John Henry Slappey
- Bats Left, Throws Left
- Height 6' 4", Weight 170 lb.
- School University of Georgia
- Debut August 23, 1920
- Final Game October 2, 1920
- Born August 8, 1898 in Albany, GA USA
- Died June 10, 1957 in Marietta, GA USA
John Slappey pitched three games for the 1920 Philadelphia Athletics.
John pitched in the minors from 1921-27, mostly in Southern leagues. He spent much of 1926 with the minor league Baltimore Orioles, where he was a year older than fellow pitcher George Earnshaw and a year younger than fellow pitcher Jack Ogden.