Trivia

The film used the fake working title "A Spiritual Journey" in order to obtain interviews with religious leaders. They were unaware that Bill Maher was involved in the film until he arrived for the interviews.

During the sequence set inside the Dome of the Rock, Bill Maher and his guide are approached by two men who are upset and then proceeded to speak in Arabic and supposedly talk about how Maher is "not funny." In actuality, what they said was, "We don't normally hang out here..." and "The boss only gives us five minutes..."

Additional people interviewed on the "Deleted Scenes" section of the DVD release include: Howard Bloom, an anti-Muslim Jew and author of "The Lucifer Principles," M. Hasan, a store owner, Kaya Bousquet, a model, Jason Alper, a stylist; Zamzan Books and Burkah Store (discussing Muslim fashions), Benjamin Creme, a British author, artist and prophet (discussing Maitreya), David Icke, author, of "The Biggest Secret," and "Secrets of the Matrix" (arguing that the world is being run by "interdimensional" reptile-like creatures including the Bushes and the British royal family), Rael, and followers discussing their "atheist religion" that extraterrestrials called "Elohim" created all life on earth. . Michael Bray (anti-abortion activist from Wilmington, Ohio defending violent attacks on abortion providers even if uninvolved people are also hurt or killed) . Anne, Heidi, Carla, Doris Deborah, Michelle and Miranda (polygamist wives of a fundamentalist Mormon living in Salt Lake City, Utah)

All of the "s"s on the DVD's closed captioning are dollar signs ($).

The title "Religulous" is a portmanteau of "religious" and "ridiculous"