TMZ caught Def Jam founder Russell Simmons out last night in New York City, rolling up with a beautiful young blonde in his car.  It's unclear what the relationship is, but Russell did open the door for her.

It was confirmed back in March that Simmons was splitting with his wife Kimora Lee, and since then the hip-hop mogul had been rumored to be dating rap video model Denise Vasi.  The unknown woman in our video looks about the same age as Vasi, who is in her early twenties, and equally beautiful.