István Szívós Jr. (born 24 April 1948) is a retired Hungarian water polo player. He competed in four consecutive Olympics in 1968–1980 and won a medal in each of them. He also won six gold or silver medals at world and European championships and nine national titles. Between 1966 and 1980 he played 308 international matches for Hungary. In 1996 he was inducted to the International Swimming Hall of Fame, one year earlier than his father István Sr., who won Olympic gold medals in water polo in 1952 and 1956.
Szívós graduated from the Medical University in Budapest, where he later worked as a dentist. After retiring from competitions in 1980 he also became a water polo coach and president of Ferencváros club (FTC), and served as a board member of the Hungarian Water Polo Federation.