Katharine McPhee & Kathy Bates Step Out for Good Cause at American Cancer Society's Birthday Ballat 2015!

Katharine McPhee strikes a pose on the red carpet while attending the 2015 American Cancer Society’s Birthday Ballat held at The Beverly Hilton Hotel on Saturday (June 6) in Beverly Hills, Calif.

The 31-year-old entertainer was joined by her You May Not Kiss the Bride co-star, hostess Kathy Bathes and Gabourey Sidibe, who came out to show her support.

PHOTOS: Check out the latest pics of Katharine McPhee

Katharine hit the stage for a special performance at the event to help raise funds for The American Cancer Society, which is a nationwide voluntary health organization dedicated to eliminating cancer.

FYI: Katharine is wearing a Ronny Kobo top, Paule Ka skirt, Stuart Weitzman shoes, and Jennifer Meyer necklace.

30+ pictures inside of Katharine McPhee and others at the event…