Melissa Sue Anderson (born September 26, 1962) is an American actress. She played the role of Mary Ingalls on the NBC television series Little House on the Prairie, which aired from 1974 until 1983. She won an Emmy Award for her performance in Which Mother Is Mine? (1979). One of her more recent performances was as First Lady Megan Hollister in the 2006 television mini-series 10.5: Apocalypse.