Best sci-fi TV shows of all time

The X Files_20th Century Fox Television_HERO IMAGE for best sci-fi TV shows
(Image credit: 20th Century Fox Television)

When a sci-fi concept is brought to life on TV, there’s a lot of opportunity to succeed, expand, and delight viewers with multiple seasons, recurring cast members, and dedicated writers. Sometimes, TV shows don’t get that lucky, getting canceled before they’ve had a chance to truly shine. But, that doesn’t mean they don’t deserve a place on our list. Earning cult status as a TV show is just as impressive.

Whether it’s ten seasons or one, the beauty of a TV show spanning multiple episodes means there’s hours upon hours to get creative. And, with the sci-fi genre, the possibilities are seemingly endless. Whatever weird, wonderful, and wacky ideas that can be dreamt up and pitched to the right people mean viewers eventually get a chance to experience these alternate realities from the minds of geniuses.

Our list of the best sci-fi TV shows of all time spans decades, explores galaxies, tests limits, and in some cases may even divide opinion, but we promise to explain why each of our 15 picks deserves its place here. 

Whilst the best sci-fi movies get a feature-length slot on the big screen, sci-fi TV shows must captivate the viewer for hours on end, enticing them to watch every episode whether anthology-based or an episodic timeline. Our list contains a little something for everyone. And, if you’re in the market for more sci-fi greatness, feel free to explore our best space movies and best space horror movies when you’re done.

15. The Outer Limits

Screenshot from the TV show The Outer Limits (1963)

(Image credit: Villa Di Stefano)
  • Released: September 16, 1963
  • Seasons: 2
  • Cast: Bob Johnson, Ben Wright, William Douglas

The Outer Limits only ran for two seasons, but boy, was it great. Given that it was broadcast around the same time as The Twilight Zone, it had a challenge on its hands and it stepped up to the plate. 

This show still holds fast as a great and gruesome anthology series that brought twisted sci-fi tales to TV screens in the 60s. There was a modern revival in the 90s that ran a little more successfully with seven seasons under its belt, but it wouldn’t have had a chance if the original hadn’t set the tone.

Iconic episodes include “Cold Hands, Warm Heart” featuring William Shatner as an astronaut returning to Earth suffering from recurring nightmares to “Demon with a Glass Hand” as a man is linked to a future war via the computer hidden inside his glass hand. The Outer Limits stretched the sci-fi TV genre to try out almost unthinkable things and warp viewers grasp on reality.

14. Firefly

Adam Baldwin, Nathan Fillion, Ron Glass, Sean Maher, Jewel Staite, Gina Torres, Alan Tudyk, Morena Baccarin, and Summer Glau in Firefly (2002)_Universal Pictures

(Image credit: Universal Pictures)
  • Released: September 20, 2002
  • Seasons: 1
  • Cast: Nathan Fillion, Gina Torres, Alan Tudyk

Set in the year 2517, the crew on the ship Serenity fight to survive following a universal civil war that’s thrown the galaxy into unrest. In a battle to keep fed and in flight, the team must find themselves work across the universe whilst also dealing with internal conflict and challenges.

Originally hoping to run for seven years, Firefly was canceled after just one season due to low ratings. That said, perhaps it wasn’t the time for a sci-fi show like this in 2002. But, in 2005, writer/director Joss Whedon did continue his tale in feature-length movie Serenity that was met with rave reviews. 

The original show has earned itself cult status over the years from fans who still enjoy the 14 episodes that did make it to the small screen. Find all the episodes here on our Firefly streaming guide.

13. Babylon 5

Screenshot from the TV show Babylon 5.

(Image credit: Warner Bros. Television)
  • Released: January 26, 1994
  • Seasons: 5
  • Cast: Mira Furlan, Richard Biggs, Stephen Furst

Much like its name, Babylon 5 is set onboard a five-mile-long spaceship floating in neutral territory and is set across five years of political unrest, tensions, and wars. And, it ran for five seasons. That’s a lot of fives.  

Aboard the ship reside humans and aliens alike, all on a mission to sort through their differences, rather than compete. A welcome change to your usual sci-fi action-packed conflict between Earth and other planets.

During its time on screen, it depicted a truly memorable sci-fi saga from beginning to end that encapsulates its motto that Babylon 5 is the “last, best hope for peace.” This epic TV show is a slow burn, but one that keeps viewers intrigued at the possibility of composure between warring factions in the depths of the universe.

12. The 100

Screenshot from the TV show The 100

(Image credit: Warner Bros. Television)
  • Released: March 19, 2014
  • Seasons: 7
  • Cast: Eliza Taylor, Bob Morley, Marie Avgeropoulos

Picture this. The Earth becomes inhabitable following a nuclear conflict. You’re one of 100 juvenile delinquents living on a failing space station, hoping for a return to the planet and starting again. What could possibly go wrong?

Well, in the post-apocalyptic drama The 100 seemingly there’s a lot that can happen. For seven seasons, this teen-centric show warps into a deeper, darker tale of conflict, power struggles, and heartbreaking decisions. Based loosely on the book series of the same name by Kass Morgan, viewers watch as the 100 teens travel to Earth and embark on a battle of ownership between them and the adults already living there. Whilst it was originally coined as a teen drama, it has more to offer to audiences of all ages.

