The project is scheduled to start shooting Sept. 7 in Vancouver, with Kathleen Marshall making her film directing debut. Marshall won a directing Tony for her Broadway revival of "Wonderful Town."
"Once Upon a Mattress" is a twist on the children's fairy tale "The Princess and the Pea." Ullman will star as Princess Winnifred -- the role that Burnett first played on Broadway. Burnett will play the villainous Queen Aggravain.
"It all fell together when I said, 'We've got to get Tracey,' and everyone agreed," Burnett told Variety. "And who's funnier than Tracey Ullman? I can't wait to get into the sandbox with her and play."