Louis Wood Mahaffey ((1874-01-03)January 3, 1874 – (1949-10-26)October 26, 1949) was a Major League Baseball pitcher who played one season with the Louisville Colonels.

In his only game with the Louisville Colonels of the National League in 1898, Mahaffey took the loss surrendering three earned runs in nine full innings pitched.

A few weeks into the season he was forced to change his position from pitcher to first base by manager Jack Grim.

Mahaffey claimed other league umpires received $50 to $100 more and was quoted by the Morning Oregonian as saying, "I have never yet worked for less than the other fellows and it's too late to begin now.

[1] In November 1913 Mahaffey's wife went to the San Francisco Police Department to report her husband had abandoned her without material support.