Vasilis Diamantopoulos (Greek: Βασίλης Διαμαντόπουλος, 15 November 1920 – 5 May 1999) was a Greek actor. He was one of the founders of the Modern Theater and was the first actor to appear live on Greek television in the single act play "Him and his pants" of Iakovos Kambanellis in 1966. His most characteristic role was that of the austere professor in Giannis Dalianidis' movie Law 4000 and later in shorts including Ekmek Ice Cream in private TV.