| Matjaž Koželj | |
| Fullname: | Matjaž Koželj |
| Club: | Branik Maribor |
| Birth Date: | 12 March 1970 |
| Birth Place: | Maribor, Slovenia, Yugoslavia |
Matjaž Koželj (born 12 March 1970) is a retired swimmer from Slovenia. He competed at the 1992 Summer Olympics in the 100 m and 200 m butterfly events, but did not reach the finals.