The film stars Julianne Moore and Steve Coogan as a former couple fighting over the right to keep their 6-year-old daughter Maisie (Onata Aprile).
When her father marries Joanna Vanderham's Margot, the mother convinces Lincoln (Alexander Skarsgård) to play the part of her new husband.
As the parents war with each other, Maisie finds herself drawing closer to her stepmother and stepfather.
Scott McGehee and David Siegel directed the modern adaptation of Henry James's 1897 novel.
Moore will star in the upcoming Carrie remake and the fantasy adventure movie The Seventh Son. Coogan will lend his voice to Despicable Me 2 and is currently filming Alan Partridge: The Movie.
What Maisie Knew will arrive in cinemas in the spring.