Playboi Carti Charged with Assault for Allegedly Punching Limo Driver

Playboi Carti got into some trouble while on tour -- he was charged with misdemeanor assault during his time in Utah earlier this month, law enforcement says.

Here's what we know -- cops say a limo driver named Carl Reynolds told them the "Rather Lie" rapper assaulted him while he was driving him and his entourage from the Waldorf Astoria in Park City to rehearsals on Oct. 2. Carti was in town for his Antagonist Tour at the time.

Carl claims things took a disastrous turn when Carti and his other half got into a heated argument -- apparently over sex -- in the back seat ... and he says Carti threatened to beat up both her and Carl after he intervened.

TMZ is told Carl says Carti wound up punching his GF in the chest, prompting Carl to pull over to a safer location on the highway in Heber City. However, Carl admitted he did not actually see Carti hitting his girlfriend, but saw her "hunched over holding near her chest" ... a police report obtained by KSL reads.

Carl also says he urged Carti's head of security to remove the Opium rapper from his vehicle and ride in the one with him.

That's when Carl claims Carti socked him in the kisser out of the blue as his girlfriend was exiting the vehicle, leaving him with a bruised, swollen jaw and a whiplash effect ... before Carti's head of security apparently broke up the fight.

Carl -- who was working for ALC A Limousine Connection when the altercation allegedly went down -- claims another driver for ALC witnessed the attack.

TMZ is told Wasatch County police were called to the scene and took photos of Carl's injuries. The department confirmed to TMZ they were investigating.

We're told Carl's preparing to lawyer up but says he mainly wants to ensure that Carti doesn't hurt anyone else -- including his GF.

The "Popular" artist was cited for assaulting the limo driver in this case ... not his partner.