diff --git a/Makefile b/Makefile
index 96ce1c9..09ab0d0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: setup docker-up docker-down db-init load-data run test dbt-run dbt-test lint format ci deploy clean help logs run-detached etl-toronto
+.PHONY: setup docker-up docker-down db-init load-data seed-amenities run test dbt-run dbt-test lint format ci deploy clean help logs run-detached etl-toronto
 
 # Default target
 .DEFAULT_GOAL := help
@@ -87,6 +87,10 @@ load-data-only: ## Load Toronto data without running dbt
 	@echo "$(GREEN)Loading Toronto data (skip dbt)...$(NC)"
 	$(PYTHON) scripts/data/load_toronto_data.py --skip-dbt
 
+seed-amenities: ## Seed sample amenity data (run after load-data)
+	@echo "$(GREEN)Seeding amenity data...$(NC)"
+	$(PYTHON) scripts/data/seed_amenity_data.py
+
 # =============================================================================
 # Application
 # =============================================================================
diff --git a/scripts/data/seed_amenity_data.py b/scripts/data/seed_amenity_data.py
new file mode 100644
index 0000000..1cf6a5b
--- /dev/null
+++ b/scripts/data/seed_amenity_data.py
@@ -0,0 +1,153 @@
+#!/usr/bin/env python3
+"""Seed sample amenity data for development/testing.
+
+This script populates fact_amenities with sample data and updates
+dim_neighbourhood with population from fact_census, then runs dbt
+to rebuild the marts.
+
+Usage:
+    python scripts/data/seed_amenity_data.py
+
+Run this after load_toronto_data.py if amenity data is missing.
+"""
+
+import os
+import random
+import subprocess
+import sys
+from pathlib import Path
+
+from dotenv import load_dotenv
+from sqlalchemy import create_engine, text
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+load_dotenv(PROJECT_ROOT / ".env")
+
+DATABASE_URL = os.environ.get("DATABASE_URL")
+if not DATABASE_URL:
+    print("ERROR: DATABASE_URL not set in .env")
+    sys.exit(1)
+
+
+def seed_amenities() -> int:
+    """Insert sample amenity data for all neighbourhoods."""
+    engine = create_engine(DATABASE_URL)
+
+    with engine.connect() as conn:
+        result = conn.execute(
+            text("SELECT neighbourhood_id FROM public.dim_neighbourhood")
+        )
+        neighbourhood_ids = [row[0] for row in result]
+
+    print(f"Found {len(neighbourhood_ids)} neighbourhoods")
+
+    amenity_types = [
+        "Parks",
+        "Schools",
+        "Transit Stops",
+        "Libraries",
+        "Community Centres",
+        "Recreation",
+    ]
+    year = 2024
+
+    with engine.begin() as conn:
+        conn.execute(text("DELETE FROM public.fact_amenities"))
+
+        total = 0
+        for n_id in neighbourhood_ids:
+            for amenity_type in amenity_types:
+                count = random.randint(1, 50)
+                conn.execute(
+                    text(
+                        """
+                    INSERT INTO public.fact_amenities
+                    (neighbourhood_id, amenity_type, count, year)
+                    VALUES (:neighbourhood_id, :amenity_type, :count, :year)
+                """
+                    ),
+                    {
+                        "neighbourhood_id": n_id,
+                        "amenity_type": amenity_type,
+                        "count": count,
+                        "year": year,
+                    },
+                )
+                total += 1
+
+    print(f"Inserted {total} amenity records")
+    return total
+
+
+def update_population() -> int:
+    """Update dim_neighbourhood with population from fact_census."""
+    engine = create_engine(DATABASE_URL)
+
+    with engine.begin() as conn:
+        result = conn.execute(
+            text(
+                """
+            UPDATE public.dim_neighbourhood dn
+            SET population = fc.population
+            FROM public.fact_census fc
+            WHERE dn.neighbourhood_id = fc.neighbourhood_id
+              AND fc.census_year = 2021
+        """
+            )
+        )
+        count = int(result.rowcount)
+
+    print(f"Updated {count} neighbourhoods with population")
+    return count
+
+
+def run_dbt() -> bool:
+    """Run dbt to rebuild amenity marts."""
+    dbt_dir = PROJECT_ROOT / "dbt"
+    venv_dbt = PROJECT_ROOT / ".venv" / "bin" / "dbt"
+    dbt_cmd = str(venv_dbt) if venv_dbt.exists() else "dbt"
+
+    print("Running dbt to rebuild marts...")
+
+    env = os.environ.copy()
+
+    result = subprocess.run(
+        [
+            dbt_cmd,
+            "run",
+            "--profiles-dir",
+            str(dbt_dir),
+            "--select",
+            "+mart_neighbourhood_amenities",
+        ],
+        cwd=dbt_dir,
+        capture_output=True,
+        text=True,
+        env=env,
+    )
+
+    if result.returncode != 0:
+        print(f"dbt failed:\n{result.stdout}\n{result.stderr}")
+        return False
+
+    print("dbt completed successfully")
+    return True
+
+
+def main() -> int:
+    """Main entry point."""
+    print("Seeding amenity data...")
+
+    seed_amenities()
+    update_population()
+
+    if not run_dbt():
+        return 1
+
+    print("\nDone! Amenity data is ready.")
+    return 0
+
+
+if __name__ == "__main__":
+    result = main()
+    sys.exit(result)