Olivia Newton-John, who on Monday aged 73, reportedly worried she was 'too old' to play the part of high school student Sandy Olsson in 1983 movie musical Grease.
But the actress, who was 29 when she was cast as the fresh-faced teenager, is far from the only star to have played a much younger character on screen.
Her Grease co-star Stockard Channing was 34 when she played fellow Pink Lady and Sandy's frenemy Rizzo.
Barbara Streisand was in her 40s when she was cast as the 19-year-old titular character in 1983 film Yentl, while British actress Shirley Henderson was in her late 30s when she first appeared as 14-year-old ghost schoolgirl Moaning Myrtle in the Harry Potter series.
Some turns are more successful than others. Viewers were amazed when they learned Irish actress Nicola Coughlan, who plays a teenager in both Bridgerton and Derry Girls, is in her 30s.
But The Vampire Diaries star Ian Somerhalder, who was 31 when the series started, never quite passed for a 17-year-old.
Here, FEMAIL reveals the other actors who've played much younger characters with varying degrees of success...
Stockard Channing in Grease (1978)
Age: 34, playing 17-year-old Pink Lady Rizzo
Shirley Henderson in Harry Potter
Age: The actress was 36 when she first played ghost schoolgirl Moaning Myrtle, 14
Emma Thompson in Sense and Sensibility (1995)
Age: Dame Emma, then 35, was cast as 19-year-old Elinor Dashwood
Nicola Coughlan in Bridgerton and Derry Girls
Age: Nicola was 33 when she first played Penelope Featherington in Bridgerton. She also appears as a teenage schoolgirl in Derry Girls
Ian Somerhalder in The Vampire Diaries
Age: The actor played vampire Damon Salvatore, 17, from the ages of 31-38
Stacey Dash in Clueless (1995)
Age: 28 when she was cast as Dionne Davenport, 17
Wood Harris in Remember the Titans (2000)
Age: Harris was 31, playing 18-year-old high schooler Julius Campbell
Henry Winkler in Happy Days
Age: Winkler was 29 when he first played teenager The Fonz
Audrey Hepburn in Breakfast at Tiffany's (1961)
Age: Hepburn was 32 when she played 19-year-old Holly Golightly
Cory Monteith in Glee
Age: The late actor was 27 when he was cast as Finn, 16
Barbara Streisand in Yentl (1983)
Age: Barbara was 44, playing titular character Yentl Mendel, 19