Országos Bajnokság I (men's water polo)

Országos Bajnokság I (OB I) is the premier professional men's water polo league in Hungary. It is administered by the Hungarian Water Polo Federation (Magyar Vízilabda Szövetség). The league is considered one of the strongest water polo leagues in the world, featuring many internationally renowned players and clubs.

The competition typically involves multiple stages, including a regular season followed by playoffs or a championship series. The number of teams participating can vary from year to year. The winner of the OB I is crowned the Hungarian national champion.

Numerous clubs have achieved success in the Országos Bajnokság I, with some consistently dominating the league for extended periods. The league's history spans many decades, and it plays a significant role in the development and promotion of water polo in Hungary. Many players from the OB I go on to represent the Hungarian national team in international competitions, contributing to Hungary's strong tradition in the sport.

The league operates under rules and regulations set by the Hungarian Water Polo Federation, adhering to international standards for water polo. The season typically runs from autumn to spring. Matches are usually well-attended, with passionate fans supporting their respective teams.