Arpad Elo, American physicist and chess player (b. 1903)
Arpad Emmerich Elo (born Élő Árpád Imre; August 25, 1903 – November 5, 1992) was a Hungarian American physics professor known for the creation of the Elo rating system for two-player games such as chess. Born in Egyházaskesző, Kingdom of Hungary, he moved to the United States with his parents in 1913.

Elo was a professor of physics at Marquette University in Milwaukee and a chess master. By the 1930s he was the strongest chess player in Milwaukee, then one of the nation's leading chess cities. He won the Wisconsin State Championship eight times, and was the 11th person inducted into the World Chess Hall of Fame.

Elo died in Brookfield, Wisconsin.