Rachel Bilson Celebrates 21st Birthday of 'The O.C.,' Says She'd Be Rivals With Her Character

Rachel Bilson celebrated the 21st birthday of her hit series The O.C. on Wednesday (July 31) in Los Angeles.

The 42-year-old actress, who played Summer Roberts on the popular show, marked the occasion at an event, which also signified the launch of The O.C. x 21Seeds “Serving Summer” campaign, a collaboration with the tequila brand.

For the occasion, she looked stylish in a bubblegum pink dress with cutouts and a floral accent. Rachel wore her hair down and paired the dress with a matching bag and platform heels.