Katherine "Scottie" MacGregor (born January 12, 1925 in Glendale, California) is an American television actress. In the 1940s she was hired by the Arthur Murray Dance Studios in New York City as a dance instructor. She is best known for her brilliantly-acted comic performance as Harriet Oleson from 1974 to 1983 on the NBC television series Little House on the Prairie.
Mrs. Oleson was at the same time both onerous and endearing to children and adults alike, as audiences watched her character practice self-aggrandizement, usually to her own detriment. MacGregor was able to infuse both pathos as well as depth into her deeply woven characterization of Mrs. Oleson, bringing the character far beyond the typical 'villain' role into something much more substantial and memorable. In 1979, thanks to the popularity of "Little House" and of her character in particular, MacGregor was invited to appear on Spanish Television's 625 Lineas program. After Little House on the Prairie, Katherine MacGregor withdrew from screen productions in favor of local theater. She also dedicated herself to her Hindu religion, and to teaching acting to children at the Wee Hollywood Vedanta Players.
Beginning in the 1950s, Katherine MacGregor worked in theatre on and off Broadway, and earned the part of 'a longshoreman's mother' in Elia Kazan's film, On the Waterfront, starring Marlon Brando. MacGregor also appeared in numerous episodes of Ironside, Mannix, Emergency! and East Side/West Side, as well as the 1981 "Heros vs Villains" episode of Family Feud hosted by Richard Dawson.