The 21-year-old was unveiled as the new face of the Dark & Lovely beauty brand at the Juliet Supper Club in New York.
Bria, whose sister Shayne Murphy was also at the Chelsea hot spot, celebrated with a Beau Joie champagne toast.
She said: 'I have been relaxing my hair with Dark & Lovely since I was 11.'
As the company’s new Global Brand Ambassador, she will star in both print and TV campaigns for Dark & Lovely’s Healthy Gloss 5.
Also at the Juliet Supper Club, were actress Adrienne Bailon, male model Tyson Beckford, celebrity stylist June Ambrose, socialite Bai Ling, and designer Anthony Williams.
Murphy and Mitchell were married from 1993 to 2006.