The pair have been confirmed for Paul Haggis's film from Belgian company Corsan, reports Deadline.
Wilde will appear as a party reporter and Neeson as her lover in the film spotlighting three interconnected stories set in New York, Rome and Paris.
In France, a frustrated writer continues an affair with a woman who is also in a sexual relationship with her father, while in the US a woman fights against attempted murder charges against her son in a custody case.
In Italy, an American businessman falls for a woman when helping to rescue her kidnapped daughter.
Wilde and Neeson were previously rumoured for the roles.
Neeson was last seen in Battleship.
Wilde recently reprised her role as Thirteen in the penultimate episode of House.