Vadim Ivanovich Utkin (Russian: Вадим Иванович Уткин; 30 October 1937 – 18 September 2022) was a Russian-American control theorist, electrical engineer and a professor of Electrical Engineering and Mechanical Engineering at the Ohio State University. He is best known for being one of the originators of Sliding Mode Control and Variable Structure Systems, which have become fundamental concepts in the field of nonlinear control (e.g. robust control).