4b9906c
--- /dev/null
+++ b/apps/server/src/entities/class-student.entity.ts
@@ -0,0 +1,47 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  CreateDateColumn,
+  ManyToOne,
+  JoinColumn,
+  Unique,
+} from 'typeorm';
+import { Class } from './class.entity';
+import { Student } from './student.entity';
+
+@Entity('class_student')
+@Unique(['classId', 'studentId'])
+export class ClassStudent {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Column({ name: 'class_id', type: 'integer' })
+  classId: number;
+
+  @ManyToOne(() => Class, { onDelete: 'CASCADE' })
+  @JoinColumn({ name: 'class_id' })
+  class: Class;
+
+  @Column({ name: 'student_id', type: 'integer' })
+  studentId: number;
+
+  @ManyToOne(() => Student)
+  @JoinColumn({ name: 'student_id' })
+  student: Student;
+
+  @Column({ name: 'enrollment_id', type: 'integer', nullable: true })
+  enrollmentId: number;
+
+  @Column({ name: 'join_date', type: 'date', nullable: true })
+  joinDate: string;
+
+  @Column({ name: 'leave_date', type: 'date', nullable: true })
+  leaveDate: string;
+
+  @Column({ name: 'status', length: 10, default: 'active' })
+  status: string;
+
+  @CreateDateColumn({ name: 'created_at' })
+  createdAt: Date;
+}
diff --git a/apps/server/src/entities/class-teacher.entity.ts b/apps/server/src/entities/class-teacher.entity.ts
new file mode 100644
index 0000000..6b36c12
--- /dev/null
+++ b/apps/server/src/entities/class-teacher.entity.ts
@@ -0,0 +1,48 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  CreateDateColumn,
+  ManyToOne,
+  JoinColumn,
+  Unique,
+} from 'typeorm';
+import { Class } from './class.entity';
+import { User } from './user.entity';
+
+export enum TeacherRoleType {
+  SUBJECT_TEACHER = 'subject_teacher',
+  HEAD_TEACHER = 'head_teacher',
+  LIFE_TEACHER = 'life_teacher',
+  ACADEMIC_TEACHER = 'academic_teacher',
+}
+
+@Entity('class_teacher')
+@Unique(['classId', 'userId', 'roleType'])
+export class ClassTeacher {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Column({ name: 'class_id', type: 'integer' })
+  classId: number;
+
+  @ManyToOne(() => Class, { onDelete: 'CASCADE' })
+  @JoinColumn({ name: 'class_id' })
+  class: Class;
+
+  @Column({ name: 'user_id', type: 'integer' })
+  userId: number;
+
+  @ManyToOne(() => User)
+  @JoinColumn({ name: 'user_id' })
+  user: User;
+
+  @Column({ name: 'role_type', length: 30 })
+  roleType: string;
+
+  @Column({ name: 'subject', length: 50, nullable: true })
+  subject: string;
+
+  @CreateDateColumn({ name: 'created_at' })
+  createdAt: Date;
+}
diff --git a/apps/server/src/entities/class.entity.ts b/apps/server/src/entities/class.entity.ts
new file mode 100644
index 0000000..5bfe35a
--- /dev/null
+++ b/apps/server/src/entities/class.entity.ts
@@ -0,0 +1,76 @@
+import {
+  Entity,
+  PrimaryGeneratedColumn,
+  Column,
+  CreateDateColumn,
+  UpdateDateColumn,
+  ManyToOne,
+  JoinColumn,
+} from 'typeorm';
+
+export enum ClassType {
+  CULTURE = 'culture',
+  PROFESSIONAL = 'professional',
+  BOOTCAMP = 'bootcamp',
+  SPRINT = 'sprint',
+}
+
+export enum ClassStatus {
+  ENROLLING = 'enrolling',
+  ACTIVE = 'active',
+  ENDED = 'ended',
+  SUSPENDED = 'suspended',
+}
+
+@Entity('classes')
+export class Class {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Column({ name: 'name', length: 100 })
+  name: string;
+
+  @Column({ name: 'code', length: 50, unique: true })
+  code: string;
+
+  @Column({ name: 'department_id', type: 'integer', nullable: true })
+  departmentId: number;
+
+  // Forward reference — Department entity will be added later
+  @ManyToOne('Department', { nullable: true })
+  @JoinColumn({ name: 'department_id' })
+  department: unknown;
+
+  @Column({ name: 'class_type', length: 20 })
+  classType: string;
+
+  @Column({ name: 'start_date', type: 'date', nullable: true })
+  startDate: string;
+
+  @Column({ name: 'end_date', type: 'date', nullable: true })
+  endDate: string;
+
+  @Column({ name: 'status', length: 20, default: ClassStatus.ENROLLING })
+  status: string;
+
+  @Column({ name: 'head_teacher_id', type: 'integer', nullable: true })
+  headTeacherId: number;
+
+  @Column({ name: 'life_teacher_id', type: 'integer', nullable: true })
+  lifeTeacherId: number;
+
+  @Column({ name: 'academic_teacher_id', type: 'integer', nullable: true })
+  academicTeacherId: number;
+
+  @Column({ name: 'max_students', type: 'integer', default: 0 })
+  maxStudents: number;
+
+  @Column({ name: 'notes', type: 'text', nullable: true })
+  notes: string;
+
+  @CreateDateColumn({ name: 'created_at' })
+  createdAt: Date;
+
+  @UpdateDateColumn({ name: 'updated_at' })
+  updatedAt: Date;
+}
diff --git a/apps/server/src/entities/index.ts b/apps/server/src/entities/index.ts
index 7f1fdc6..872b79f 100644
--- a/apps/server/src/entities/index.ts
+++ b/apps/server/src/entities/index.ts
@@ -13,3 +13,6 @@ export { Tenant } from './tenant.entity';
 export { ClassroomRental } from './classroom-rental.entity';
 export { Permission } from './permission.entity';
 export { Role } from './role.entity';
+export { Class, ClassType, ClassStatus } from './class.entity';
+export { ClassStudent } from './class-student.entity';
+export { ClassTeacher, TeacherRoleType } from './class-teacher.entity';