S-Oil is a South Korean oil refining and marketing company.

Aramco Overseas holds 63.4 per cent of the common stock with the remaining shares traded on the Korean Stock Exchange. It is also listed on the Dow Jones Index.

S-Oil owns and operates an integrated refining lubricants and aromatic-type petrochemicals complex in Ulsan, on the southeast coast of the Korean peninsula. It runs at 669,000 barrels per day.

The company markets petroleum products and petrochemicals in Korea through a nationwide distribution and marketing network that includes seven product distribution terminals and over 1,600 branded retail service stations.