| Name | Lifetime | Left | Notes |
| Larry Anderson | 1952– | 2009 | Actor, star of Orientation: A Scientology Information Film, left the church in 2009 and requested his money back. |
| Gerry Armstrong | 1946– | 1981 | Former Sea Org member for ten years and involved in a series of Scientology related lawsuits, collectively Church of Scientology of California v. Armstrong. |
| Jon Atack | 1955– | 1983 | Whistleblower and noted critic of the church. |
| Allen Barton | 1968– | 2012 | Playwright and acting teacher who would later become an outspoken critic of the church. |
| Jason Beghe | 1960– | 2007 | Actor, rose to Operating Thetan level V (OT V), left Scientology and subsequently spoke out publicly against the church in 2008. He joined the church through Milton Katselas' acting class, connecting with Bodhi Elfman and Mary Thompson. |
| Cedric Bixler-Zavala | 1974– | 2017 | Musician. |
| Nazanin Boniadi | 1980– | | Actress, her mother was a Scientologist. |
| Kate Bornstein | 1948– | 1981 | Transgender author, playwright, performance artist and gender theorist. Was previously a spokesperson for Scientology. |
| Mitch Brisker | 1949– | 2020 | Producer. |
| John Brodie | 1935– | | American football player; credited Dianetics with his recovery from a sports injury; left after some of his friends "were expelled and harassed during a power struggle with church management" |
| Stacy Brooks | 1952– | 1989 | Former managing editor of Freedom magazine and a Scientologist for over twenty years. She has since become president of the Lisa McPherson Trust and an expert witness in many high-profile Scientology lawsuits. |
| William S. Burroughs | 1914–1997 | 1960s | Author and poet. Joined and left the church during the 1960s. In talking about the experience, he claimed that the techniques and philosophy of Scientology helped him and that he felt that further study into Scientology would produce great results. He was skeptical of the church itself, and felt that it fostered an environment that did not accept critical discussion. His subsequent critical writings about the church and his review of Inside Scientology by Robert Kaufman led to a battle of letters between Burroughs and Scientology supporters in the pages of Rolling Stone magazine. He wrote the book Ali's Smile: Naked Scientology. |
| Diana Canova | 1953– | 1993 | Actress; critical of Scientology's "straightforward" desire for money. |
| Tory Christman | 1947– | 2000 | Whistleblower and noted critic of the church. |
| Robert DeGrimston | 1935– | | With wife, Marry Anne DeGrimston, founder of The Process Church of The Final Judgment. |
| Richard de Mille | 1922–2009 | 1954 | Author and journalist; at one point a personal assistant to L. Ron Hubbard. |
| John Duignan | 1963– | | Whistleblower and noted critic of the church. |
| Dennis Erlich | 19xx– | 1982 | Former high-ranking official in the church and later critic of Scientology who joined the alt.religion.scientology discussion group on Usenet in late July 1994. |
| Michael Fairman | 1934– | 2011 | Actor |
| Neil Gaiman | 1960– | | Novelist, graphic novelist, and screenwriter. Son of David Gaiman, raised Scientologist in East Grinstead. Has left the church, although prefers not to speak publicly about it. |
| Philip Gale | 1978–1998 | | Massachusetts Institute of Technology student and primary developer of EarthLink's innovative ISP software; died by suicide in 1998. |
| Paul Haggis | 1953– | 2009 | Film director, Academy Award winner; Left in response to the San Diego branch's public support of California Proposition 8 and other factors. He progressed up to OT VII in the 1980s where he remained until he left the church. |
| Beck Hansen | 1970– | 2019 | Musician who promoted Scientology as a member for many years. Stated in a 2019 interview that he is not a Scientologist and that he doesn't "have any connection or affiliation with it". |
| Marc Headley | 1974– | 2005 | Whistleblower and critic of the church. |
| Katie Holmes | 1978– | 2012 | Actress and formerly married to Scientologist Tom Cruise. |
| Jim Humble | 1933– | 1981 | Self-published author and founder of the Genesis II Church |
| Robert Hunter | 1941–2019 | 1999 | Lyricist for the Grateful Dead. |
| Mark Janicello | 1962 | 2003 | Actor, Singer and Dramatist. Author of Naked in the Spotlight: My Life with Sex, Singing, and Scientology in German and in English |
| Nicole Kidman | 1967– | 1992 | Actress; Tom Cruise's ex-wife |
| Jason Lee | 1970– | 2016 | Actor |
| Arnie Lerma | 1950–2018 | 1977 | Son of a high-ranking member. Critic of Scientology who posted the Fishman Affidavit, including the Xenu story, to the Internet via the Usenet newsgroup alt.religion.scientology. |
| Johnny Lewis | 1983–2012 | | Actor |
| Juliette Lewis | 1973– | 2021 | Actress |
| Charles Manson | 1934–2017 | | Identified as a Scientologist during his time in prison. He ordered Manson Family member Bruce Davis to journey to the United Kingdom and work for the Scientology organization in London. Manson completed 150 hours of auditing while researching his own religious practices, which borrowed heavily from Scientology. |
| Jenna Miscavige Hill | 1984– | 2005 | Niece of David Miscavige, author and whistleblower. |
| Ron Miscavige | 1936–2021 | 2012 | Father of David Miscavige, author and whistleblower. |
| Vince Offer | 1964– | 2002 | Film director of The Underground Comedy Movie and pitchman for ShamWow. |
| Bijou Phillips | 1980– | 2024 | Model and actress |
| Laura Prepon | 1980– | 2016 | Actress |
| Lisa Marie Presley | 1968–2023 | 2014 | Singer and songwriter who was the daughter of Elvis Presley. |
| Priscilla Presley | 1945– | 2017 | Businesswoman and actress |
| Mark Rathbun | 1957– | 2004 | Whistleblower, and critic of the Church. In December 2018, Jezebel reported that Rathbun had posted videos on his website that praised Scientology and criticized ex-Scientologist Leah Remini. Jezebel also suggested that Rathbun had actually re-joined Scientology. |
| Joe Reaiche | 1958–2024 | 2005 | Former rugby league footballer who was the father of Alanna Masterson and Jordan Masterson. He accused the church of framing him for financial misconduct and was estranged from his children at the time of his death. |
| Leah Remini | 1970– | 2013 | Actress and critic of the church. She wrote an autobiography in 2015 entitled Troublemaker: Surviving Hollywood and Scientology, and produces and presents the A&E documentary series Leah Remini: Scientology and the Aftermath. |
| Mike Rinder | 1955–2025 | 2007 | Whistleblower and critic of the church. |
| Mimi Rogers | 1956– | | Actress |
| Amy Scobee | 19xx– | 2005 | Whistleblower and critic of the church. |
| Chris Shelton | 1969– | 2012 | Author and YouTuber; he was a member of the church for 27 years and has been outspoken about his experiences since leaving. |
| Aaron Saxton | 1974– | 2006 | Former Sea Org member who had influential positions in Sydney as well as the United States. He received attention when Australian Senator Nick Xenophon quoted statements by Saxton about Scientology into the parliamentary record of the Australian Senate. |
