George Clooney, Josh Brolin, Tilda Swinton, Ralph Fiennes and Channing Tatum had already been attached to the Hollywood studios period comedy and now two more big names have been added to the fold.
Johansson previously worked with the Coen Brothers on their 2001 film The Man Who Wasn't There, while the project will mark another movie reunion for Hill and his 21 Jump Street co-star Tatum.
Celebrating the news on Twitter.com, Hill writes, "Hail, Caesar! So damn excited to get to work with the Coen Brothers!"
Filming is expected to begin this autumn (14), although a release date has yet to be set.