RiRi was dripping in diamonds as she chowed down at Giorgio Baldi in Santa Monica.

It's her go-to when she's in L.A. Great restaurant and less of a scene than a lot of WeHo eateries.

We can't tell if she was with BF A$AP Rocky, but they've been in town lately at a recording studio, which brings us to ... THE SUPER BOWL!!!

TMZ broke the story ... Rihanna will be headlining the upcoming Super Bowl halftime show. We're told there's a long list of singers/rappers who might join her, but as of a few days ago no decisions were made. It's also possible, we're told, she could do it alone.