Selena Gomez is Marchesa Marvelous

Selena Gomez looks stunning in a magenta Notte by Marchesa silk gown as she arrives at the UNICEF Ball held at the Beverly Wilshire Hotel in Beverly Hills on Thursday evening (December 10).

The 17-year-old actress was appointed UNICEF’s Trick-Or-Treat ambassador for the second year in a row earlier this year and recently made a trip to Ghana with the organization.

Selena was also just named Teen Vogue‘s Best Dressed Celeb of 2009, toppling over Camilla Belle and Keke Palmer. Congrats, Sel!