Mary Jo Catlett (born September 2, 1938) is an American actress and comedian. She has been a main cast member on the animated series SpongeBob SquarePants since its debut, providing the voice of Mrs. Puff. She is also known for originating the role of Ernestina in the 1964 Broadway production of Hello, Dolly! and for playing Pearl Gallagher, the third housekeeper on Diff'rent Strokes.