Sci-fi subreddits
We found 114 active sci-fi subreddits: communities with at least one new post a day on average in September 2026, ranked by members. The largest is r/StarWars with 4.7M members. The busiest is r/transformers, with 7,438 posts last month. In 8 of the 69 we could measure, a brand-new account's post usually stays up: they remove 17% or fewer of posts from accounts under a week old.
Data for 114 communitiesDownload CSV
Filter it by your account age and karma, the audience you want and the best time to post.
- r/StarWars4.7M members
- r/transformers7,438 posts in September 2026
- r/StrangerThingsMemes+78% members in 12 months
- r/FalloutTVseries12% of new-account posts removed
All active sci-fi subreddits, by members
| # | Subreddit | Members | Posts / month | Member growth, 12 mo | Median author age | Women | Posts with a reply | New-account posts removed | Links |
|---|---|---|---|---|---|---|---|---|---|
| 1 | r/StarWars↗Unofficial community for Star Wars, an American epic space opera franchise, created by George Lucas and centered around a film series that began with the eponymous 1977 movie. | 4.7M | 2,111 | +4% | 29 | 13% | 84% | Min. age/karma | Yes |
| 2 | r/scifi↗Welcome to r/scifi, a home for all things science fiction, the heart of speculative fiction. Join the discussion about your favorite books, authors, movies, shows, comics, and games — anything with a | 4.51M | 717 | +2% | 36 | 16% | 77% | Min. age/karma | Yes |
| 3 | r/PrequelMemes↗Memes of the Star Wars Prequels. | 3.82M | 390 | +1% | 25 | 13% | 96% | Min. age/karma | Yes |
| 4 | r/StrangerThings↗Sub for the Netflix Original series: Stranger Things. The disappearance of a young boy sparks a chain of events leading the residents of the small town of Hawkins to uncover a government conspiracy a | 2.79M | 717 | +12% | 28 | 33% | 94% | 90% | Yes |
| 5 | r/startrek↗A casual, constructive, and most importantly, welcoming place on the internet to talk about Star Trek | 1.06M | 1,176 | +4% | 36 | 20% | 91% | 99% | Yes |
| 6 | r/doctorwho↗Reddit's Doctor Who Fan Community - News, Discussion, Artwork and Fan Creations! | 1.02M | 1,017 | +3% | 29 | 31% | 82% | 97% | Yes |
| 7 | r/westworld↗Subreddit for the HBO series Westworld. | 990K | 58 | +1% | 29 | 21% | 75% | – | Yes |
| 8 | r/AskScienceFiction↗**It's like Ask Science, but all questions and answers are written with answers gleaned from the universe itself.** Use in-universe knowledge, rules, and common sense to answer the questions. Or as ** | 894K | 773 | +3% | 29 | 15% | 100% | Min. age/karma | No |
| 9 | r/Avatar↗The home of Avatar on Reddit! Your source for news, art, comments, insights and more on the beautiful and dangerous world of Pandora. Meet fellow Avatar fans and discuss the films, games, novels, comi | 777K | 575 | +9% | 26 | 33% | 93% | 93% | Yes |
| 10 | r/dune↗Dune is a landmark science fiction novel first published in 1965 and the first in a 6-book saga penned by author Frank Herbert. Widely considered one of the greatest works within the sci-fi genre, Dun | 668K | 428 | +6% | 31 | 16% | 31% | 100% | Yes |
| 11 | r/TheMandalorianTV↗The Mandalorian is a space Western and the first live-action series in the Star Wars franchise streaming on Disney+ | 655K | 158 | +2% | 29 | 16% | 97% | 100% | Yes |
| 12 | r/starwarsmemes↗The home for ALL Star Wars memes! | 590K | 338 | +3% | 28 | 14% | 54% | 99% | Yes |
