The popstar chose a sheer cream cardigan for a viewing of the French fashion house's autumn haute couture collection.
She chose to vamp up the piece of clothing but wearing it open at the bust and skirt, revealing a lot of skin in the process.
Rihanna paired the sweater-dress with a layered Chanel pearl necklace, a mini handbag and two-tone heels.
The singer tweeted about attending the show, writing: "Went straight to the Chanel Couture show early this morning with NO SLEEP!!! It was so worth it!!!"
Also in attendance at the show was Kristen Stewart, who made an impact in a white double-breasted Chanel jacket and micro shorts. She finished off the look with black fingerless gloves, obviously taking a leaf out of Karl Lagerfeld's style book.
Take a look at other celebrity sightings at Paris Fashion Week below.
Gemma Arterton
Anna Dello Russo
Emma Roberts, Mena Suvari
Jennifer Lawrence
Uma Thurman
Olivia Palermo
Carine Roitfeld
Bee Shaffer, Anna Wintour