Mary Jo Catlett (born September 2, 1938) 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. Throughout the 1960s and 1970s, she performed in Off-Broadway and Broadway musicals, often taking light-hearted, humorous roles. Since the late 1960s, Catlett has appeared in television shows such as M*A*S*H, The Dukes of Hazzard, and General Hospital. Catlett received Los Angeles Drama Critics Circle Awards in 1978 and 1980, a nomination for Best Featured Actress in a Musical at the Ovation Awards in 1995, and a Daytime Emmy Award nomination in 1990.In 1998, Catlett joined the main cast of the then-upcoming cartoon SpongeBob SquarePants as the voice of Mrs. Puff, the title character's teacher, who has become her longest-running and most well-known role. Series creator Stephen Hillenburg had seen Catlett perform on stage and sought her out for the part himself. She quickly accepted and has since voiced Mrs. Puff in every season of the cartoon, in addition to all of the theatrical SpongeBob films and video games. In 2001, she received an Annie Award nomination for her voice-over work as Mrs. Puff.