| 13 | r/TheHandmaidsTale↗This subreddit is a place to discuss the TV series of both The Handmaid's Tale and The Testaments, based on Margaret Atwood's novels of the same name. Blessed be the fruit. | 527K | 118 | +3% | 31 | 78% | 89% | Min. age/karma | Yes |
| 14 | r/blackmirror↗Black Mirror on Netflix To get more information about Season 7 - visit our Discord: https://discord.gg/6U5SshM | 508K | 160 | +4% | 27 | 34% | 73% | Min. age/karma | Yes |
| 15 | r/SequelMemes↗Memes of the Star Wars Sequels | 467K | 42 | +1% | 26 | 13% | – | 21% | Yes |
| 16 | r/StarWarsLeaks↗Production Leaks, Spoilers, Rumors & News from future Star Wars media. | 427K | 48 | +2% | 28 | 13% | 83% | 98% | Yes |
| 17 | r/Hungergames↗This community is devoted to the world of the Hunger Games, a series of books by Suzanne Collins and hit movie adaptations. | 368K | 1,111 | +17% | 26 | 70% | 87% | 71% | Yes |
| 18 | r/transformers↗This is a family-friendly community for all things Transformers -- mostly the toys, but also the cartoons, movies, and comics. | 365K | 7,438 | +36% | 26 | 15% | 74% | Min. age/karma | Yes |
| 19 | r/StarWarsEU↗Welcome to the **Star Wars Expanded Universe** subreddit! We are primarily a source of discussion and news surrounding the Star Wars LEGENDS and STORY GROUP CANON Expanded Universe Stories. If you wa | 348K | 358 | +6% | 29 | 12% | 85% | 76% | Yes |
| 20 | r/GODZILLA↗Welcome to /r/GODZILLA, a place to admire the King of the Monsters and his many foes! If you haven't already, please read through the rules and our FAQ before posting. | 333K | 2,922 | +14% | 28 | 14% | 85% | Min. age/karma | Yes |
| 21 | r/sciencefiction↗This reddit is for fans and creators of Science Fiction and related media in any form. SF topics should involve plausible ideas reached through the rational application of science. General speculative | 320K | 342 | +14% | 37 | 15% | 63% | 54% | Yes |
| 22 | r/LV426↗for all things Alien and Predator. | 316K | 578 | +10% | 34 | 14% | 85% | Min. age/karma | Yes |
| 23 | r/Mandalorian↗𝐎𝐥𝐚𝐫𝐨𝐦! (𝐖𝐞𝐥𝐜𝐨𝐦𝐞!) Here we focus on all things Mandalorian; whether that’s culture, lore, language, all who are curious are welcomed. This is the way! | 272K | 125 | +2% | 29 | 16% | 88% | Min. age/karma | Yes |
| 24 | r/starwarsspeculation↗Star Wars Speculation is a community dedicated to speculative discussion of the Star Wars franchise. It is a curated space to talk about additions to canon in a larger perspective — incorporating info | 265K | 37 | +3% | 28 | 13% | 98% | 76% | Yes |
| 25 | r/TheExpanse↗Subreddit for the Sci Fi space opera franchise, The Expanse. Which include the Prime video TV series, the book series by James S.A Corey, Comics, and Games. | 262K | 265 | +9% | 34 | 16% | 71% | 91% | Yes |
| 26 | r/StarWarsCantina↗A place to discuss Star Wars with an emphasis on positivity. Constructive criticism of any content is allowed, but do so respectfully towards the creators as well as the fans. The Cantina is here fo | 230K | 356 | +13% | 30 | 14% | 82% | 99% | Yes |
| 27 | r/MawInstallation↗A subReddit dedicated to in-depth discussion of the Star Wars franchise with an emphasis on in-universe lore. Named after Grand Moff Tarkin's secret Imperial Research Center, from Legends, where the | 230K | 178 | +6% | 29 | 12% | 95% | Min. age/karma | No |
