Frank Blaine Withrow (June 14, 1891 – September 5, 1966), nicknamed "Kid", was a professional baseball player. He played two seasons, 1920 and 1922, in Major League Baseball for the Philadelphia Phillies, primarily as a catcher. In 58 games, Withrow had 31 hits in 153 at bats, for a .203 batting average. He batted and threw right-handed.

Withrow was born in Greenwood, Missouri, and died in Omaha, Nebraska.