S-Oil
| Company type | Public | 
|---|---|
| KRX: 010950 | |
| Industry | Oil and gas | 
| Founded | 6 January 1976 | 
| Founder | SsangYong Group National Iranian Oil Company | 
| Headquarters | , | 
| Key people | Anwar A. Al-Hejazi (CEO) | 
| Revenue | US$34.4 billion (2023) | 
| Parent | Saudi Aramco (63.45%) | 
| Website | s-oil | 
S-Oil Corporation (Korean: 에쓰-오일) is a petroleum and refinery company, headquartered in Seoul, South Korea. It was established in 1976 under its original name Iran-Korea petroleum company (Korean: 한이석유). It produces petroleum, petrochemical, and lubricant products. The company was listed as a Fortune Global 500 company in 2009 (Rank 441).
S-Oil's Onsan Refinery in Ulsan, South Korea has a capacity of some 650,000 barrels per day (103,000 m3/d) in 2016.