| 28 | r/DarK↗A subreddit for the Netflix sci-fi thriller series Dark. When two children go missing in a small German town, its sinful past is exposed along with the double lives and fractured relationships that ex | 226K | 145 | +9% | 28 | 33% | 100% | 100% | Yes |
| 29 | r/Stargate↗All things dedicated to the 1994 Stargate movie and the MGM franchise: SG-1, Atlantis, Universe, Origins, video, RPG games and everything else. | 211K | 702 | +18% | 35 | 19% | 91% | 17% | Yes |
| 30 | r/JurassicPark↗Everything related to Jurassic Park and the franchise. We talk about the films, books, toys, and more. Fan ran. | 208K | 479 | +15% | 31 | 19% | 74% | Min. age/karma | Yes |
Show all 114 subreddits
| # | Subreddit | Members | Posts / month | Member growth, 12 mo | Median author age | Women | Posts with a reply | New-account posts removed | Links |
|---|---|---|---|---|---|---|---|---|---|
| 31 | r/andor↗Andor is a Star Wars series that follows the formative years of Rebel spy Cassian Andor in a prequel to Star Wars: Rogue One. Streaming on Disney+. | 206K | 370 | +15% | 34 | 15% | 93% | 62% | Yes |
| 32 | r/firefly↗/r/Firefly, for all your Sci-Fi western needs. The Reddit for everything in the Verse! Can't stop the signal. Shiny. | 183K | 115 | +14% | 36 | 23% | 88% | – | Yes |
| 33 | r/starwarsrebels↗The Reddit home for the Star Wars Rebels animated TV show. | 179K | 60 | +5% | 27 | 16% | 82% | Min. age/karma | Yes |
| 34 | r/startrekmemes↗Memes of the Star Trek franchise | 162K | 487 | +10% | 36 | 20% | 84% | 96% | Yes |
| 35 | r/Fotv↗Official Fallout Network subreddit for discussion of the Fallout Amazon Prime Series, from Kilter Films and Amazon Studios | 162K | 44 | +30% | 31 | 18% | 75% | 56% | Yes |
| 36 | r/gallifrey↗News and in-depth discussion of everything Doctor Who. | 160K | 232 | +5% | 29 | 28% | 69% | 97% | Yes |
| 37 | r/DoctorWhumour↗A subreddit for all lighthearted Doctor Who related content and discussion :) | 152K | 400 | +7% | 27 | 29% | 84% | 95% | Yes |
| 38 | r/clonewars↗A subreddit to discuss anything about Star Wars: The Clone Wars, whether that be the two TV shows, The Bad Batch, or the event itself. Reddit-wide rules apply. | 143K | 516 | +20% | 25 | 14% | 83% | 17% | Yes |
| 39 | r/bladerunner↗A subreddit dedicated to Blade Runner and Blade Runner 2049. The 1982 dystopian science fiction action film directed by Ridley Scott and starring Harrison Ford, Rutger Hauer, and Sean Young - and it’s | 141K | 183 | +11% | 32 | 11% | 65% | 92% | Yes |
| 40 | r/CloneWarsMemes↗Memes of Star Wars: The Clone Wars | 132K | 30 | +7% | 22 | 15% | – | Min. age/karma | Yes |
| 41 | r/interstellar↗Welcome to the subreddit dedicated to the movie Interstellar! | 126K | 152 | +15% | 30 | 18% | 75% | Min. age/karma | Yes |
| 42 | r/saltierthancrait↗Saltier Than Crait is a place for Star Wars fans to engage in conversations about the current state of the franchise. | 124K | 81 | +5% | 30 | 11% | 71% | 100% | Yes |
| 43 | r/SiloSeries↗/r/SiloSeries is the subreddit for news and discussion of Silo, the post-apocalyptic television show on Apple TV+. For discussion of the WOOL series of books written by Hugh Howey, visit /r/wool. | 123K | 1,645 | +46% | 36 | 31% | 91% | – | Yes |
| 44 | r/StrangerThingsMemes↗Friends don’t lie, but they do post memes. Welcome to the ultimate destination for everything Stranger Things humor. From Steve's hair to Vecna's clock, we’re stuck in the Upside Down and we’re never | 111K | 34 | +78% | 30 | 34% | 48% | 92% | Yes |
