Ella Summer Reed Purnell (born 17 September 1996) is an English actress who began her career as a child actress in West End theatre. Purnell used to attend weekly classes at Sylvia Young Theatre School studying acting, singing, and dance.

Purnell's film roles include Never Let Me Go (2010), Miss Peregrine's Home for Peculiar Children (2016), Churchill (2017), and Army of the Dead (2021), among others. Her television credits include Sweetbitter (2018), Belgravia (2020), Yellowjackets (2021), Arcane (2021), Star Trek: Prodigy (2021), and Fallout (2024).