The 2011-12 NBL season was the 30th season for the Adelaide 36ers in the NBL. After missing out on the playoffs in 2010-11 for the 4th time in the past 5 seasons and finishing the season in 8th position with a worst ever 9-19 record the 36ers, who have won the NBL Championship four times (1986, 1998, 1998–99 and 2001-02) will be looking to get back to a position of power in the league.
The season is the second year of a 3-year contract for head coach Marty Clarke.
* Williamson was released by the Adelaide 36ers on 30 September 2011 due to a knee injury. He was replaced by the signing of Diamon Simpson on 10 October.
** Everard Bartlett signed as an injury replacement for Nathan Crosswell.
Along with season ending injuries to the clubs captain and vice-captain (Adam Ballinger and Nathan Crosswell) in Round 10, the 36ers performed well at times in 2011-12 but the young team's inability to close out games or win close games saw them ultimately record a club worst ever 8-20 record. For only the second time in its history dating back to when they started as the Adelaide City Eagles in 1982, the club finished the season in last place.
Bright spots for the team were the emergence of centre and the NBL's Most Improved Player for 2012 Daniel Johnson who finally got court time to show his potential and finished the regular season in 3rd place in league average scores (16.5ppg), 5th in rebounding (7.7rpg) and 5th in blocked shots (1.0pg) as well as exciting import power forwardDiamon Simpson who led the NBL in shooting percentage (59.2%), was 2nd in blocked shots (1.5pg) was 3rd in rebounding (8.6 rpg). Other bright spots in an otherwise dismal season included rookie import guard Chris Warren (14.2ppg) in his first professional role outside of college, the continued athleticism and defense of youngster Mitch Creek and the outside shooting of veteran Darren Ng.