The Waterloo Diamonds was a baseball team located in Waterloo, Iowa that formed in 1989 and lasted until 1993. A member of the Midwest League, they were affiliated with two teams in 1989, the Baltimore Orioles and San Diego Padres, and the franchise was a descendant of the Waterloo Hawks. From 1990 to 1993, they were affiliated solely with the Padres. Their stadium was Riverfront Stadium.
| Year | Record | Finish | Manager | Playoffs |
|---|---|---|---|---|
| 1989 | 47-89 | 14th | Jaime Moreno | |
| 1990 | 60-76 | 11th | Bryan Little | |
| 1991 | 75-63 | 4th | Bryan Little | |
| 1992 | 59-78 | 12th | Keith Champion | |
| 1993 | 54-79 | 13th | Ed Romero |