diff --git a/backend/app/alembic/versions/8725df286943_unique_constraint_on_project_name_and_.py b/backend/app/alembic/versions/8725df286943_unique_constraint_on_project_name_and_.py
new file mode 100644
index 00000000..342751fb
--- /dev/null
+++ b/backend/app/alembic/versions/8725df286943_unique_constraint_on_project_name_and_.py
@@ -0,0 +1,31 @@
+"""unique constraint on project_name and org id
+
+Revision ID: 8725df286943
+Revises: 38f0e8c8dc92
+Create Date: 2025-08-27 12:22:36.633904
+
+"""
+from alembic import op
+import sqlalchemy as sa
+import sqlmodel.sql.sqltypes
+
+
+# revision identifiers, used by Alembic.
+revision = "8725df286943"
+down_revision = "38f0e8c8dc92"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_unique_constraint(
+        "uq_project_name_org_id", "project", ["name", "organization_id"]
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint("uq_project_name_org_id", "project", type_="unique")
+    # ### end Alembic commands ###
diff --git a/backend/app/crud/project.py b/backend/app/crud/project.py
index 9c7e7153..a876ae03 100644
--- a/backend/app/crud/project.py
+++ b/backend/app/crud/project.py
@@ -11,6 +11,17 @@
 
 
 def create_project(*, session: Session, project_create: ProjectCreate) -> Project:
+    project = get_project_by_name(
+        session=session,
+        organization_id=project_create.organization_id,
+        project_name=project_create.name,
+    )
+    if project:
+        logger.error(
+            f"[create_project] Project already exists | 'project_id': {project.id}, 'name': {project.name}"
+        )
+        raise HTTPException(409, "Project already exists")
+
     db_project = Project.model_validate(project_create)
     db_project.inserted_at = now()
     db_project.updated_at = now()
diff --git a/backend/app/models/onboarding.py b/backend/app/models/onboarding.py
index 3b35896a..49214067 100644
--- a/backend/app/models/onboarding.py
+++ b/backend/app/models/onboarding.py
@@ -29,7 +29,7 @@ class OnboardingRequest(SQLModel):
     )
     project_name: str = Field(
         description="Name of the project under the organization",
-        min_length=3,
+        min_length=1,
         max_length=100,
     )
     email: EmailStr | None = Field(
diff --git a/backend/app/models/project.py b/backend/app/models/project.py
index 442b740a..43c0012e 100644
--- a/backend/app/models/project.py
+++ b/backend/app/models/project.py
@@ -1,6 +1,6 @@
 from datetime import datetime
 from typing import Optional, List
-from sqlmodel import Field, Relationship, SQLModel
+from sqlmodel import Field, Relationship, SQLModel, UniqueConstraint
 
 from app.core.util import now
 
@@ -26,6 +26,10 @@ class ProjectUpdate(SQLModel):
 
 # Database model for Project
 class Project(ProjectBase, table=True):
+    __table_args__ = (
+        UniqueConstraint("name", "organization_id", name="uq_project_name_org_id"),
+    )
+
     id: int = Field(default=None, primary_key=True)
     organization_id: int = Field(
         foreign_key="organization.id", index=True, nullable=False, ondelete="CASCADE"
diff --git a/backend/app/tests/crud/test_project.py b/backend/app/tests/crud/test_project.py
index 06aa38ac..9698b466 100644
--- a/backend/app/tests/crud/test_project.py
+++ b/backend/app/tests/crud/test_project.py
@@ -34,6 +34,22 @@ def test_create_project(db: Session) -> None:
     assert project.organization_id == organization.id
 
 
+def test_create_project_duplicate_name(db: Session) -> None:
+    """Test creating a project with a duplicate name."""
+    organization = create_test_organization(db)
+
+    project_name = random_lower_string()
+    project_data = ProjectCreate(
+        name=project_name,
+        description="Test description",
+        is_active=True,
+        organization_id=organization.id,
+    )
+    project = create_project(session=db, project_create=project_data)
+    with pytest.raises(HTTPException, match="Project already exists"):
+        create_project(session=db, project_create=project_data)
+
+
 def test_get_project_by_id(db: Session) -> None:
     """Test retrieving a project by ID."""
     project = create_test_project(db)