Melissa Sue Anderson is an American actress who has a net worth of $4 million dollars. She is best known for her role as Mary Ingalls on the NBC television series, Little House on the Prairie. Anderson began her acting career at the age of nine, when she appeared in a regional production of The Wizard of Oz. She went on to appear in a number of television commercials and guest starring roles on various television series, before landing the role of Mary Ingalls. Little House on the Prairie ran for nine seasons and Anderson appeared in all of them. She has since appeared in a number of made-for-TV movies and guest starring roles on television.