Mary Sue Hubbard, née Whipp; June 17, 1931 – November 25, 2002) was the third wife of L. Ron Hubbard, from 1952 to his death in 1986, and was a leading figure in Scientology for much of her life. She had four children by Hubbard – Diana (born 1952), Quentin (born 1954), Suzette (born 1955), and Arthur (born 1958).

She became involved in Hubbard's Dianetics in 1952, while still a student at the University of Texas at Austin, becoming a Dianetics auditor. She soon became involved in a relationship with Hubbard and married him in March 1952. She accompanied her husband to Phoenix, Arizona, where they established the Hubbard Association of Scientologists – the forerunner of the Church of Scientology, which was itself founded in 1953. She was credited with helping to coin the word "Scientology". She played a leading role in the management of the Church of Scientology, rising to become the head of the Church's Guardian's Office (GO). In August 1978, she was indicted by the United States Government on charges of conspiracy relating to illegal covert operations mounted by the Guardian's Office against government agencies. She was convicted in December 1979 and was sentenced to five years' imprisonment and the payment of a $10,000 fine. She was forced to resign her post in July 1981 and served a year in prison from January 1983, after exhausting her appeals against her conviction. In the late 1990s, she fell ill with breast cancer and died in 2002.

A Mary Sue (sometimes just Sue), in literary criticism and particularly in fanfiction, is a fictional character with overly idealized and hackneyed mannerisms, lacking noteworthy flaws, and primarily functioning as a wish-fulfilment fantasy for the author or reader. It is generally accepted as a character whose positive aspects overwhelm their other traits until they become one-dimensional. While the label "Mary Sue" itself originates from a parody of this type of character, most characters labelled "Mary Sues" by readers are not intended by authors as such. Male Mary Sues are often dubbed "Gary Stu", "Larry Stu", "Marty Stu", or similar names.

While the term is generally limited to fan-created characters, and its most common usage today occurs within the fan fiction community or in reference to fan fiction, original characters in role-playing games or literary canon are also sometimes criticized as being "Mary Sues" or "canon Sues" if they dominate the spotlight or are too unrealistic or unlikely in other ways. One example of this criticism is Wesley Crusher from Star Trek: The Next Generation.

For the Bicktertonite figure see Reorganized Church of Jesus Christ (Bickertonite)

Allen Wright (1825-1885) was Principal chief of the Choctaw from Fall 1866 to 1870. He also became a Christian minister after conversion. He has been credited with the name "Oklahoma" for the land that would become the state.

David Miscavige (born April 30, 1960) is the leader of the Church of Scientology and affiliated organizations. His title is Chairman of the Board of Religious Technology Center (RTC), a corporation that controls the trademarked names and symbols of Dianetics and Scientology. Miscavige was an assistant to Hubbard (a "Commodore's messenger") while a teenager. He rose to a leadership position within the organization by the early 1980s and was named Chairman of the Board of RTC. Miscavige's mandate is to protect the works of L. Ron Hubbard from distortion or misuse, and to serve as ecclesiastical head of Scientology.

Since assuming his leadership position, Miscavige has been faced with press accounts alleging illegal and unethical practices, both personally and through his organizational management. These include reports of forced separation of family members, coercive fundraising practices, harassment of journalists and church critics, and public humiliation of church staff members, including physical assaults by Miscavige. Miscavige and church spokespeople have consistently denied these charges, often raising counter-charges that attack the credibility of the journalists and sources responsible for the critical accounts.