The native Australian singer who played Danny's star-crossed good-girl love was already a Grammy-award-winning singer with hits like "If You Love Me, Let Me Know" and "I Honestly Love You." But she had very little acting experience.
Fortunately, for Newton-John, Marie Osmond turned down the role of Sandy because she didn't like how the character becomes a "bad girl" in the end. After "Grease," Newton-John's career soared. Her next film "Xanadu" was a critical failure but did well at the box office and the film's soundtrack went double platinum. Newton-John followed up with "Physical," her most successful album to date.
Following a battle with breast cancer in 1992, Newton-John became a health advocate. She also divorced first husband, actor Matt Lattanzi, with whom she has a daughter Chloe, and began seeing camerman Patrick McDermott. They dated off and on for nine years until McDermott mysteriously disappeared during a boating trip. Years later, he was discovered living off the coast of Mexico.
In June 2008, Newton-John, now 61, secretly wed John Easterling, founder and president of natural remedy company. Recently, she earned a new generation of fans with a guest appearance on "Glee."
A stage veteran, Channing had a few bit roles in films before accepting the part of Rizzo, Sandy's polar opposite, at the ripe age of 33.
After her success in "Grease," Channing was rewarded with her own sitcoms. Both were short-lived, and she returned to the stage, taking one of those roles in "Six Degrees of Separation" to the big screen several years later. "Six Degrees" revived her film career in the 90s and she appeared in "Smoke," "The First Wives Club," and "Moll Flanders."
In recent years, the 66-year-old actress is best known as First Lady Abbey Bartlet in the hit series "The West Wing," for which she received an Emmy Award.
Conaway, now 59, began acting on Broadway at age 2, but it was his role as Danny's sidekick Kenickie in "Grease" that earned him fame.
He went on to star as out-of-work actor Bobby Wheeler in Taxi. After a number of television and film appearances, he landed another series playing Sgt. Zack Allan on "Babylon 5."
But his substance abuse problems and his appearances on the "Celebrity Rehab" series are what he's probably best known for now. On the VH1 reality show, he admitted his addiction to cocaine, alcohol and painkillers and talked about his sexual abuse as a child and his co-dependent relationship with his addict girlfriend Vikki. During his second season on the show, Conaway left rehab before graduation and was seen taking painkillers after he arrived home.
With her unmistakable childlike voice, Conn was memorable in her role of high school-turned-beauty school dropout Frenchy in "Grease."
Her career never achieved the same heights, though. She went on to star in several television series, including "Benson" and the children's show "Shining Time Station." These days, Conn, now 58, makes an occasional guest appearance. But mostly she serves as celebrity spokeswoman for Autism Speaks, since her son Danny was diagnosed with autism.
Lorenzo Lamas/Tom Chisolm