Stillman Witt (January 4, 1808 — April 29, 1875) was an American railroad and steel industry executive best known for building the Cleveland, Columbus and Cincinnati Railroad, Cleveland, Painesville and Ashtabula Railroad, and the Bellefontaine and Indiana Railroad. Through his banking activities, he played a significant role in the early years of the Standard Oil company. He was also one of the founding investors in the Cleveland Rolling Mill, a major steel firm in the United States.