| 45 | r/matrix↗The world's biggest online community about The Matrix franchise, created by the visionary minds of Lana and Lilly Wachowski! Welcome to the Source! | 110K | 250 | +23% | 35 | 11% | 73% | 29% | Yes |
| 46 | r/DeepSpaceNine↗The subreddit for everything Star Trek: Deep Space Nine! Feel free to post pics, videos, articles, your opinions & questions... anything to do with the show or the actors. | 105K | 269 | +18% | 38 | 22% | 93% | – | Yes |
| 47 | r/TheOrville↗Set 400 years in the future, the crew of the U.S.S. Orville continue their mission of exploration, navigating both the mysteries of the universe, and the complexities of their own interpersonal relati | 105K | 77 | +9% | 34 | 20% | 84% | – | Yes |
| 48 | r/StarWarsAhsoka↗An upcoming Star Wars series starring Rosario Dawson as Ahsoka Tano, set within the timeline of The Mandalorian. | 104K | 75 | +4% | 32 | 14% | 90% | – | Yes |
| 49 | r/BacktotheFuture↗Welcome to r/BacktotheFuture! Your Reddit source for all things Back to the Future since 2009! Feel free to participate in our friendly and welcoming community. | 102K | 266 | +25% | 38 | 13% | 92% | 99% | Yes |
| 50 | r/The100↗🐬 | 100K | 87 | +4% | 25 | 44% | 49% | 98% | Yes |
| 51 | r/DaystromInstitute↗Serious, in-depth discussion about Star Trek. Nominate posts and comments as Exemplary Contributions by replying with "M-5, nominate this." | 100K | 48 | +4% | 34 | 16% | 100% | – | No |
| 52 | r/StarWarsCirclejerk↗You will never find a more wretched hive of unoriginal tier lists and vaguely horny glup shitto-posting. | 87K | 928 | +50% | 30 | 13% | 86% | 41% | Yes |
| 53 | r/PlanetOfTheApes↗Reddit for Apes — news, analysis, theories, discussion, podcasts and more, including the upcoming Disney era beginning with Wes Ball’s film (2024). Apes will Rise! | 86K | 41 | +5% | 28 | 15% | 43% | 97% | Yes |
| 54 | r/RedDwarf↗The official subreddit of Red Dwarf, the cult sci-fi comedy show! | 83K | 177 | +18% | 39 | 19% | 92% | 95% | Yes |
| 55 | r/JurassicMemes↗Memes, uh, find a way | 80K | 48 | +8% | 26 | 17% | 90% | 100% | No |
| 56 | r/TheOA↗Subreddit for the works of Brit Marling and Zal Batmanglij such as The OA, A Murder At the End of the World, Another Earth, Sound of My Voice, The East, and The Recordist | 76K | 114 | +8% | 30 | 50% | 90% | – | Yes |
| 57 | r/BSG↗/r/BSG has gone private in protest of recent API changes. So Say We All | 75K | 127 | +17% | 37 | 18% | 90% | 84% | Yes |
| 58 | r/TNG↗The subreddit for everything Star Trek: The Next Generation! Feel free to post pics, videos, articles, your opinions & questions... anything to do with the show or the actors. | 75K | 305 | +30% | 41 | 17% | 88% | Min. age/karma | Yes |
| 59 | r/predator↗For fans of the intergalactic bad-ass hunter of the science fiction horror film series, games and comics. Dark Mode recommended. | 70K | 271 | +62% | 32 | 12% | 76% | Min. age/karma | Yes |
| 60 | r/ForAllMankindTV↗For All Mankind is a science fiction television series on Apple TV+. It depicts an alternate history where the Soviets complete the first manned Moon landing and the Cold War-era space race never ende | 69K | 105 | +29% | 35 | 21% | 100% | – | Yes |
