diff --git a/backend/app/models/task.py b/backend/app/models/task.py
new file mode 100644
index 0000000..69ceb8c
--- /dev/null
+++ b/backend/app/models/task.py
@@ -0,0 +1,57 @@
+"""Task model."""
+from sqlalchemy import (
+    Column, String, Integer, Text, DateTime, ForeignKey, Boolean, JSON
+)
+from app.models.base import Base, TimestampMixin, TenantMixin
+
+
+class Task(Base, TimestampMixin, TenantMixin):
+    """A task is a work unit within a project.
+
+    Can be assigned to a human user or an AI Worker.
+    Status: pending -> assigned -> in_progress -> review -> done -> rejected -> cancelled
+    Priority: low, medium, high, urgent
+    """
+    __tablename__ = "tasks"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    project_id = Column(Integer, ForeignKey("projects.id"), nullable=False, index=True)
+
+    title = Column(String(500), nullable=False)
+    description = Column(Text, default="")
+    status = Column(String(50), nullable=False, default="pending")
+    priority = Column(String(20), nullable=False, default="medium")
+
+    # Assignment: assignee is a User (human or AI-linked)
+    assignee_id = Column(Integer, ForeignKey("users.id"), nullable=True)
+
+    # If assigned to AI, which worker profile
+    worker_id = Column(Integer, ForeignKey("ai_workers.id"), nullable=True)
+
+    # Task type: single_call, agent_loop, multi_agent (MVP: single_call + agent_loop)
+    task_type = Column(String(50), default="single_call")
+
+    # Task input (prompt, context, parameters)
+    input_data = Column(Text, default="")  # JSON string with prompt/context
+    output_data = Column(Text, nullable=True)  # JSON string with result
+
+    # HITL: does this task require human review?
+    requires_review = Column(Boolean, default=True)
+    review_status = Column(String(50), nullable=True)  # pending, approved, rejected
+
+    # Cost tracking
+    token_cost_estimate = Column(Integer, nullable=True)
+
+    # Dependencies (list of task IDs that must complete first)
+    depends_on = Column(Text, default="[]")  # JSON array
+
+    # Timeline
+    due_date = Column(DateTime, nullable=True)
+    started_at = Column(DateTime, nullable=True)
+    completed_at = Column(DateTime, nullable=True)
+
+    # Execution metadata (retries, duration, etc.)
+    execution_meta = Column(Text, default="{}")  # JSON
+
+    def __repr__(self):
+        return f"<Task {self.title} [{self.status}]>"