The Rugby Football League Championship, (known as the Betfred Championship for sponsorship reasons) is the second highest division of rugby league in Britain .

Introduced in 2003 as National League One, it replaced the existing Second Division. It was rebranded as the Championship in 2009.

The league consists of 14 teams, with the winner decided by a playoff. The current champions are Wakefield Trinity, winners of the 2024 season after beating Toulouse Olympique in the Championship Grand Final.

In 2026, the Championship will merge with League One, thus seeing an expansion to 21 teams. This was catalysed by Super League's expansion from 12 to 14 teams also in 2026 which would see two clubs promoted from the Championship without replacement and would have left the Championship with only 11 clubs.

Second division rugby league competitions have been played at various times since 1902, and have been in place annually since 1973. When Super League began in 1996, the second division continued to operate a system of promotion and relegation with the new competition. In 1999, the second-tier competition below the Super League was renamed the Northern Ford Premiership (NFP) when Northern Ford Dealers acquired the naming rights.

In 2003, the NFP was re-organised into National Leagues One and Two. Teams that finished in the top ten league positions of the 2002 Northern Ford Premiership joined National League One and the bottom eight joined National League Two. They were joined by London Skolars from the Rugby League Conference, who entered National League Two, and York City Knights, who replaced the defunct York Wasps (who had folded mid-season in 2002) and also joined National League Two in 2003, creating two ten-team leagues which operated a system of promotion and relegation between themselves while also maintaining the promotion and relegation between National League One and Super League.

At the same time, National League Three was created with teams from the Rugby League Conference and from the British Amateur Rugby League Association amateur leagues. It was intended that there would be promotion and relegation between National League Two and National League Three when League Three became more established, however this never eventuated.

In 2009 Super League was expanded to 14 teams, with two additional teams being promoted from National League One. In turn, two additional teams were promoted from National League Two to National League One at the end of the 2008 season, reducing the number of teams in National League Two to 10. National Leagues One and Two were then rebranded as the Championship and Championship 1 respectively, with the change being implemented in time for the 2009 season. Championship 1 was later rebranded to League 1. During this period, a system of licensing was put in place which meant there was no automatic system of promotion and relegation between the Championship and Super League, although promotion and relegation continued between the Championship and League 1. Widnes Vikings were promoted to Super League from the Championship via the licensing system in 2011.