Harriet E. McGibbon was born in Chicago to Dr. Walter Peter McGibbon and Gertrude L. McGibbon. It is not known why she amended her surname by adding an "a", but she was credited a few times as McGibbon. She was "finished" at Knox School, Cooperstown, New York, where she prepared for Vassar. Without staying to receive a diploma, she left to fulfill her desire for the footlights and studied with Franklin H. Sargent at the American Academy of Dramatic Arts in New York City. Later, MacGibbon joined the stock company of Edward Clarke Lilley at Akron, Ohio. She then went to San Francisco and played leading roles for Henry Duffy. In Louisville, Kentucky, she acted with Wilton Lackaye, Edmund Breese, William Faversham, Tom Wise and Nance O'Neil. There were regular productions, including Ned McCobb's Daughter, The Front Page, The Big Fight, and a "transcontinental tour" starring MacGibbon in The Big Fight, which began in Boston, took in New Haven and Hartford, and ended at Caine's storehouse. During all of her travels while performing, MacGibbon managed to remain in Boston long enough to study the harp with Alfred Holy, first harpist with the Boston Symphony Orchestra. She later said that when she gave up the instrument, Mr. Holy, "with unconscious humor", remarked, "What a pity, Miss MacGibbon, you look so lovely with a harp." She had a long and distinguished career on the Broadway stage, beginning in 1925 at the age of nineteen when she acted in the play Beggar on Horseback at the Shubert Theatre. In the late 1930s, she did You Can't Take It With You, the Pulitzer Prize winning comedy, at the Biltmore Theatre in Downtown Los Angeles. From 1934 to 1937, MacGibbon portrayed Lucy Kent on the NBC radio soap operaHome Sweet Home. Her film debut was a non-speaking bit as a snooty woman walking a dog across a golf course in W.C. Fields' first talkie, The Golf Specialist, shot in Fort Lee, New Jersey. She made numerous guest appearances on television starting in 1950, including Bewitched, Ray Milland's sitcom Meet Mr. McNutley. Another sitcom in which MacGibbon appeared was My Three Sons, performing as Margaret Cunningham opposite William Frawley, in the 1961 episode "Bub Goes to School". She was cast in only five theatrical motion pictures, including Four Horsemen of the Apocalypse, which was directed by Vincente Minnelli and starred Glenn Ford, Ingrid Thulin, Charles Boyer, and Lee J. Cobb. Unlike her stage roles, MacGibbon's movie and television roles usually consisted of snooty society ladies, including her well-known role as Margaret Drysdale on The Beverly Hillbillies.
MacGibbon was married twice: to William R. Kane and later to Charles Corwin White Jr., which ended when White died on December 25, 1967. With her first husband she had one child, a son. Ten years after the death of her son, MacGibbon died at age 81 due to heart and lung failure. She was cremated, and her ashes interred in niche 61046 in the Columbarium of Remembrance at Forest Lawn Memorial Park, Los Angeles, California.
