The 2024-25 Japan Rugby League One – Division 1 season is the fourteenth top flight league season played from December 2024 through to June 2025,[1] in the newly rebranded Japan Rugby League One.

The competition consisted of twelve teams, including one promoted team from Division 2, the Urayasu D-Rocks.

The format will consist of a round-robin fixture, before entering into a knockout style play-off for the final four teams.

Teams in each conference played the teams in their respective conference twice (one at home, one away), and six matches against all the teams in the other conference, three being at home and three away.

Each team played a total of sixteen seasonal fixtures, plus additional play-off matches, including relegation play-offs.