2018–19 Országos Bajnokság I (men's water polo)

The 2018–19 Országos Bajnokság I (known as the e·on férfi OB I osztályú Országos Bajnokság for sponsorship reasons) was the 113th season of the Országos Bajnokság I, Hungary's premier Water polo league.

Team information
The following 16 clubs compete in the OB I during the 2018–19 season:

Schedule and results
In the table below the home teams are listed on the left and the away teams along the top.

Schedule and results
In the table below the home teams are listed on the left and the away teams along the top.

Championship round
The top four teams, from two groups advance from the regular season. Teams start the Championship round with their points from the Regular season.

Schedule and results
Key numbers for pairing determination (number marks position after 14 games )

In the table below the home teams are listed on the left and the away teams along the top.

Relegation round
The bottom four teams, from two groups advance from the regular season. Teams start the Relegation round with their points from the Regular season.

Schedule and results
In the table below the home teams are listed on the left and the away teams along the top.

1st – 4th Placement matches

 * Semi-finals


 * Game 1

FTC-Telekom Waterpolo won the series 9–0 with points ratio, and advanced to the Finals.

A-HÍD OSC Újbuda won the series 9–0 with points ratio, and advanced to the Finals.

Finals
Higher ranked team hosted Game 1 and Game 3 plus Game 5 if necessary. The lower ranked hosted Game 2 plus Game 4 if necessary.

FTC-Telekom Waterpolo won the Final series 3–0.

Third place
Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.

Szolnoki Dózsa won the Third place.

5th – 8th Placement matches
Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.
 * Fifth place game (European competition play-off)

Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.
 * Seventh place game

9th – 12th Placement matches
Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.
 * Ninth place game

Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.
 * Eleventh place game

13th – 16th Placement matches
Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.
 * Thirteenth place game

Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2.
 * Fifteenth place game (Relegation play-out)

Relegation play-out
Higher ranked team hosted Game 1 plus Game 3 if necessary. The lower ranked hosted Game 2. VasasPlaket won the 2–0 on series and therefore both clubs remain in their respective leagues.