| 61 | r/ShittyDaystrom↗The Shitty Daystrom Research Institute is a shitty subreddit dedicated to shitty discussion of everything and anything related to the Star Trek franchise. This subreddit is owned and operated by the | 64K | 717 | +23% | 39 | 17% | 95% | Min. age/karma | Yes |
| 62 | r/starwarscanon↗Welcome to r/StarWarsCanon a place to discuss the current Canon of Star Wars and related media. | 64K | 34 | +22% | 30 | 11% | 66% | Min. age/karma | Yes |
| 63 | r/saltierthankrayt↗r/SaltierThanKrayt is a subreddit for discussion of the current state of the STAR WARS fandom (and other big franchises), with an emphasis of criticizing and calling out the toxicity and bigotry withi | 61K | 508 | +15% | 29 | 17% | 87% | Min. age/karma | Yes |
| 64 | r/FalloutTVseries↗new-account friendlySubreddit for all discussions about the Amazon Prime Fallout Series. Feel free to talk about your thoughts and what you want to see in Season 3 of Fallout TV Show! Icon art by u/Much-Magazine4092 | 61K | 34 | +126% | 32 | 20% | 86% | 12% | Yes |
| 65 | r/FoundationTV↗A place to discuss the Apple TV+ adaptation of Isaac Asimov's Foundation series. Respect and enjoy the peace. | 61K | 54 | +13% | 36 | 22% | 90% | Min. age/karma | Yes |
| 66 | r/tron↗Greetings, Programs. Welcome to the grid. | 60K | 248 | +19% | 31 | 13% | 86% | – | Yes |
| 67 | r/StarTrekStarships↗A subreddit for lovers of Star Trek starships. Anything related to the ships of Star Trek welcome, art, toys, models, behind the scenes, etc. * **[Be Sure To Read The Rules!](https://www.reddit.com/r | 57K | 324 | +29% | 40 | 10% | 99% | Min. age/karma | Yes |
| 68 | r/StarWarsShips↗new-account friendlyPostings of images of famous, infamous and non-famous ships from the Star Wars Universe, complete with data (if available) from canon sources. | 57K | 376 | +33% | 31 | 10% | 89% | 14% | Yes |
| 69 | r/thebadbatch↗Welcome to the subreddit for The Bad Batch - the Star Wars television series centered around its namesake squad of extraordinary clone commandos, set in the aftermath of the Clone War. | 57K | 36 | +12% | 25 | 18% | 85% | 97% | Yes |
| 70 | r/PacificRim↗A place for anything related to Pacific Rim. Post anything Pacific Rim from toys to movies, games to trailers, anything and everything Pacific Rim belongs here. There's space for Jaegers and Kaiju ali | 55K | 201 | +28% | 24 | 14% | 90% | 100% | Yes |
| 71 | r/voyager↗Welcome to the official (technically) Star Trek: Voyager subreddit! This subreddit exists so that we fans of the show can talk about it and its characters and themes! This is an inclusive, safe enviro | 53K | 241 | +37% | 39 | 24% | 92% | 82% | Yes |
| 72 | r/babylon5↗Discussion of all things Babylon 5 | 52K | 210 | +21% | 41 | 17% | 92% | 98% | Yes |
| 73 | r/starwarsblackseries↗new-account friendlyA subreddit about our love of Hasbro's Star Wars The Black Series. | 49K | 480 | +21% | 28 | 9% | 83% | 14% | Yes |
| 74 | r/Star_Trek_↗Welcome to Star Trek! We are a sub for Trek fans to discuss likes and dislikes, canon connections, humor, and any other Trek ideas you want to talk about. Qapla'! | 47K | 435 | +70% | 42 | 14% | 63% | Min. age/karma | Yes |
| 75 | r/fringe↗Fan community for the TV show "Fringe," starring Anna Torv, Joshua Jackson, and John Noble, which aired from 2008 to 2013. "When you open your mind to the impossible, sometimes you find the truth." — | 47K | 85 | +20% | 35 | 36% | 86% | – | Yes |
| 76 | r/Picard↗Whether related to the show or the man, this is the place for all things PICARD! | 46K | 72 | +15% | 40 | 18% | 74% | Min. age/karma | Yes |
