She began taking acting classes and appeared very early in the London theatres and British television productions.
[4] Baeza has acted in a number of films and television programmes, including the 1998 film Far from the Madding Crowd playing the leading role of Bathsheba Everdene,[5] and the 2008 BBC production The Passion as Mary Magdalene.
[4] Baeza directed a short feature film Watchmen in 2001, which she wrote with actor Cillian Murphy, who also starred.
[2][8] In 2018, she began directing a CG/live-action film, The Toymaker's Secret, written by her husband Alex Garland.
[10] Baeza is married to screenwriter, novelist, and film director Alex Garland; they have a son, Milo, and a daughter, Eva.