Then in the '90s, she stepped away from the spotlight – for good.
On Wednesday night, PEOPLE caught up with the actress at the Love Boat reunion in Fort Lauderdale, where the cast gathered to christen a new Regal Princess cruise ship and celebrate 50 years of Princess Cruises. McNichol, who appeared as a guest star on the show, said she left show business to "see what else was out there."
"I was on the big stage between ages 8 and 30," McNichol, 52, tells PEOPLE. "I left show business for a variety of reasons, but a big one was my interest in learning what else there is in life."
So what did she discover? A newfound love of yoga, for one, along with traveling, an increased awareness of spirituality and a quiet home life.
"This phase of my life is so good," she says. "My home life is happy and serene. I love singing. I also enjoy traveling and seeing the world. One of my favorite stops is Hawaii. I like everything about it and may eventually move there part-time." The actress says she also spends a lot of time doing charity work for United Way.
At the Love Boat reunion, McNichol was thrilled to be able to catch up with some of her old Hollywood pals.
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McNichol adds that her favorite memory from guest-starring on the popular maritime series was becoming close friends with actor Scott Baio.
"We met during shooting, and for the next three years we hung out off set, too," McNichol says. "We became real friends, good buddies. We did things together like ride around in his red Cadillac. We had so much fun. I wished he could have come to this celebration, but he was busy."
And how about a return to acting? "Never say never," she says.
But, she added, an escape on the fancy cruise ship sounded more appealing to her: "I love this ship. I'd like to stow away, travel the globe and never come back!"