| Club: | Osasuna |
| Season: | 2002–03 |
| Chrtitle: | President |
| Manager: |  Javier Aguirre |
| Stadium: | El Sadar |
| League: | La Liga |
| League Result: | 11th |
| Cup1: | Copa del Rey |
| Cup1 Result: | Semifinals |
| League Topscorer: | John Aloisi (8) |
| Pattern La1: | _osasuna01021 |
| Pattern B1: | _osasuna0203h |
| Prevseason: | 2001–02 |
| Nextseason: | 2003–04 |
The 2002–03 CA Osasuna season is the 82nd season in the club's history.in the La Liga.
Osasuna finished the season in 11th position in the La Liga table. In other competitions, Osasuna reached the semifinals of the Copa del Rey.
John Aloisi was the top scorer for Osasuna with 8 goals in all competitions.
Osasuna's kit was manufactured by Spanish sports retailer Astore and sponsored by Caja Navarra.
See main article: 2002–03 La Liga.
See main article: 2002–03 Copa del Rey.