"Simpsons" executive producer Al Jean called said in a statement Saturday that her "irreplaceable character," the fourth-grade teacher who contended with Bart Simpson's constant antics, would be retired from the show. Wallace was 70.
"I was tremendously saddened to learn this morning of the passing of the brilliant and gracious Marcia Wallace. She was beloved by all at The Simpsons," Jean said. It's "a terrible loss for all who had the pleasure of knowing her."
The statement did not provide a date for her death, or a cause.
The longtime TV actress' credits ranged from playing a receptionist on "The Bob Newhart Show" to appearances on Candice Bergen's "Murphy Brown."
On "The Simpsons," Wallace provided the voice for world-weary Edna Krabappel (cru-BOP'-pul), who smoked cigarettes, made sarcastic comments and finally found love in the arms of Simpson's neighbor Ned Flanders after fans voted online at the end of season 22 to keep the unlikely couple together.
Wallace's trademark "Ha!" punctuated Krabappel's frequent wisecracks, and her character was also known for the catchphrase, "Do what I mean, not what I say."
Harry Shearer, the voice of Ned Flanders on the show, said Wallace "brought this huge, positive energy" to her work on "The Simpsons."
"She was just a warm and wonderful person," Shearer told The Associated Press.