|Born||Muriel Joan Warry
|Known for||Chairman of the executive committee of the Girl Guides Association|
Dame Joan Marsham (1888–1972) was a British philanthropist and chairman of the executive committee of the Girl Guides Association from 1938 to 1948. She was Chairman of the National Women's Auxiliary of the Young Men's Christian Association (founded in Britain in 1918) from 1931 until 1972.
Born as Muriel Joan Warry, the daughter of William Warry of Shapwick, Somerset, England, she married the Hon. Sydney Edward Marsham, son of Charles Marsham, 4th Earl of Romney and Lady Frances Augusta Constance Muir Rawdon-Hastings, on 2 February 1911.
- Husband: Hon. Sydney Edward Marsham (b. 29 December 1879 - d. 6 January 1952)
- Child: Lt.-Col. Peter William Marsham (b. 8 June 1913 - d. 1970)