| Competition: | OB I |
| Season: | 2008–09 |
| Winners: | Vasas (16th title) |
| Continentalcup1: | Euroleague |
| Continentalcup1 Qualifiers: | TEVA-VasasPlaket ZF-Eger DOMINO Honvéd |
| Continentalcup2: | LEN Cup |
| Continentalcup2 Qualifiers: | Aprilia FTC-Fisher Klíma Szeged Beton |
| League Topscorer: | Márton Szívós (83 goals) |
| Prevseason: | 2007–08 |
| Nextseason: | 2009–10 |
2008–09 Országos Bajnokság I (men's water polo) (known as the Vodafone férfi OB I osztályú Országos Bajnokság for sponsorship reasons) was the 103rd water polo championship in Hungary.
| Team | M | Gy | D | V | G+ | G− | P | |
|---|---|---|---|---|---|---|---|---|
| 1. | TEVA-VasasPlaket | 22 | 21 | 1 | 0 | 282 | 141 | 64 |
| 2. | DOMINO Honvéd | 22 | 17 | 2 | 3 | 253 | 174 | 53 |
| 3. | ZF-Eger | 22 | 17 | 0 | 5 | 271 | 164 | 51 |
| 4. | Aprilia FTC-Fisher Klíma | 22 | 16 | 1 | 5 | 223 | 150 | 49 |
| 5. | Szeged Beton VE | 22 | 13 | 3 | 6 | 220 | 165 | 42 |
| 6. | Pécsi Vízmű PVSK-Fűszért | 22 | 11 | 2 | 9 | 190 | 186 | 35 |
| 7. | UNIQA-UTE | 22 | 8 | 3 | 11 | 223 | 225 | 27 |
| 8. | BVSC-Atlantis Casino | 22 | 8 | 0 | 14 | 190 | 226 | 24 |
| 9. | OSC-Opus Via | 22 | 4 | 2 | 16 | 162 | 261 | 14 |
| 10. | Szolnoki Főiskola-KÖZGÉP | 22 | 3 | 4 | 15 | 165 | 228 | 13 |
| 11. | Bodrogi Bau-Szentesi VK | 22 | 2 | 2 | 18 | 148 | 286 | 8 |
| 12. | Androbau Fehérvár Póló SE | 22 | 1 | 2 | 19 | 141 | 262 | 5 |
| Championship Playoff | ||
| European competition Playoff | ||
| Relegation Playoff |
TEVA-VasasPlaket won the FINAL series 3–1.
| 1 Viktor Nagy, 2 Bálint Takács, 3 Márk Kállay, 4 Gergely Katonás, 5 Norbert Hosnyánszky, 6 Viktor Vörös, 7 Róbert Kovács Csatlós, 8 Márton Tóth, 9 Dénes Varga, 10 Dániel Varga, 11 Barnabás Steinmetz, 12 Gábor Kis, 13 Dávid Hőna, 14 György Jónás | |
| Head coach: László Földi |
| Team | M | W | D | L | G+ | G− | P | BP | |
|---|---|---|---|---|---|---|---|---|---|
| 5. | Szeged-Beton VE | 6 | 6 | 0 | 0 | 68 | 46 | 30 | 12 |
| 6. | Uniqa-Újpesti TE | 6 | 3 | 1 | 2 | 54 | 52 | 16 | 6 |
| 7. | Pécsi Vízmű-Pécsi VSK-Fűszért | 6 | 2 | 0 | 4 | 61 | 63 | 15 | 9 |
| 8. | BVSC-Atlantis Casino | 6 | 0 | 1 | 5 | 54 | 76 | 4 | 3 |
| LEN Cup qualification |
| Team | M | W | D | L | G+ | G− | P | BP | |
|---|---|---|---|---|---|---|---|---|---|
| 9. | OSC-Opus Via | 6 | 3 | 2 | 1 | 66 | 54 | 23 | 12 |
| 10. | Szolnoki Főiskola VSC-Közgép | 6 | 4 | 0 | 2 | 52 | 48 | 21 | 9 |
| 11. | Bodrogi Bau-Szentesi VK | 6 | 2 | 1 | 3 | 51 | 60 | 13 | 6 |
| 12. | Androbau-Fehérvár Póló SE | 6 | 1 | 1 | 4 | 54 | 61 | 7 | 3 |
| Relegation |
| width=10px bgcolor=#ccffcc | Qualified for the 2009–10 LEN Euroleague | ||
| width=10px bgcolor=#bbebff | Qualified for the 2009–10 LEN Cup | ||
| width=10px bgcolor=#ffcccc | Relegation to the 2009–10 OB I/B |