Lil Baby landed behind bars Monday in Las Vegas ... 'cause he got busted for possessing an illegal weapon.
The rapper (real name: Dominique Jones) was arrested Monday night for carrying a concealed weapon without a permit – a felony – and hauled off to the Clark County Detention Center, where he was being held on $5,000 bail.
It appears the Baby was in Vegas celebrating NBA star James Harden's birthday.