Born in Sacramento, California, Gedeon started his professional baseball career in 1912 in the Pacific Coast League.

He was an above-average defensive player, leading all American League second basemen in assists once (1918) and fielding percentage twice (1918 and 1919).

Gedeon – who was a friend of Black Sox conspirator Swede Risberg – was present during a meeting with gamblers, as they were discussing the plot to fix the 1919 World Series.

On November 3, 1921, Gedeon was banned for life from organized baseball for "having guilty knowledge" of the Black Sox Scandal.

His nephew, Elmer Gedeon, was one of only two Major League Baseball players to be killed in World War II, dying in 1944.