Cosmo Oil Corporation
- Country: Japan
- Type: Commercial
- Website: www.cosmo-oil.co.jp
- Update: 05-02
Cosmo Oil Corporation (Cosmo Oil) is a Japanese oil company founded in 1986 and headquartered in Tokyo. Cosmo Oil owns four refineries in Ichihara, Yokkaichi, Sakaide, and Sakai, Japan. Kosmo Oil was ranked 345th in the 2013 Fortune 500 ranking.