| Mattias Ohlin | |
| Fullname: | Rolf Lennart Mattias Ohlin |
| Nationality: | Swedish |
| Sport: | freestyle swimming and backstroke swimming |
| Club: | Trelleborgs SS |
| Birth Date: | 4 February 1978 |
| Birth Place: | Trelleborg, Sweden |
Mattias Ohlin (born 4 February 1978) is a former international freestyle and backstroke swimmer from Sweden,[1] who participated in two consecutive Summer Olympics for his native country, starting in 2000.
Ohlin is best known for winning the gold medal in the men's 4×100 m freestyle at the 2000 FINA Short Course World Championships in Athens, Greece.