Arthur Grant Mills (March 2, 1903 – July 23, 1975) was an American professional baseball player and coach. A right-handed pitcher, Mills worked in 19 games for the 1927–28 Boston Braves, and later spent five full seasons (1944–48) as a coach for the Detroit Tigers of Major League Baseball. Mills was the sole member of manager Steve O'Neill's coaching staff for the 1945 world champion Tigers. He also spent 13 seasons in the minors as a player and coach. Mills died on July 23, 1975, in Utica. He is buried at Forest Hill Cemetery in Utica.