Gwendoline See-Hian Yeo was born in Singapore, Gwendoline is the niece of George Yeo, Singapore's Minister for Foreign Affairs. She moved to California as a teenager, graduating (with honors) from St. Ignatius College Preparatory in 1994. She received her BA from UCLA before the age of 20, graduating summa cum laude, Phi Beta Kappa as well as receiving a diploma in Classical Piano from the esteemed San Francisco Conservatory of Music. Her love of music led her to specialize in playing the traditional Chinese instrument, guzheng, which culminated in a one woman radio show on NPR-KCRW. It also included the debut of her first two zither/vocal tracks "Kiss My Grits" and "Lovers." Gwendoline was crowned Miss Chinatown USA in 1998-1999 which led her to hosting and commercials. From there, her television and film careers blossomed.

Prior to her acting career, she was active in a variety of beauty pageants, winning the Miss Asian America Pageant in 1995 and the Miss Chinatown USA Pageant.

During her career she played Dr. Kelly Lee on General Hospital, until March 2006. Her first airdate was January 3, 2006. Originally involved in the Jax and Courtney baby story, she seems to be the only OBGYN practicing at General Hospital.

Her past appearances include television series 24, JAG, NYPD Blue and The O.C.. Gwendoline guest starred in an episode of Hannah Montana and Chuck. Gwendoline guest starred as Xiao-Mei in a few episodes of "Desperate Housewives". She is the voice actress of Paine in Final Fantasy X-2 and Kingdom Hearts II. She also voices Lady Deathstrike in X-Men: Next Dimension, Mercy Graves in The Batman, Li-en in Zatch Bell!, and Lieutenant Keiko Tanaka in an episode of What's New, Scooby Doo?.

She has appeared in the films Daughters of Joy, Night Skies, and The Perfect Girl. In the film Broken Trail, she played "Sun Foy" and was called "number three" by Robert Duvall's character. In 2007, she played Dr. Samantha Yep in The Jane Austen Book Club.

She is sometimes confused with another voice actress, Gwendolyn Lau.