2009–10 Országos Bajnokság I (men's water polo)

2009–10 Országos Bajnokság I (men's water polo) (known as the Vodafone férfi OB I osztályú Országos Bajnokság for sponsorship reasons) was the 104th water polo championship in Hungary.

First stage
Pld - Played; W - Won; L - Lost; G+ - Points for; G− - Points against; Diff - Difference; P - Points.

European competition Playoff
Pld - Played; W - Won; L - Lost; G+ - Points for; G− - Points against; Diff - Difference; P - Points; BP - Bonus Points.

Relegation Playoff
Pld - Played; W - Won; L - Lost; G+ - Points for; G− - Points against; Diff - Difference; P - Points; Bp - Bonus Points.