John Travolta and his wife, Kelly Preston, have long been devotees of Scientology. Travolta has been a Scientologist for more than 30 years, and Preston caught on to the faith through her acting coach, Milton Katselas, who also brought actress Anne Archer into the fold.

Tom Cruise is perhaps the most famous Scientologist on the planet and is said to have reached one of the most elite levels within the religion. He introduced ex-wife Nicole Kidman to the religion as he did his ex-wife, Katie Holmes.

Kirstie Alley is best known for her role in the 1980s comedy "Cheers." She has spoken out against people who make fun of Scientology, calling them bigots. Alley said that society would never tolerate other religions being mocked in the same way.

Elvis Presley's daughter, singer Lisa Marie Presley, said she was drawn to Scientology because founder L. Ron Hubbard understood artists. She said the religion is like an encyclopedia for life. Scientologist John Travolta once said Presley was like a surrogate daughter.

Actress Jenna Elfman and her husband, actor Bodhi Elfman, are famous for jumping to their religion's defense when they spotted someone wearing an offensive shirt. Their target was Indie film director John Roecker who wore a T-shirt featuring an image of Tom Cruise with the words: "Scientology is Gay!" on the front and a picture of John Travolta from "Saturday Night Fever" on the back with the words "Very Gay!"

"King of Queens" star Leah Remini had long been unapologetic about her steadfast practice of Scientology. She credited the religion's therapies with helping her get pregnant. Remini also said that the religion helped her get through troubled times in her life. But in July 2013, she reported said she had parted ways with Scientology. Remini thanked fans and colleagues for their support after word spread about her reported departure.

Actress Elisabeth Moss, who has starred on "The West Wing" and "Mad Men," practices Scientology.

The late singer Isaac Hayes, shown here with his wife, Adjowa, and their son, Nana Kwadjo, quit his role as the Chef on "South Park" after the show made fun of Scientology. He later says that the Scientology jokes offended him, but he quit over money.

Actor Giovanni Ribisi credits Scientology with keeping him off drugs. He once said: "Without Scientology, I would be in an alley somewhere, looking for dope."

Actress and singer Juliette Lewis was born into Scientology. When she became heavily involved in drugs, she turned to a Scientologist-run clinic. She says the religion keeps her grounded.

When married to Mimi Rogers, Tom Cruise converted to Scientology. Roger's father is one of the church's founders.

Actress Erika Christensen has been a Scientologist since she was 8 and said Tom Cruise is one of her mentors. She said Scientology helps her with acting because of its focus on communication.

Jazz musician Chick Corea is known for promoting Scientology through his music. Corea used to exchange letters with Scientology founder L. Ron Hubbard. Corea said that Scientology promotes "universal values."

Actress Catherine Bell is a member of the Citizens Commission for Human Rights, an anti-psychiatry organization that is part of the church of Scientology. She has spoken out against the use of drugs like anti-depressants, as has Kelly Preston and Tom Cruise.

"That '70s Show" star Danny Masterson was raised as a Scientologist. He helped promote the Scientology Museum called "Psychiatry: An Industry of Death" when it opened in 2005. His brother, actor Chris Masterson, is also a Scientologist.

Greta Van Susteren, a legal commentator for Fox News, is also a devout Scientologist. She has said she identifies with the religion's ethics.

Beck has been involved with Scientology for most of his life. The singer publicly made reference to his faith for the first time in an interview published in The New York Times Magazine.

Priscilla Presley, actress and former wife of singer Elvis Presley, is a devoted member of the Church of Scientology. She has also spoken publicly for the group's anti-psychiatry group.

Actor Jason Lee is a member of the Church of Scientology and his ex-wife, Carmen Llewellyn, who converted to the religion for Lee, spoke out against Scientology in 2010. She claimed Scientology "ruined" her life.

Peaches Geldof, the late British socialite and daughter of rocker Bob Geldof, was also a Scientologist.

Filmmaker Paul Haggis, one of the Church of Scientology's most notable members, resigned from the church in 2009 out of anger over the church's implicit support of California's Proposition 8, the ban on same-sex marriage. Haggis was featured prominently in the revealing documentary about Scientology, "Going Clear."