The 2011–12 A-1 League (Croatian: A-1 liga 2011./12.) was the 21st season of the A-1 League, the highest professional basketball league in Croatia.
The first half of the season consisted of 11 teams and 110-game regular season (20 games for each of the 11 teams) began on Friday, October 8, 2011 and ended on Wednesday, March 14, 2012. The second half of the season consisted of 3 teams from ABA League and the best 5 teams from first half of the season. Playoffs started on May 15, 2012 and ended on June 5.
Relegation league 5th-placed team Dubrovnik faces the 2nd-placed Promotion league side Crikvenica in a two-legged play-off. The winner on aggregate score after both matches will earn a spot in the 2012–13 A-1 League.