Cult Colony

If and when humanity ever goes out into space to establish colonies, unless we develop some sort of super-fast warp drive surprisingly early, the first few extrasolar colonies will be rather isolated for quite a while. They will also be rather expensive to set up. What sort of people would volunteer for such an endeavor? Who would willingly cut themselves off from all other human contact, leave all their friends, neighbors, and relatives behind, and strand themselves years away from any support, rescue, or even conversation quite literally light-years from home? And who could afford to build a Generation Ship, Sleeper Ship, or other large but low-tech means of journeying to another world with enough people and equipment to found a self-supporting colony on a brand new world?

A band of religious fanatics, that's who.

The sort of people who, in Real Life, build isolated compounds out in the middle of the desert. The sort who set out in leaky boats with names like "Mayflower" and cross vast oceans to build quaint little English villages in the middle of the wilderness on a barely-explored continent.

Even once colonization really gets going, there will still be groups of like-minded religious individuals who pool together their worldly wealth and found themselves a colony of their own, where they will be free from persecution (or perhaps just free to persecute the heck out of any of their number who aren't theologically pure enough).

This trope is for both colonies explicitly founded by monolithic religious organizations, whether mainstream or cult-like, and for colonies which, some time after their founding, become religiously monolithic due to a sort of revival fervor or the rise of a local charismatic religious leader who converts the vast majority of the population.

Frequently overlaps with Space Amish, when the rejection of technology is religiously based. Naturally qualifies as a Planet of Hats. In sci-fi, Mormons are a probably the favorite pick for this- although they are usually off-screen.

Anime and Manga

 * The much derided Moon-Moon colony, a Wacky Wayside Tribe in Mobile Suit Gundam ZZ.

Film

 * In Starship Troopers, "Mormon Extremists" build themselves Port Joe Smith, a fortified human outpost on planet a considered by the Arachnids to be part of their sphere of influence. It didn't end well.
 * In Pitch Black, Richard B. Riddick encounters Imam, a character determined to find the colony New Mecca, where multiple religious groups are alleged to co-exist without religious conflict.

