He will join Charlize Theron and Chloe Moretz in the adaptation of Gillian Flynn's novel, reports Deadline.
Theron stars as Libby Day, a woman who is forced to confront the truth about the murder of her family when she was a young child.
Hoult will play Lyle, the treasurer of the Kill Club - the organisation that pressures Libby to reconsider whether the brother she helped convict was truly guilty.
The actor was most recently seen in Warm Bodies and Jack the Giant Slayer. He will next appear in Mad Max: Fury Road - also with Theron - as well as X-Men: Days of Future Past.
Gilles Paquet-Brenner will write and direct Dark Places.