As of September 2026 Marathon Petroleum has a market cap of A$146.15 Billion. This makes Marathon Petroleum the world's 223th most valuable company by market cap according to our data. The market capitalization, commonly called market cap, is the total market value of a publicly traded company's outstanding shares and is commonly used to measure how much a company is worth.
On Aug 31st, 2026 the market cap of Marathon Petroleum was reported to be: