10. Amoco Cadiz Oil Tankers – 1.6 to 1.7 Million Barrels

9. The Castillo De Bellver – 1.85 Million Barrels

8. ABT Summer – 1.8 to 1.9 Million Barrels

7. Iran-Iraq War – 1.9 Million Barrels

6. Fergana Valley – 2+ Million Barrels

5. The Atlantic Empress – 2.1 to 2.4 Million Barrels

4. Ixtoc – 3+ Million Barrels

3. BP Oil Spill – 4.7 to 4.9 Million Barrels

2. The Gulf War Oil Spill – 8 Million Barrels

1. The Midway-Sunset Oil Field – Lakeview Gusher – 9 Million Barrels