James Blaine "Rifle Jim" Middleton (May 28, 1889 – January 12, 1974) was a professional baseball player. He was a right-handed pitcher over parts of two seasons (1917, 1921) with the New York Giants and Detroit Tigers. For his career, he compiled a 7–12 record in 51 appearances, with a 4.51 earned run average and 40 strikeouts.
He was born and later died in Argos, Indiana, at the age of 84.