11.  Stargate SG-1

Screenshot from TV show Stargate SG-1

(Image credit: Double Secret Productions)
  • Released: July 27, 1997
  • Seasons: 10
  • Cast: Richard Dean Anderson, Michael Shanks, Amanda Tapping, Christopher Judge

Spanning a decade on our screens, Stargate SG-1 spawned from the 1994 movie, Stargate, and became one of the longest-running sci-fi TV shows of its time. 

Military crew SG-1 assemble to explore a network of Stargates leading to other planets across the solar system. With interstellar space travel a huge part of this show, it should come as no surprise that there’s plenty of alien threats, spaceship battles, and the formation of important alliances across the galaxy. 

Brad Wright and Jonathan Glassner co-created the show after working together on the 90s The Outer Limits remake and ran for an impressive 10 seasons. Several spin-offs were born in its wake, but none quite as successful as Stargate SG-1.

10. Futurama

Futurama_20th Century Fox Television

(Image credit: 20th Century Fox Television)
  • Released: March 28, 1999
  • Seasons: 10
  • Cast: Billy West, Katey Sagal, John DiMaggio, Tress MacNeille

First up, we must pay heed to a cartoon that took the sci-fi genre and ran it deep into humor, calamity, the bizarre, and the brilliant. Futurama comes from the creator of The Simpsons, Matt Groening, and it took sci-fi concepts such as impending doom, the multiverse, time travel, and Leela’s pet and uses them to fantastic comic effect. 

There are fantastic characters like Bender the loud-mouth robot, Professor Farnsworth the forgetful mad scientist, and our favorite, Lord Nibbler, an alien who poops out balls of dark matter. It’s whimsical sci-fi with deeper meaning, but in palatable 20+ minute episodes, making it a great animated sci-fi addition to our list.

9. Quantum Leap

Quantum Leap_Belisarius Productions

(Image credit: Belisarius Productions)
  • Released: March 26, 1989
  • Seasons: 5
  • Cast: Scott Bakula, Dean Stockwell, Deborah Pratt

Quantum Leap, like many of the other entries on our best sci-fi TV shows list, was way ahead of its time. After an experiment goes awry, Dr. Sam Beckett, played by Scott Bakula, gets stuck in a seemingly endless loop of time jumps, taking control of the bodies of various hosts. He quickly realizes that the only way to trigger the next jump is to fix the various mistakes that these people were on track to make in their lives.

While the sci-fi premise is great, what made Quantum Leap so fantastic was its focus on human stories, teaching us that it's never too late to right the course of our lives. The leaping through time concept also meant that the action never stayed in one place long enough for the audience to get bored, as Sam continually leapt through time and space, hoping the next leap would be the leap home. 

8. The Expanse

The Expanse_Alcon Entertainment

(Image credit: Alcon Entertainment)
  • Released: November 23, 2015
  • Seasons: 6
  • Cast: Steven Strait, Dominique Tipper, Wes Chatham, Shohreh Aghdashloo

The Expanse is a show that has been given many lives. Inspired by a series of novels of the same name by James S. A. Corey (hence it’s nabbed a spot on our best sci-fi TV shows based on books list), The Expanse has been passed between TV networks before ending up on Amazon Prime. While it may have faced cancellation, it always found a new home and there’s a reason for that - The Expanse is a TV series that takes sci-fi very seriously. 

Set in a future world where humanity lives across the solar system, there’s a lot to explore and showrunner Naren Shankar leads the way with this gritty sci-fi epic. It doesn’t hurt that he’s got a doctorate in applied physics and electrical engineering either, which helps firmly put the science in science fiction. 

7. The Mandalorian

The Mandalorian_Lucasfilm and Walt Disney Studios

(Image credit: Lucasfilm and Walt Disney Studios)
  • Released: November 12, 2019
  • Seasons: Season 3 out 2022
  • Cast: Pedro Pascal, Carl Weathers, Barry Lowin, Giancarlo Esposito

The Mandalorian is our most modern entry on the list, but it takes the baton of a franchise that has been at the forefront of all things sci-fi for many, many years. Easily one of the best sci-fi tv shows out there at the moment, The Mandalorian tells the story of a lone bounty hunter who has been tasked with retrieving ‘The Child.’ 

With an epic storyline and the introduction of the instantly iconic Baby Yoda, this Disney Plus original takes viewers on whirlwind adventures across the galaxy following the fall of the Empire. With a host of famed directors behind it, The Mandalorian is the shining star of the Star Wars franchise. 

6. Doctor Who

Doctor Who_BBC

(Image credit: BBC)
  • Released: November 23, 1963
  • Seasons: 26 (ongoing)
  • Cast: William Hartnell, Tom Baker, David Tennant, Jodie Whittaker

Doctor Who is the sci-fi TV show that keeps on giving. Hailing from the U.K., Doctor Who is the longest running sci-fi series in TV history, with 26 seasons and 869 episodes and counting (there was a rather large hiatus between 1989 and 2005 though).

