David Frankel will direct the film, which is being co-financed by Village Roadshow. Smith is starring alongside Helen Mirren, Edward Norton, Naomie Harris and Michael Pena.
Producers are Anthony Bregman, Bard Dorros, Allan Loeb, Michael Sugar and PalmStar CEO Kevin Frakes. Steven Pearl is exec producing.
Smith will portray a successful New York advertising executive who experiences a personal tragedy and retreats from life entirely, prompting his colleagues to devise a drastic plan to help him recover.
The movie will hit theaters on Dec. 16, 2016, putting it in prime position for an awards season run. Production will start this month in New York.
Knightley was most recently seen in “Everest.” She is repped by CAA, United Agents and MGMT Entertainment.