The project, which has the working title Wichita, centres on a spy (Cruise) romancing a woman (Diaz) who has had bad luck with men. Lost star Grace will play the sister of Diaz's character.
James Mangold will direct the movie, his first since 2007's 3:10 To Yuma.
Grace recently appeared as Liam Neeson's kidnapped daughter in action film Taken. She also has Malice In Wonderland and The Experiment due for release in the next year.