| Competition: | OB I |
| Season: | 2002–03 |
| Winners: | Honvéd |
| Continentalcup1: | Euroleague |
| Continentalcup1 Qualifiers: | Honvéd Vasas BVSC |
| Prevseason: | 2001–02 |
| Nextseason: | 2003–04 |
2002–03 Országos Bajnokság I (men's water polo) was the 97th water polo championship in Hungary.
| Team | M | W | D | L | G+ | G− | P | |
|---|---|---|---|---|---|---|---|---|
| 1. | Domino-Bp. Honvéd | 22 | 18 | 3 | 1 | 260 | 110 | 39 |
| 2. | Vasas SC-Plaket-Euroleasing | 22 | 18 | 3 | 1 | 256 | 101 | 39 |
| 3. | BVSC-Brendon | 22 | 16 | 4 | 2 | 227 | 131 | 36 |
| 4. | Ferencvárosi TC-VMAX | 22 | 14 | 3 | 5 | 196 | 111 | 31 |
| 5. | Újpesti TE-Taxi2000 | 22 | 13 | 3 | 6 | 194 | 165 | 29 |
| 6. | Szeged-Beton VE | 22 | 14 | 0 | 8 | 185 | 144 | 28 |
| 7. | OSC-British Knights | 22 | 7 | 1 | 14 | 147 | 218 | 15 |
| 8. | ZF Hungária-Egri VK | 22 | 6 | 1 | 15 | 124 | 207 | 13 |
| 9. | Kontavill-Szentesi VK | 22 | 5 | 2 | 15 | 134 | 196 | 12 |
| 10. | Szolnoki VSC | 22 | 5 | 2 | 15 | 134 | 196 | 12 |
| 11. | Ceglédi VSE-Geosaurus | 22 | 2 | 2 | 18 | 101 | 214 | 6 |
| 12. | Kecskeméti VSC | 22 | 1 | 2 | 19 | 112 | 260 | 4 |
| Championship Playoff | ||
| Relegation |
| width=10px bgcolor=#ccffcc | Qualified for the 2003–04 LEN Euroleague | ||
| width=10px bgcolor=#bbebff | Qualified for the 2003–04 LEN Cup | ||
| width=10px bgcolor=#ffcccc | Relegation to the 2003–04 OB I/B |
| Attila Bárány, Miklós Bereczki, Péter Biros, Rajmund Fodor, Ottó Frikk István Gergely, Gergely Kiss, Olivér Kovács, Zoltán Kovács Tamás Molnár, Sándor Sugár, Márton Szívós Imre Tóth, Attila Vári | |
| Head coach | |
| István Kovács |