RFL League One
| Current season, competition or edition: 2025 RFL League One | |
| Sport | Rugby league | 
|---|---|
| Founded | 2003 | 
| No. of teams | 11 | 
| Country | England Wales | 
| Most recent champion(s) | Oldham (2nd title) | 
| Most titles | Dewsbury Rams (3 titles) | 
| Level on pyramid | 3 | 
| Promotion to | Championship | 
| Domestic cup(s) | Challenge Cup 1895 Cup | 
| Official website | League One | 
The Rugby Football League's League One (known as the Betfred League One) is the third-highest division of rugby league in Britain. It is also the lowest level of professional rugby league in Britain.
Introduced in 2003 as National League 2 it was the first time British rugby league had a third tier since the old Third and Second Divisions merged in 1998. The league was rebranded as Championship 1 in 2009, then League 1 in 2015, and League One in 2022.
The current winners are Oldham who won the league in 2024.