diff --git a/backend/app/models/user.py b/backend/app/models/user.py
new file mode 100644
index 0000000..a43a8bd
--- /dev/null
+++ b/backend/app/models/user.py
@@ -0,0 +1,21 @@
+"""User model."""
+from sqlalchemy import Column, Integer, String, DateTime
+from sqlalchemy.orm import relationship
+from datetime import datetime
+from app.database import Base
+
+class User(Base):
+    """User model."""
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+    email = Column(String(255), unique=True, index=True, nullable=False)
+    username = Column(String(100), unique=True, index=True, nullable=False)
+    hashed_password = Column(String(255), nullable=False)
+    full_name = Column(String(255))
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+    is_active = Column(Integer, default=1)
+
+    workspaces = relationship("Workspace", back_populates="owner")
+    comments = relationship("Comment", back_populates="author")