| Position: | Power forward / center |
| League: | Slovenian League ABA League |
| Height M: | 2.04 |
| Weight Kg: | 91 |
| Birth Date: | 1996 10, mf=yes |
| Birth Place: | Slovenj Gradec, Slovenia |
| Nationality: | Slovenian |
| Team: | Cedevita Olimpija |
| Number: | 15 |
| Draft Year: | 2018 |
| Career Start: | 2013 |
| Years1: | 2013–2016 |
| Team1: | Elektra Šoštanj |
| Years2: | 2016–2020 |
| Team2: | Primorska |
| Years3: | 2020–2022 |
| Team3: | Krka |
| Years4: | 2022–present |
| Team4: | Cedevita Olimpija |
| Highlights: |
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Jan Kosi (born October 18, 1996) is a Slovenian professional basketball player for Cedevita Olimpija of the Slovenian League. He is a 2.04 m tall Power forward.
Kosi started playing professional basketball for Elektra Šoštanj.
In September 2016, Kosi signed with Sixt Primorska.[1]
On June 16, 2022, he has signed with Cedevita Olimpija of the Slovenian League.[2]