The 2011–12 First League of the Republika Srpska is the seventeenth season of the First League of the Republika Srpska, the second tier football league of Bosnia and Herzegovina, since its original establishment and the tenth as a second-tier league. It began on 13 August 2011 and ended on 26 May 2012; a winter break where no matches will be played was in effect between 5 November 2011 and 10 March 2012. Kozara were the last champions, having won their first championship title in the 2010–11 season and earning a promotion to Premier League of Bosnia and Herzegovina. This year Radnik won the championship, the third time they won the First League of the Republika Srpska.
14 clubs participated in this session, eleven returning from the previous session, one relegated from Premier League of Bosnia and Herzegovina and two promoted from two regional Second League of the Republika Srpska.
Unlike the last season, this season the Football Federation of the Republika Srpska decided to add relegation play-offs. Along the two last placed clubs in the league table which get relegated, the twelfth ranked team has to play relegation play-offs against the winner of the Second League of the Republika Srpska promotion play-offs which is contested between the two runners-up of the two Second Leagues of the Republika Srpska.[3]
Sloboda (NG) as 12th-placed team faced the winner of the promotion play-offs contested between the two runners-up of the two Second Leagues of the Republika Srpska, runner-up of the Second League of the RS - West side Jedinstvo in a two-legged play-off. Sloboda (NG) won 5–0 on aggregate and thus were not relegated from the First League of the Republika Srpska. Jedinstvo also remained in their respective league.