Hermione Baddeley (November 13, 1906 - August 19, 1986) was a celebrated British character actress of theatre, film and television.

Originally Hermione Youlanda Ruby Clinton-Baddeley, she was born in Broseley, Shropshire . She and her sister (the actress Angela Baddeley of Upstairs, Downstairs fame) moved in elevated social circles, Hermione's first husband being the Hon. David Pax Tennant, a descendant of William the Conqueror and elder brother of Stephen Tennant. Hermione was known for standout supporting performances in such films as Mary Poppins, The Belles of St. Trinian's, The Unsinkable Molly Brown, The Pickwick Papers, Tom Brown's Schooldays and A Christmas Carol.

Her television roles brought her increased visibility; besides many guest appearances she became known to American TV audiences for her roles in Little House on the Prairie and Maude. She was also a sought-after voice-over actress (The Aristocats, The Secret of NIMH). She continued to work until shortly before her death, in Los Angeles, California, of a stroke.