Tory Lanez was arrested on a gun charge after an argument outside a house party in the Hollywood Hills on Sunday.
TMZ reports the rapper was busted after police responded to a 911 call around 4:30 a.m. Sunday.
Witnesses told police that people were arguing in an SUV before someone fired shots in the air and the SUV drove off at a high rate of speed.
A short while later police located the SUV and found Lanez and Megan Thee Stallion inside along with another woman.
Megan had a cut on her foot believed to be from broken glass on the floor of the vehicle.
Cops searched the vehicle and recovered a firearm. Lanez was taken into custody and booked into the county jail for carrying a concealed weapon without a license.
Earlier on Saturday night, Megan and Lanez attended a pool party at Kylie Jenner's upscale Holmby Hills home.