Frank Joseph Corridon [Fiddler] (November 25, 1880 – February 21, 1941) was an American pitcher in Major League Baseball who played for three teams between the 1904 and 1910 seasons. Listed at 6 ft 0 in (1.83 m) 170 lb., Corridon was a switch-hitter and threw right-handed. He was born in Newport, Rhode Island.
Corridon entered the majors in 1904 with the Chicago Cubs, appearing for them in 24 games before joining the Philadelphia Phillies (1904–1905, 1907–1909) and St. Louis Cardinals (1910). His most productive season came with the 1907 Phillies, when he posted career-numbers in wins (18), starts (32), complete games (23) and innings pitched (274.0), while collecting a 2.46 ERA. He finished 14–10 with a 2.51 ERA the next season, and went 11–7 with a career-high 2.11 in 1909. He faded to 6–14 with the Cardinals in 1910, his last major league season.
In a six-year career, Corridon posted a 70–67 record with a 2.80 ERA in 180 appearances, including 140 starts, 99 complete games, 10 shutouts, seven saves and 1216.0 innings of work, posting a 1.22 strikeout-to-walk ratio (458-to-375). He is widely recognized as the inventor of the "Spitball" in the early 1900's.
Corridon died at the age of 60 in Syracuse, New York.