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.
Pld - Played; W - Won; L - Lost; G+ - Points for; G− - Points against; Diff - Difference; P - Points.
TEVA-VasasPlaket won the FINAL series 3–1.
Pld - Played; W - Won; L - Lost; G+ - Points for; G− - Points against; Diff - Difference; P - Points; BP - Bonus Points.
Pld - Played; W - Won; L - Lost; G+ - Points for; G− - Points against; Diff - Difference; P - Points; Bp - Bonus Points.