Mary Sue Hubbard was the third wife of L. Ron Hubbard, from 1952 until his death in 1986. She was a leading figure in Scientology for much of her life. The Hubbards had four children: Diana, Quentin (1954–1976), Suzette, and Arthur.

Lafayette Ronald Hubbard was an American author and the founder of Scientology. A prolific writer of pulp science fiction and fantasy novels in his early career, in 1950 he authored Dianetics: The Modern Science of Mental Health and established organizations to promote and practice Dianetics techniques. Hubbard created Scientology in 1952 after losing the intellectual rights to his literature on Dianetics in bankruptcy. He would lead the Church of Scientology, variously described as a cult, a new religious movement, or a business, until his death in 1986.