| 77 | r/okbuddyseverance↗new-account friendlyDAE enjoy each shitpost equally??? Ortbo’s palace awaits us all the ONLY subreddit devoted to serious discussion of the erotically avant garde Tim Apple series Severance no AI content allowed | 46K | 62 | +14% | 31 | 37% | 93% | 5% | Yes |
| 78 | r/maninthehighcastle↗This subreddit is for the Amazon TV show The Man In The High Castle | 46K | 39 | +14% | 29 | 20% | 82% | – | Yes |
| 79 | r/risa↗JUSTICE FOR LOWER DECKS | 39K | 90 | +15% | 36 | 20% | 82% | – | Yes |
| 80 | r/Treknobabble↗reddit... the front page of the internet. These are the posts of the subreddit /r/Treknobabble. Its continuing mission: to explore strange new content and old favourites, to seek out new readers and o | 37K | 64 | +7% | 37 | 18% | 78% | – | Yes |
| 81 | r/starshiptroopers↗/r/StarshipTroopers is a fan subreddit devoted to the novel *Starship Troopers* by Robert A. Heinlein, the 1997 film adaptation, sequels, and other material. **Do you have what it takes to be a Citiz | 36K | 53 | +30% | 36 | 8% | 76% | Min. age/karma | Yes |
| 82 | r/StarTrekTNG↗Star Trek: The Next Generation | 35K | 164 | +39% | 43 | 16% | 77% | – | Yes |
| 83 | r/ResidentAlienTVshow↗This subreddit is for the Resident Alien TV show on SyFy starring Alan Tudyk about an alien who crash lands on Earth and goes undercover as a small town doctor while trying to complete his mission. | 35K | 61 | +18% | 38 | 49% | 91% | 49% | Yes |
| 84 | r/StarWarsTheories↗Discussions of various fan theories, questions, and alternate timelines about Star Wars | 34K | 36 | +9% | 29 | 12% | – | – | No |
| 85 | r/CISDidNothingWrong↗Join the fight for independence from the corruption of the Republic! | 34K | 51 | +17% | 24 | 14% | 80% | Min. age/karma | Yes |
| 86 | r/LowerDecks↗An unofficial fan community dedicated to discussion and news about Star Trek: Lower Decks. | 33K | 109 | +41% | 38 | 22% | 95% | – | Yes |
| 87 | r/jurassicworld↗new-account friendlySubreddit for discussing Jurassic World content | 32K | 218 | +42% | 29 | 17% | 66% | 15% | Yes |
| 88 | r/fifthelement↗Welcome to the biggest Fifth Element community on Reddit! Whether you're here for news, deep dives, wild theories, or just to celebrate this cult sci-fi classic, you’re in the right place. With the 3 | 28K | 54 | +63% | 41 | 12% | 83% | – | Yes |
| 89 | r/kaiju↗ From ancient Titans to prehistoric beasts, humanity's fascination with giant monsters has led to the creation of literary, artistic, and cinematic works about creatures that transcend established nat | 28K | 251 | +38% | 31 | 12% | 40% | 91% | Yes |
| 90 | r/StrangeNewWorlds↗A spoiler-friendly place to discuss the TV series Star Trek: Strange New Worlds | 27K | 463 | +15% | 41 | 25% | 87% | – | Yes |
| 91 | r/StarWars_↗A community for respectful, constructive, and non-toxic discussion about all things Star Wars. | 27K | 196 | +205% | 33 | 10% | 93% | Min. age/karma | Yes |
| 92 | r/byler↗This is a subreddit dedicated to the ship Byler (Mike Wheeler x Will Byers) from the Netflix Original Series Stranger Things! This sub is for discussing the ship and subjects directly related to it, | 26K | 106 | +449% | 23 | 62% | 79% | 88% | Yes |
| 93 | r/tos↗/r/TOS is for all topics relating to Star Trek: The Original Series (plus TAS and the original films). | 22K | 138 | +57% | 46 | 15% | 89% | 88% | Yes |
