Jackson Milliman Keefer (May 1, 1900 – August 3, 1966) was an American professional football and baseball player.

Keefer attended Steele High School in Dayton, Ohio before enrolling at the University of Michigan.

[4][5][6][7] He later played professional football for the Providence Steam Roller in 1926 and the Dayton Triangles in 1928.

[8] Keefer also played professional baseball for Springfield in the Eastern League in 1927.

[10] Keefer died in 1966 at age 66 at a Veterans Administration hospital in Dayton, Ohio.