Her dazzling smile made her America's sweetheart when she won figure skating gold in the 1976 Winter Olympics in Innsbruck, Austria.
At nineteen years old, Hamill was thrust into the spotlight and mobbed for autographs. She was a star, but she didn't feel like one.
"When you have that goal and you have that dream and it actually happens, you think that it would be a switch," she told CBS News correspondent Thalia Assuras. "And that all of a sudden you'd feel, you know, like an Olympic champion. And I didn't feel any different."
At 51, Hamill now recognizes that she, like some 20 million Americans, suffers from depression. It was a family secret that tarnished her Olympic gold. She reveals the truth behind her victory in her new book, "A Skating Life: My Story."
"My whole family," she said, "my father's side, there was a great deal of depression, and my mother's side as well."
Hamill had a strained relationship with her mother, who she said had a lot of negative feelings.
"And I think passed that on to, actually, my brother and my sister as well as me," she said.
The youngest of three children, it was Hamill who had the drive and determination to become a world class figure skater. And it was her mother who woke at 4 every morning to drive her to the rink. A mother, she now realizes, whose own depression often left the little girl sad and confused.
"Very complicated, yes," she said of her relationship with her mother. "I'm still searching to try and figure it out."
During Hamill's proudest moment, on the Olympic podium in 1976, her mother was back at the hotel. It is a memory that still hurts.
"I guess it was the one time where I really hoped that she would say, 'I'm proud of you.' Or, you know, 'We did well together,'" Hamill said. "It was kind of sad and disappointing."
After the Olympics, Hamill began spiraling into different worlds. She did a famous commercial for Clairol shampoo, championing the "short and sassy" haircut. She turned pro and commanded high prices as a performer in the Ice Capades.
And there was romance with Dean Paul Martin, son of the legendary Dean Martin, whom she married in 1982. She began living the Hollywood lifestyle of a movie star.
"It really was a magical time," she said. "It really was."
But there was also a great deal of stress. Hamill was working herself to the point of exhaustion. Martin struggled with his own demons as the son of a star and the husband of America's sweetheart. The two divorced. A short time later, Martin was killed when his plane crashed into the San Gordino Mountains shortly after take off on a routine training mission.
Hamill still keeps his photo in her bedroom.
"I think there was still that sort of sense of hope that maybe one day we would get back together," she said.
But it was her second divorce, from Ken Forsythe, involving a bitter custody battle and bankruptcy after the couple's Ice Capades business failed, that drove Hamill to the brink of despair.
"I would describe it as I'd be sitting there having a conversation. Everything would be fine and then I would just be in tears," Hamill said. "Uncontrollable tears, and you know, wanted to sort of - suicidal times. I was in my car and I just kinda wanted to drive into a wall, a cement wall, and be done with it. It was my daughter, just the thought of 'I would never do something so selfish as to leave her, you know, without a mom.'"
Her daughter Alex, now a freshman in college, has inherited the family illness, a struggle her mother wishes she didn't have to endure.
"It's knowing the pain," she said. "You know, how just awful it is."
Today, despite an active performing schedule, lots of friends and a busy life in Baltimore, Hamill still has bouts of depression.
"It's all I can do to get off the couch or, you know, can't even unload a dishwasher. I mean, it really is debilitating," she said.
Medication and therapy help, says Hamill. But perhaps what keeps her on track and what has kept her from complete darkness is what she's known and loved her whole life.
"That sort of magical cool air and the wind at my face and music," she said. "It just sort of always lifts me out of my funk."