Literature

 * Pick any Sci Fi-based Orson Scott Card series.
 * Grayson in the Honor Harrington stories was founded by the Church of Humanity Unchained, a sort of Space Amish cult that wanted to escape from the corrosive effects of technology. Unfortunately, unbeknownst to them, the planet they landed on had such high concentrations of heavy metals that they needed a very high level of technology to simply survive. They later went through a civil war and schism and sent out their own colony of religious dissenters to exile, who formed their own Cult Colony on the nearby planet of Masada.
 * Furthermore, Masada was not a Death World, and could have supported a Space Amish world as originally intended. (This irony was not lost on those who stayed behind- if they'd had the transport capacity to "exile" the majority to paradise instead of the fractious minority, they would have done so.) The schismatics were too determined to wipe out their brethren, however, to give up the high technology which was no longer necessary for survival, but to support an interstellar war machine.
 * Weber is quite fond of this trope. It crops up twice more in the Honorverse in the side stories. One is a relatively new colony formed from religious dissidents off Haven. Another crops up as part of the Tallbot Sector in much the same position as Grayson, though in this case its a local bug killing their crops and they were able to relocate to another habitable planet in the other half of their binary star system very early on. Unlike Grayson the current population is solidly atheist and rather bitter about their ancestors' fanaticism.
 * Another David Weber example is Pardal from Heirs of Empire; this is the variety that didn't start out fanatical, but became so after the interstellar civilization that founded it broke down. Specifically  The Safehold series is similar, but the anti-technology religion was artificially created to prevent the planet from being visible (due to radio emissions) to the genocidal alien Gbaba.
 * Several Robert A. Heinlein stories mention such colonies, such as that one planet mentioned in Friday where the Pope-in-Exile is allowed to openly celebrate mass.
 * At the end of Octavia Butler's Parable of the Talents, the second book in the "Parable" series, the followers of the new religion known as Earthseed (created by the main character, Lauren) go up in space to fulfill their "destiny", which is to establish a colony and "take root among the stars". One wonders how this would have progressed if she had gotten to write the scheduled third book.
 * Some of L. E. Modesitt, Jr.'s science fiction books use this along with divisions along racial lines, to the point where some characters begin confusing race with ideology. Most notable are The Parafaith War and The Ethos Effect, with the predominantly Caucasian "Revenants of the Prophet", which evolved out of a merging of Mormons and a white Muslim offshoot sect. The protagonist of The Parafaith War has to deal with strong suspicion about his motives and loyalties because he looks a lot like a generic Rev in a society whose population was mostly derived from south/east Asia.
 * In Lois McMaster Bujold's Ethan of Athos, the planet Athos was settled by a misogynistic religious order as an all-male colony. They used frozen eggs and artificial wombs to keep the population up. The inherent practical problems of maintaining a stable population on a planet where importing so much as a photograph of a woman involves considerable paperwork is the focus of the plot, and the Athosians are treated quite sympathetically by the standards of this trope.
 * Same deal in John Varley's Gaea Trilogy, only with neopagan lesbian separatists and frozen sperm.
 * Founding Fathers, a short story by Stephen Dedman, mentions several planets of this type, and is set on one settled by a bunch of people who were prepared to go to the trouble in order to live and raise their families on a planet with no black people.
 * In the Prince Roger series, one of the major characters is from a colony that was originally this. It was originally strict Roman Catholic, but then the witch hunts started and in the present day the main religion of the planet is Satanism of the Satan Is Good variety.
 * In Gordon R. Dickson's Childe Cycle (better known as the Dorsai books) the dawn of space colonization causes humanity to separate along philosphical lines (Faithholders, Warriors, Rationalists, Mystics, etc.)
 * The interstellar arks in Charles Sheffield's McAndrew stories include the "Amish Ark" of people seeking a low-tech life and the "Cyber Ark" of people dedicated to the development of AI.
 * Arthur C Clarke's Songs of Distant Earth mentions different religions, namely Mormons, Neo-Christians and Muslims, sending seedships in the generations before the End. It's implied that they may very well have succeeded.
 * In Sergey Lukyanenko's Genome, the entire population of the Ebon colony consists of the devout followers of the Church of the Angered Christ, which mandates that all aliens must be exterminated to make way for the "true children of God." To this end, they start breeding experts in torturing and killing aliens and building devastating weapons and ships. By the time The Empire decides to shut this nuthouse down in order to appease it's alien neighbors, the military strength of Ebon rivals the combined might of The Empire. However, no Ebonite will willingly kill a human, and their entire fleet is destroyed with only a few shots fired in response (mostly by nervous captains who immediately commit suicide). When humanity is threatened with an all-out war with their alien neighbors, the Emperor seriously considers letting the Ebonites loose in order to save The Empire. Thankfully, it never gets to that.
 * Sharon Shinn's Samaria series features a planet founded by Christians. There are genetically engineered humans with wings called angels, whose voices call out to a spaceship in the sky that runs the planet.
 * In C. J. Cherryh's Rider series, a group of fundamentalist Christians colonized what turned out to be a Death World due to the telepathic carnivores which use Jedi Mind Tricks to hunt humans. The colony can only survive due to some humans having a symbiotic relationship with the alien night horses, even though most of the colony regards the night horses as demonic and their human riders as a barely tolerated necessary evil.
 * The novel The Nineteenth Wife features the First Latter Day Saints, a fictional fundamentalist Mormon cult located in the (likewise fictional) town of Mesadale, Utah. The Firsts and Mesadale are closely modeled on the very real Fundamentalist Church of Jesus Christ of Latter Day Saints (also called the United Effort Plan or UEP) and Colorado City (formerly Short Creek), Utah.
 * The worshippers of the Holy Cows living aboard the generation ship in Bill the Galactic Hero on the Planet of Ten Thousand Bars. They venerate dairy products over all other food groups.
 * In a benign example, the Fox Cluster orbital colonies from 2081, a futurist book published 30 years ago, were founded by pacifists who wanted to establish a community so far away from civilization that it could never be threatened by war. Many of its founders were dedicated Quakers, although membership wasn't mandatory and nobody makes a big deal of this in the story.
 * Faction Paradox has the Remote, a group of colonists indoctrinated by corrupt Time Lords in an effort to convert them into effective shocktroopers. However, there were rather interesting effects when instead of being indoctrinated into a religion of any kind, said gentlemen used TV programs to control the colonists...

Live Action TV

 * The prison colony of Cygnus Alpha in the first season of Blakes Seven was ruled by a corrupt cult leader who enforced his control by controlling access to a "medicine" that protected against a divinely-sent plague. The disease was actually a minor environmental poison on that planet that quickly cleared itself, but since no one knew that, the cult members stayed in line and kept taking the drug.
 * Several planets in various Star Trek series may have qualified, Chakotay having hailed from one set up by Native Americans. Eh, once Sybok takes over, Nimbus III may qualify in Star Trek V the Final Frontier.
 * The colony in "The Way to Eden", if it had lasted long enough to properly be called a colony.
 * A preacher in The Outer Limits episode 'A New Life' led a group of followers to the woods to form a colony.

