| Matias Biljaka | |
| Nationality: | Austrian/Croatian |
| Birth Date: | 20 January 1999 |
| Birth Place: | Vienna, Austria |
| Height: | 199 cm |
| Currentclub: | Jadran Split |
| Years1: | 2017–2022 |
| Clubs1: | Mladost Zagreb |
| Years2: | 2022–2023 |
| Clubs2: | Jug Dubrovnik |
| Years3: | 2023– |
| Clubs3: | Jadran Split |
| Nationalyears1: | 2022– |
| Nationalteam1: | Croatia |
| Show-Medals: | yes |
Matias Biljaka (born 20 January 1999) is an Austrian-born Croatian water polo player. He represented Croatia at the 2024 Summer Olympics.[1]