Mary Jo Catlett is an American actress. She is a main cast member on the animated series SpongeBob SquarePants, 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. Catlett was born in Denver, Colorado, where she performed in a variety of plays and eventually directed a company of Pirates of Penzance.