"After seeing Meryl Streep's mesmerizing portrayal as Margaret Thatcher in 'The Iron Lady,' it has me even more excited and proud to co-star with her," Roberts said in a statement.
"I'm delighted and feel very privileged to have the opportunity to direct Meryl and Julia in this magnificent piece written by Tracy Letts," said Wells. "Meryl's extraordinary body of work made her the only conceivable choice to play Violet. Coupled with Julia's effortless mastery of every role she undertakes and her fearlessness as an actress, I'm confident this first-ever collaboration with Meryl and Julia will produce an exciting and moving film."
The producers describe the play as "the dark, hilarious and deeply touching story of the strong-willed women of the Weston family, whose lives have diverged until a family crisis brings them back to the Midwest house they grew up in, and to the dysfunctional woman who raised them."
Streep will play pill-popping matriarch Violet Weston, while Roberts will play her daughter Barbara.
Letts' play made its Broadway debut in December 2007 after premiering at Chicago's Steppenwolf Theatre earlier that year. It continued with a successful international run.