William James Riley
- Bats Right, Throws Right
- Height 5' 10", Weight 160 lb.
"Pigtail" Billy Riley is remembered for getting the only walk received by the 1875 Keokuk Westerns, who went 1-12.
Riley also played 43 games for the 1879 Cleveland Blues, for whom he was the most-used left fielder.
David Nemec's The Beer and Whisky League has a photo of the 1879 Indianapolis Hoosiers, in which Riley is included. Nemec says that Riley was an early American Association umpire, and that he got the nickname because he looked somewhat Asian.