| 94 | r/ahsokatano↗Everything pertaining to Ahsoka Tano: Order 66, Images, Fan Art, Stories, Video Clips and much more. | 21K | 41 | +19% | 30 | 21% | – | – | Yes |
| 95 | r/MazeRunner↗new-account friendlySubreddit dedicated to the book & film series "The Maze Runner" by James Dashner, its sequel series "The Maze Cutter" and all books and content related to this universe. | 20K | 74 | +21% | 20 | 46% | 100% | 12% | Yes |
| 96 | r/DoctorWhoNews↗A subreddit dedicated to news and discussion about the TV show "Doctor Who" Historically Doctor Who has been "woke". It's always been a mirror reflecting the societal changes that are occurring. Hat | 19K | 44 | +22% | 32 | 23% | 86% | 82% | Yes |
| 97 | r/StarWarsBlogs↗You will never find a more wretched hive of scum and villainy. | 19K | 99 | +8% | 34 | 9% | 61% | – | Yes |
| 98 | r/TheJediPraxeum↗Hello! And welcome to The Praxeum! This is a place for fans of Star Wars Legends (otherwise known as the Expanded Universe) to come together and discuss the rich lore and history they love, without me | 19K | 100 | +72% | 30 | 10% | 81% | – | Yes |
| 99 | r/SciFiScroll↗News, updates, trailers, discussions & more relating to science fiction, fantasy, horror, straight science, and more. We welcome you to post stories that you believe will be of interest to the communi | 18K | 122 | +13% | 38 | 10% | 22% | – | Yes |
| 100 | r/ReBoot↗A place to discuss Mainframe Entertainment's groundbreaking CGI TV show: ReBoot. | 17K | 52 | +29% | 36 | 18% | 82% | – | Yes |
| 101 | r/reylo↗new-account friendlyThis subreddit is dedicated to Reylo, the ship between Rey and Kylo Ren from the Star Wars fandom. | 16K | 147 | +12% | 28 | 79% | 71% | 6% | Yes |
| 102 | r/doctorwhocirclejerk↗new-account friendlyThis is the place for real discussion of Doctor Who. This means that your cupboards, toys, needlework, bad wolf graffiti, doors, cakes and cosplay are the only things allowed to be posted. David Tenn | 15K | 77 | +8% | 23 | 28% | 82% | 16% | Yes |
| 103 | r/50s_science_fiction↗A community for all things related to science fiction films of the 50s. It truly is the SUPREME EXCITEMENT OF OUR TIME! | 14K | 106 | +65% | 54 | 12% | 86% | – | Yes |
| 104 | r/enterprise↗About the television show 'Star Trek: Enterprise.' Follow the adventures of Captain Jonathan Archer (the best captain) and the crew of the NX-01, Earth's first warp 5 class starship. | 14K | 98 | +96% | 41 | 15% | 91% | – | Yes |
| 105 | r/ClassicTrek↗An unofficial fan community dedicated to discussion and news about the "classic" Star Trek series: TOS, TAS, TNG, DS9, VOY, and ENT, plus all the movies. (As well as their affiliated merchandise, vid | 13K | 175 | +156% | 43 | 13% | 82% | – | Yes |
| 106 | r/prequelappreciation↗A sub to seriously discuss the Star Wars Prequels, as well as related media, and to recognize the trilogy's very best qualities. | 12K | 81 | +128% | 33 | 10% | 75% | – | Yes |
| 107 | r/trektalk↗News, Reviews, and Commentary on all things Star Trek. Fascinating and Thought-provoking. All opinions welcome. | 12K | 276 | +126% | 42 | 13% | 80% | Approved only | Yes |
| 108 | r/12Monkeys↗/r/12Monkeys is the unofficial subreddit for discussion of all things 12 Monkeys including the 1995 film and the 2015-2018 TV series. | 11K | 70 | +20% | 33 | 30% | 85% | – | Yes |