Web Original

 * The planet of New Tau Ceti in Associated Space was founded as a "pastoral enclave" by a religious movement that decided only humans could sin, so if humans became animals again, they could live without sin. So the cult members turned themselves into sheep. But the sheep still sometimes did stuff that would otherwise be considered sin, so the solution was that the sheep were blameless, but the shepherd had to pay the price for the actions of the sheep under their protection. Random visitors to the planet are thus conscripted as shepherds and forced to fight for their lives in an arena against a genetically-engineered super wolf. If they do well enough, they have defeated sin, and may depart in peace. If they die, well, they've paid the price for sin, as is only proper.
 * Tech Infantry has the Christian Federation, who turn themselves into this as part of their rebellion against the Earth Federation. Eventually they are crushed with the help of a force of volunteer Jewish mercenaries, who build themselves a Cult Colony called New Israel on the ruins of the former Christian Federation planets.
 * The aptly named Colony from We're Alive.

Video Games

 * In the Elite series of space-exploration games, there's a small colony in the van Maanen's star system, not far from Earth, which is home to an extremist cult of religious types. Rather than the usual pastoral approach, they live in underground caverns and mine for gemstones by hand, exporting the gems to buy the bare necessities for survival on the hostile planet. A very popular stop, both due to the gemstone exports (albeit at very low ammounts) and the HUUUGE ammount of 'Illegal Goods' you can smuggle in there from nearby star-systems at a healthy profit.
 * Mass Effect has a mission where Shepard has to infiltrate a colony controlled by the cultists and abduct their leader.
 * In EVE Online, the Amarr Empire is descended from a colony established by a fringe Catholic sect called the Conformists. Later on, the Blood Raiders flee the Amarr empire and into deep space in order to practice their religion in relative peace.
 * Infinite Space has nation of Adis, which forbids people from traveling to space.
 * In Fallout: New Vegas, the Bright Brotherhood wants to use rockets to blast their way to space to find a place where they won't be persecuted. The player can either help them or sabotage their flight so that the rockets blow up. The Distant Finale shows.

Real Life

 * The Pilgrims, best remembered for inspiring the Thanksgiving Day holiday, were largely members of a separatist faction of the Church of England. Fed up with being persecuted by more moderate factions, they left Britain for the Netherlands, which had much the same reputation then as now, but at least didn't persecute people for disagreeing with the Archbishop of Canterbury. In 1620, some of the separatists, afraid that their children were assimilating into Dutch society and losing their English identity, booked the freighter Mayflower to found Plymouth in what is today Massachusetts. They were originally planning to settle in the existing colony of Jamestown, Virginia, but were blown off course.
 * In 1630, members of another breakaway sect known as the Puritans founded the Massachusetts Bay Colony forty miles north of Plymouth, establishing the city of Boston. They promptly made it illegal to be anything but a Puritan, and soon were expelling large numbers of their own members for not being sufficiently Puritan, which is how the nearby colonies of Rhode Island and Connecticut got started.
 * One of the groups expelled from Massachusetts Bay Colony settled down in Rhode Island, where they promptly began expelling each other over disagreements. Eventually, everyone was gone except the preacher and his wife, who then had an argument, declared each other heretics, and excommunicated each other. Just in case you were wondering why the Puritans kicked them out...
 * The Mormons fled persecution in Illinois and Missouri by packing up and heading to Utah, then part of Mexico and inhabited only by Natives. In 1890, the Mormon leadership agreed to ban polygamy, opening a path for statehood and an end to official persecution. A few refused to accept this and began founding their own towns in other nearby states, territories and countries where they could practice their polygamous lifestyle in relative peace. Some such towns are still going strong today, with polygamy still going on.
 * On a darker note, charismatic preacher Jim Jones founded his own colony, Jonestown, with around a thousand followers in Guyana. It ended badly.
 * The modern nation of Israel was established in order for the Jews to escape persecution in Europe. The area they picked out was also their ancient ancestral homeland, subverting this trope to a degree. Also partially averted in that they welcome people who don't follow their beliefs to the extent that there have been periodic worries that the majority will someday be non-Jewish, though there are some restrictions on that for "the legal code was written by Holocaust survivor Shell Shocked Veterans" reasons.