The second tier of the British rugby league system comprises 13 clubs – 12 from England and one from France.
Promoted from League One in 2024 were Oldham and Hunslet who replaced the 2024 relegated teams, Swinton Lions, Whitehaven and Dewsbury Rams.
In March 2024 the RFL completed the review and announced that the first steps will be taken to equalise the number of teams in the Championship and League One at 12 each by the start of the 2026 season.
After the four rounds have been completed, the top two teams will automatically qualify to play in the 2026 Championship.
The losers of this match and the teams finishing fifth to eighth will play in League One in 2026.