| 109 | r/TheSequels↗A place to discuss and highlight some of the best moments, places and characters from The Star Wars Sequel Trilogy era (including the movies, the shows like Star Wars Resistance and The Mandalorian, n | 11K | 88 | +70% | 32 | 13% | 99% | – | Yes |
| 110 | r/SciFiNews↗Science Fiction / Sci-Fi / SciFi - The Last of Us, The Expanse, Fallout, Silo, Monarch, For All Mankind, The Peripheral, Westworld, Terminator, Avatar, Dune, Planet of the Apes, Star Trek, Star Wars, | 9.1K | 167 | +455% | 40 | 8% | 57% | – | Yes |
| 111 | r/TheDeepCore↗ An Empire united in its common interest of preserving and appreciating what we see as being the True SW Expanded Universe. | 8.1K | 41 | +20% | 26 | 14% | 87% | – | Yes |
| 112 | r/Thunderbirds↗A place to discuss Gerry and Sylvia Anderson's cult puppet show and related media. | 8K | 58 | +39% | 35 | 14% | 81% | – | Yes |
| 113 | r/BigFinishProductions↗Unofficial - but enthusiastic - subreddit for Big Finish Productions discussions, news, reviews, covers, fanworks, and more. Posts about Big Finish's work both within and outside the "Doctor Who" univ | 5.3K | 116 | +44% | 30 | 22% | 91% | – | Yes |
| 114 | r/Godzilla1998↗This is a community dedicated to those that are also fans of the Godzilla 1998 film. Any kind of content about the film, cartoon series, cast, crew, production, fanart, posters, merch, etc is welcome | 5K | 65 | – | 30 | 13% | 82% | – | Yes |
Looking for a ranking by size and growth? Top sci-fi subreddits by tier.
How this list is built
Subreddits are grouped into topics by what their posts are about; this list holds the sci-fi group. We include subreddits that are safe for work and had at least 30 new posts in September 2026, about one a day.
Members is Reddit's subscriber count; growth compares it with a year earlier. Posts with a reply is the share of posts that got at least one comment over the last three months. Median author age and women are estimated from what authors say about themselves, and shown only when enough of them did. New-account posts removed is the share of posts from accounts younger than 7 days that were removed; communities at or below 17% are marked new-account friendly. Min. age/karma means the subreddit asks for a minimum account age or karma before you can post.
The list is rebuilt every month from public Reddit posts and comments. Data and CSV are free to reuse under CC BY 4.0 with a link to this page.
Sci-fi subreddits: common questions
What is the biggest sci-fi subreddit?
r/StarWars, with 4.7M members in September 2026. Next are r/scifi (4.51M) and r/PrequelMemes (3.82M).
Which sci-fi subreddits are the most active?
By posts in September 2026: r/transformers (7,438 posts), r/GODZILLA (2,922 posts) and r/StarWars (2,111 posts).
Which sci-fi subreddits can a new account post in?
r/FalloutTVseries (12% of new-account posts removed), r/StarWarsShips (14% of new-account posts removed) and r/starwarsblackseries (14% of new-account posts removed). They ask for no minimum karma or account age, and most posts from accounts under a week old stay up.
How often is this list updated?
Every month, when we rebuild our subreddit data. This version uses data for September 2026. Member counts come from Reddit; activity, removals and who writes come from public Reddit posts and comments.
Find the subreddits that fit your post
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