| Matias Viazzo | |
| Birth Name: | Matias Viazzo |
| Birth Date: | 6 March 1983 |
| Birth Place: | Argentina |
| Ru Position: | Wing/Centre |
| Youthyears1: | |
| Years1: | |
| Clubs1: | Bourgoin |
| Superyears1: | |
| Repyears1: | |
| Repteam1: | Argentina |
| Ru Sevensnationalyears1: | |
Matias Viazzo (born March 6, 1983) is an Argentine rugby union footballer who plays at wing and centre where he has represented the Argentina national rugby union team. He currently plays for club Bourgoin.