Viscount Masatoshi Okochi (?????, Okochi Masatoshi) (December 6, 1878 – August 29, 1952) was a Japanese physicist and business executive.
He was the third director of the Riken Institute, a position which he assumed in 1921 and held for 25 years.
During this period, he was notable for establishing the Riken Konzern, a zaibatsu of companies which focused on utilizing Riken's research results to produce commercial products.