Eric Millegan (born August 25, 1974) is an American actor, primarily known for his work on the Fox series Bones in which he played Dr. Zack Addy. Millegan is openly gay, and was out before being cast as Addy in Bones. Millegan was born in Hackettstown, New Jersey, and raised in Springfield, Oregon. Millegan began his musical theatre career at age 7, in the 1981 Eugene Opera production of Menotti's Amahl and the Night Visitors. He continued with the company in several other productions, including Madame Butterfly, La Bohème, Carmen, and Hansel and Gretel. Millegan appeared on Broadway in the 2000 production of Jesus Christ Superstar. In January 2005, he starred as Harold opposite Estelle Parsons' Maude in the world premiere of Tom Jones and Joseph Thalken's Harold & Maude: The Musical at the Paper Mill Playhouse in Millburn, New Jersey. In 2006, he returned to Eugene, Oregon to play Frederic in Eugene Opera's production of The Pirates of Penzance. In August 2009, Millegan released a video on YouTube in which he comes out about his experiences living with rapid-cycling bipolar disorder.