Rachel McAdams in 'Mean Girls' - Rachel McAdams was already 26 years old when she played Regina George in 'Mean Girls' (2004), a character that still haunts her to this day.
Gabrielle Union in 'Bring It On' - Gabrielle Union is best known for her role in 'Bring It On,' where she played a high school cheerleader at the age of 27.
Ashleigh Murray in 'Riverdale' - Ashleigh Murray played a teenager in the teen drama series 'Riverdale.' She is 35 years old.
Felicity Jones in 'Breathe In' - When Felicity Jones played teenage Sophie in 'Breathe In' (2013), she was 29.
Troian Bellisario in 'Pretty Little Liars' - Bellisario was 25 when the show first aired, and 29 when it ended. She played teenager Spencer Hastings.
Robert Pattinson in 'Twilight' - Pattinson played the forever-teenage Edward Cullen in the 'Twilight' saga, a role that has earned the then 26-year-old actor many awards.
Emilia Clarke in 'Game of Thrones' - The British actress began playing her initially 16-year-old character on 'Game of Thrones' when she herself was 25.
Jason Earles in 'Hannah Montana' - The actor was 29 when he started playing his role as 16-year-old Jackson Stewart in 'Hannah Montana.'
Andrew Garfield in 'The Amazing Spider-Man' - The actor played 17-year-old Peter Parker in the film 'The Amazing Spider-Man.’ However, he was 31 at the time.
Taylor Kitsch in 'Friday Night Lights' - Actor Taylor Kitsch took on the role of sophomore Tim Riggins in the show 'Friday Night Lights.' The actor's actual age was 27.