The 2020–21 Országos Bajnokság I (also known as the E.ON Férfi OB I Bajnokság for sponsorship reasons, OB I in short), is going to be the 115th season of top-tier water polo in Hungary.
The following 16 clubs compete in the OB I during the 2020–21 season: In the table below the home teams are listed on the left and the away teams along the top.
Szolnoki Dózsa won the series 7–1 with points ratio, and advanced to the Finals.