| 2002–03 LEN Champions League | |
| League: | LEN Champions League |
| Sport: | Water Polo |
| Duration: | 16 October 2002 to 17 May 2003 |
| No Of Teams: | 8 (preliminary round) 29 (total) |
| Playoffs: | Final Four |
| Playoffs Link: | 2002–03 LEN Champions League#Final Four (Genoa) |
| Finals Champ: |  Pro Recco (3rd title) |
| Seasonslist: | LEN Champions League |
| Seasonslistnames: | Champions League |
| Prevseason Link: | 2001–02 LEN Champions League |
| Prevseason Year: | 2001–02 |
| Nextseason Link: | 2003–04 LEN Euroleague |
| Nextseason Year: | 2003–04 |
The 2002–03 LEN Champions League was the 40th edition of LEN's premier competition for men's water polo clubs. It ran from 16 October 2002 to 17 May 2003, and it was contested by 29 teams. The Final Four (semifinals, final, and third place game) took place on May 16 and May 17 in Genoa.
| width=25 | ! | width=220 | Team |
|---|---|---|---|
| Pro Recco | |||
 Honvéd | |||
| HAVK Mladost | |||
| Spandau 04 |
| Jesús Rollán, Alberto Angelini, Luca Giustolisi, Danilo Ikodinović, Simone Mina, Vladimir Vujasinović, Daniele Bettini, Tibor Benedek, Paolo Petronelli, Alessandro Calcaterra, Massimiliano Ferretti, Alessandro Caliogna, Alberto Ghibellini | |
| Head coach | |
| Marco Baldineti |