The 2011–12 Long Beach State 49ers men's basketball team represented California State University, Long Beach during the 2011–12 NCAA Division I men's basketball season. The 49ers, led by fifth year head coach Dan Monson, played their home games at Walter Pyramid and are members of the Big West Conference. They finished the season 25–9, 15–1 in Big West play to be crowned regular season champions. They were also champions of the Big West Basketball tournament to earn the conference's automatic bid into the 2012 NCAA tournament where they lost in the second round to New Mexico. The 49ers were the only Los Angeles-area college basketball team to make the tournament that year.