If you don’t know already, Doctor Who follows the Doctor, a time-traveling alien who pilots the TARDIS, a spaceship disguised as an old fashioned police box. The Doctor has a unique ability to regenerate instead of dying, which is a fun in-universe explanation for changing actors for the titular role. Check out our list of the Doctor Who Doctors, ranked to see which have been our favorites over the years.

There’s time travel, there’s science, and there’s a joyful humor to it that has kept fans interested in the Doctor’s adventures for decades which is why it cements itself as one of the best sci-fi TV shows of all time. 

5. Stranger Things

Stranger Things_Netflix

(Image credit: Netflix)
  • Released: July 15, 2016
  • Seasons: 4 (ongoing)
  • Cast: Millie Bobby Brown, Finn Wolfhard, Winona Ryder

Next, we head to the upside down in 1980s Indiana for Stranger Things, an incredibly popular sci-fi original from Netflix. Following a group of young friends, this series tackles the theme of growing up in a time where nothing is quite as it seems. If you're all about that 80s vibe, then Stranger Things will be right up your alley.

Supernatural occurrences, secret government cover-ups, and experimental tests are all hidden within the rural town of Hawkins. A great cast underscored with some great music makes for a fun, and at times scary, sci-fi spectacular.

4. The Twilight Zone

The Twilight Zone_Cayuga Productions

(Image credit: Cayuga Productions)
  • Released: October 2, 1959
  • Seasons: 5
  • Cast: Rod Serling, Robert McCord, Jay Overholts

You have now crossed over into… The Twilight Zone, the incredible brainchild and passion project of TV host, Rod Serling. After many years in politics, he took a huge left turn into sci-fi, creating an anthology series spanning over 150 episodes and five years. Frequently brushing up against the spooky and paranormal as often as traditional sci-fi, The Twilight Zone often left viewers pondering their own humanity after every unique episode. 

Never mind trying to sleep after ‘Living Doll’ or ‘Mirror Image.’ Reborn in 2019 by screenwriter Jordan Peele, the man behind Us and Get Out, The Twilight Zone has found its place both back then and now.

3. The X Files

The X Files_20th Century Fox Television

(Image credit: 20th Century Fox Television)
  • Released: September 10, 1993
  • Seasons: 11
  • Cast: David Duchovny, Gillian Anderson, Mitch Pileggi

Mulder and Scully are two standout names in the sci-fi genre and they’re the beloved duo of this iconic sci-fi TV series, The X Files. The two FBI agents lead the series, played famously by David Duchovny and Gillian Anderson, taking on unexplainable cases of paranormal activity. 

In some instances, they’re so shocking that an episode was even banned from being aired on TV. Bouncing between monster of the week style episodes and a grand, overarching conspiracy storyline, The X Files tackled everything from Bigfoot and the Chupacabra to the Roswell Aliens and murderous AI systems. 

With creative stories, an excellent cast, and an other-worldly theme tune, we're here to tell you that the truth is out there, and it’s that The X Files is one of the best sci-fi TV shows of all time.

2. Battlestar Galactica

Battlestar Galactica_BSkyB

(Image credit: BSkyB)
  • Released: October 18, 2004
  • Seasons: 4
  • Cast: Edward James Olmos, Mary McDonnell, Jamie Bamber

Running for five years and four seasons, 2004’s Battlestar Galactica is a reboot of the famed sci-fi franchise created by Glen A. Larson. Of all the reimaginations of the franchise, this Battlestar Galactica series was the longest-running and most successful, winning numerous awards for its epic journey through space toward the last-remaining colony that is Earth. 

A plot that navigates its way through the emotions of being the last surviving members of the human race, and the stress and strains it brings alongside it. Full of character depth, intense battles, intrigue, love stories, and an epic soundtrack to boot - Battlestar Galactica was nearly unmatched.

1. Star Trek: The Next Generation

Star Trek The Next Generation_Paramount Television

(Image credit: Paramount Television)
  • Released: September 26, 1987
  • Seasons: 7
  • Cast: Patrick Stewart, Brent Spiner, Jonathan Frakes

You may be wondering why Star Trek: The Next Generation has earned a spot on our best sci-fi TV series list and the original has not. Well, arguably, in all honesty, because it's better (we've already talked about this in our Kirk vs Picard article). We don’t think creator Gene Roddenberry would be mad about that though, considering he wrote both of them. 

Almost two decades after the original, with an animated series in-between, Patrick Stewart takes on the role of Captain Jean-Luc Picard of the U.S.S. Enterprise-D to go where no one has gone before. The crew go on a spectacular exploration across time and space that ultimately led to much, much more for the Star Trek franchise, that’s still thriving today. 

It's a phenomenal sci-fi saga spanning seven seasons that takes a more measured, civilized approach to space exploration, allowing us to ponder what it means to be human in between epic space battles. A fantastic premise, cast, and execution sees Star Trek: The Next Generation win our crown for the best sci-fi TV show of all time.

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