The 37-year-old heavyweight was taken into custody at about 1:15 a.m. by officers who conducted a traffic stop at Cahuenga and Sunset boulevards, according to the Los Angeles Police Department.
Wilder was booked on suspicion of carrying a concealed firearm in a vehicle, and bail was set at $35,000, according to the LAPD and the Los Angeles County Sheriff's Department. He was released at about 6:35 a.m., the sheriff's department reported.
According to TMZ.com , Wilder was pulled over after LAPD officers "claimed his Rolls-Royce's windows were illegally tinted and his license plate was obstructed." Police said they smelled marijuana, prompting a search of the vehicle.
"Our sources say they then found weed and a 9mm in the vehicle, and put Wilder into custody. We're told the 6-foot-7 fighter was cooperative and nice throughout the whole ordeal," the website reported.
Wilder -- who has a 43-2-1 record with 42 knockouts on his resume -- is a former WBC heavyweight champion best known for his three fights against current WBC champion Tyson Fury. The first fight was a draw, with Fury winning the next two. Wilder is rumored to be the next opponent for former champion Anthony Joshua.