The couple, who met on the set of the film A Beautiful Mind, will play the Darwins in a film following the life of the father behind the theory of evolution.
Jon Amiel will direct the project, which was inspired by the biography by Randal Keynes, Annie’s Box.
According to The Hollywood Reporter, the film will show how Charles Darwin was tortured by the conflicts surrounding his love for his wife, who was a very religious woman, and his strong belief that God doesn’t exist.
In addition to Connelly and Bettany, the film also stars Jeremy Northam, Toby Jones and Benedict Cumberbatch. Filming is set to begin next September in England.