Standard Oil of Ohio or Sohio was an American oil company that was acquired by British Petroleum, now part of BP.

It was one of the successor companies to Standard Oil after the anti-trust breakup in 1911. Standard Oil of Ohio was the original Standard Oil company founded by John D. Rockefeller.

BP took majority ownership of the company in the 1970s in return for its share of the Prudhow Bay oilfield in Alaska.In 1987,after all other Standard Oil descendants had ceased use of the name Standard,Standard of Ohio,proud to be the original,sought to corporately rebrand itself under the Standard name while continuing to use the Sohio brand and others to sell gas.However,the next year BP bought out the minority interest and absorbed the Standard brands,Sohio being the last to go in 1991.

When BP merged with Amoco,its American headquarters moved from the former Standard Oil building on Public Square in Cleveland, Ohio to Chicago.