A Los Angeles native, Holly is the daughter of cinematographer Hugh Gagnier, and Eleanor Gagnier a stenographer for the United Nations
She has been seen on many television series, including Baywatch, Pacific Blue, Middle Ages, Days of Our Lives and One Life to Live. She has done over 75 guest appearances, and over 50 national commercials.
Holly has also been in several motion pictures, and has worked opposite Adrien Brody, George Clooney, Scatt Caan and Alec Baldwin. She is ofte most recognized from the cult classic "Girls Just Wanna have Fun" opposite Helen Hunt and Sarah Jessica Parker.
Having travelled and lived in several parts of the world, Holly currently resides in Los Angeles with her nine year old daughter, Grace.