Manager Dave Trembley said before Saturday's game at Toronto that the operation was on Friday. Hill is expected to resume throwing by spring training.
He went on the disabled list for the second time on July 29 with what the Orioles called "left shoulder inflammation." At the time, Hill said he'd been pitching with a torn labrum.
Hill first went on the DL March 29, returning May 16. He was 3-3 with a 7.80 ERA in 14 games.
The five-year veteran joined the Orioles in a February trade with the Chicago Cubs in exchange for a player to be named.