The actors wore the outfits for a Meet ‘n’ Grease fan singalong event, which involved a screening of the film and a Q&A with the two stars. Newton-John wore a yellow pleated skirt, white shirt and a matching yellow cardigan as part of her 'Good Sandy' alter-ego, while Travolta chose Danny Zuko's signature leather biker jacket and black trousers.
The actors shared a picture of themselves in costume on their respective Instagram feeds. "First time in costume since we made the movie ! So excited!" wrote Newton-John.
In November, Newton-John sold her iconic leather trousers that she wore in the Grease finale for Dhs595,026 (£121,510). The costume was bought by Spanx founder Sara Blakely, who has been a fan of the movie since she was young. The trousers were sold among 500 items belonging to Newton-John as part of an auction raising money for the actress' cancer treatment centre in Sydney.
Earlier this year, Newton-John was diagnosed with breast cancer for the third time.