Richard Treat Williams (born December 1, 1951) is an American actor, writer and aviator who has appeared on film, stage and television in over 120 credits. He first became well known for his starring role in the 1979 musical film Hair, and later also starred in the films Prince of the City, Once Upon a Time in America, The Late Shift and 127 Hours. From 2002 to 2006, he was the lead of the television series Everwood and was nominated for two Screen Actors Guild Awards. He has additionally been nominated for three Golden Globe Awards, two Satellite Awards and an Independent Spirit Award.

Early life and education
Williams was born December 1, 1951 in Rowayton, Connecticut, the son of Marian (née Andrew), an antiques dealer, and Richard Norman Williams, a corporate executive. His maternal great-great-great-grandfather was Senator William Henry Barnum of Connecticut, a third cousin of the showman P. T. Barnum. Williams is a distant relative of Robert Treat Paine, who was a signatory to the Declaration of Independence.

Williams played football in high school. He graduated from the Kent School in Connecticut and Franklin and Marshall College in Pennsylvania.