Mitchell was born in Mississauga, Ontario. She is an actress known to television audiences as Emily Fields on Freeform's Pretty Little Liars. In 2011, she received a Young Hollywood Award for her work on the hit show. She'd go on to star in Lifetime's You along with Penn Badgley.
She began her career as a model, participating in a notable campaign for American Eagle Outfitters.
In 2010, she appeared in a Disney XD series called Aaron Stone.
She was born to Precious and Mark Mitchell and raised alongside a younger brother named Sean. Her father is of Scottish and Irish descent and her mother, who is Filipina, is from the province of Pampanga. She has been in a relationship with Matte Babel. She and Babel welcomed a daughter named Atlas in 2019. She was previously romantically tied to Carlos PenaVega.
She appeared in Logan Paul's music video "Help Me Help You" alongside the band Why Don't We.