The two will be writing the upcoming comedy, which doesn't currently have a name or a release date. The film, from TriStar Productions, is described as a story of "best friends who find themselves in over their heads and out of their depths, which were, perhaps not too deep to begin with."
"We're very excited to be writing," Wiig and Mumolo said in a statement. "We will be going into a cave for months to finish. An actual cave. We found one that's nice and big. We're putting a couch in there."
"I've been wanting to direct for some time now. This seems like the perfect first project," Wiig added.
The pair were nominated for an Academy Award in the original screenplay category for 2011's Bridesmaids. The film, which cost $32.5 million, took in $288.4 million.
2014: The Year in Music [PHOTOS]