István Gulyás (Hungarian: Gulyás István; born October 13, 1931 in Pécs, Hungary - died July 31, 2000 in Budapest) was the second Hungarian tennis player to become a Grand Slam finalist. He was defeated in the 1966 French Open Men's Final by Tony Roche of Australia (6–1, 6–4, 7–5), after allowing the match to be delayed 24 hours to allow Roche to recover from an ankle injury. It was Gulyas' lone Grand Slam final, though he made the semi-finals of the tournament the following year (and the quarter-finals in 1971). He was ranked inside the world's Top 10 on more than one occasion and holds the record for most Hungarian National Championship titles having won it 15 times in his career. Lance Tingay of The Daily Telegraph ranked Gulyás as World No. 8 in 1966.