| Matias Koski | |
| Full Name: | Matias Mikael Ilmari Koski |
| Strokes: | Freestyle |
| Club: | Dynamo Swim Club |
| Collegeteam: | University of Georgia (U.S.) |
| Birth Date: | 18 May 1994 |
| Birth Place: | Hämeenlinna, Finland |
| Height: | 6 ft 5 in |
| Weight: | 205 lb |
Matias Koski (born 18 May 1994) is a Finnish swimmer. At the 2012 Summer Olympics, he competed in the Men's 400 metre freestyle, finishing in 22nd place in the heats. He also competed in the Men's 200 metre freestyle, winning his heat, but finishing in 31st in the heats and the Men's 1500 metre freestyle, finishing in 26th place in the heats.In his colliegate swimming, Matias won the Men's 1650 Freestyle at the NCAA Championship.