The actress, who also starred in TV series Gunsmoke and The Bionic Woman, was suffering from cancer.
As Cha Cha, she stole the limelight dancing the hand jive with Danny (John Travolta) at the school dance competition.
She continued acting into the late eighties, but latterly moved into teaching near her home in California.
According to reports, she had only recently been diagnosed with cancer – and died from complications linked to the disease.
Her death comes only two months after Jeff Conaway, who played Kenickie in the hit 1978 musical, passed away.