Jon Koppenhaver, who legally changed his name to War Machine, was also sentenced to three years on probation.
The 28-year-old won't be allowed to possess or consume alcohol or enter bars and nightclubs during this time.
The former mixed martial arts championship fighter pleaded guilty last month to two counts of assault with force likely to cause great bodily injury.
The charges related to two separate bar fights - one where he assaulted a female bartender by sweeping bottles off the bar at her and the other when he punched a bouncer, KFMB-TV reported.
At the time, he was also on probation for a 2008 misdemeanor assault conviction.