Barton is originally from Valley Stream, Long Island, New York. As a youngster, he was terrified of Cruella De Vil from One Hundred and One Dalmatians (1961). He is a graduate of Valley Stream North High School, where he played soccer and wrestled. He attended nearby Nassau Community College. Although accepted into St. John's University School of Medicine, he changed his mind about attending. Just before signing up for classes, he decided to pursue a career in modeling and acting.
Even though Barton had no formal acting training, in 1979 he starred as Bill Miller in the short-lived NBC TV series, Shirley, starring Shirley Jones, Rosanna Arquette, and Tracey Gold. The show ran for 13 episodes. NBC still had him under contract at the end of 1980, and it connected him with prominent acting coach Vincent Chase, and when the series ended, he was cast as the lead in another NBC series, The Powers of Matthew Star. He won the role over many actors, among them Tom Cruise.
In the 1980s, teen magazines were looking for the next big cover, and Barton was featured on many of them, including Tiger Beat and 16, typically in a sexy pose, shirtless. He has also appeared on many TV shows such as The Fall Guy and The Love Boat and daytime soap operas like The Young and the Restless.
Barton saw his popularity dwindling by the end of 1983, and he "wanted to give up acting". However, he became involved in the burgeoning teen horror/thriller film genre, beginning with Hell Night (1981) and followed by Friday the 13th: The Final Chapter (1984).
I had just been talked into doing this movie called Hell Night, with Linda Blair. I didn't even want to do it — they had to get me drunk to convince me. So it was a miserable time, and it was a great time. I wouldn't exchange the experience of making Hell Night, even though I was petrified all the way through it. So when The Final Chapter was offered to me, I was like, 'I don't really want to do Friday the 13th.' Eventually, I only did it because of Amy Steel — she talked me into it. And I thought it was really cool because it was The Final Chapter. In my mind, I thought, 'Oh, I'll be in the last one. That's kind of cool. These things are famous.' Little did I know.
After outgrowing his ability to appear as a teenager, Barton acquired mostly television roles as an adult. He starred on Burke's Law with Gene Barry and the soap opera Sunset Beach. His last appearance to date was in the 2005 film Repetition.
Peter Barton has never married.
In February 2013, a man in Illinois named Ray Fulk died at age 71. Fulk, who had no family of his own, was a fan of Peter Barton and Barton's friend, Lucan star Kevin Brophy. Despite never having met either actor, Fulk bequeathed half of his estate to each of the actors.