Rihanna & Drake -- Rendezvous in Paris

Paris ain't called the City of Love for nothing -- Rihanna and Drake are both in town ... and they can't stay away from each other.

Drake is in Paris for a concert -- he performed last night -- but he and Rihanna have been hanging out since the weekend ... grabbing a fancy dinner at Paris's famous L'Avenue restaurant Sunday.

Rihanna re-connected with Drake at his concert the next day ... slipping in the rear entrance.

After last night's concert, the on-again off-again couple hit up a nightclub ... and from there, we're told they both crashed at the Hyatt hotel, where Drizzy has a room.

Guess that means they're on again.