John Travolta, who starred as 'Grease' bad boy heartthrob Danny Zuko, crashed the Hollywood Bowl's sing-along event Friday. He surprised the audience and "Grease" co-stars alike.

Screen icon John Travolta made a surprise appearance at a "Grease" sing-a-long at the Hollywood Bowl this weekend.

An emotional Travolta paid tribute to his “Grease” co-star Olivia Newton-John at the Oscars in 2023. Newton-John, who played Australian teen Sandy Olsson in the movie, died of cancer in 2022. Thank you for reading. Please consider supporting NJ.com with a subscription.