There is a lot of opportunity to succeed, expand, and delight viewers with multiple seasons, recurring cast members, and dedicated writers when a sci-fi idea is brought to life on TV. TV shows can be canceled before they have a chance to shine. That doesn't mean they aren't deserving of a spot on our list. As a TV show, earning cult status is just as good.

The beauty of a TV show that spans multiple episodes is that there is hours upon hours to come up with new ideas. There are so many possibilities with the sci-fi genre. When strange, wonderful, and wacky ideas are pitched to the right people, viewers will get a chance to experience alternate realities from the minds of geniuses.

Our list of the best sci-fi TV shows of all time spans decades, explores galaxy, 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.

Even though the best sci-fi movies get a feature-length slot on the big screen, sci-fi TV shows must captivate the viewer for hours at a time. There's something for everyone in our list. If you want to see more sci-fi greatness, you can check out our best space movies and best space horror movies.

RECOMMENDED VIDEOS FOR YOU...

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 lasted for two seasons. It had to step up to the plate because it was broadcasted around the same time as The Twilight Zone.

The anthology series that brought twisted sci-fi tales to TV screens in the 60s is still going strong today. If the original hadn't set the tone, the modern revival wouldn't have had a chance.

William Shatner starred in "Cold Hands, Warm Heart" and "Demon with a Glass Hand", both of which were classic episodes. The Outer Limits tried out almost unthinkable things in order to warp viewers' perception of 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

In the year 2517, a universal civil war has thrown the galaxy into unrest and the crew on the ship are fighting to survive. In a battle to keep fed and in flight, the team must find themselves working across the universe and dealing with internal conflict.

Firefly was canceled because of low ratings. Maybe it wasn't the right time for a sci-fi show in 2002. In 2005, writer/director Joss Whedon continued his tale in a feature-length movie called "Serenity".

The 14 episodes that made it to the small screen are still enjoyed by fans of the original show. You can find all the episodes here.

  • Buy Firefly on Blu-ray at Amazon (opens in new tab)

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

Babylon 5 is set on a five-mile long spaceship floating in neutral territory and is about five years of political unrest, tensions, and wars. It lasted for five years. It's a lot of fives.

Humans and aliens are on a mission to sort through their differences instead of competing. There is a change to the conflict between Earth and other planets.

It depicted a memorable sci-fi saga from beginning to end that encapsulated its motto that Babylon 5 is the best hope for peace. This epic TV show is a slow burn, but one that keeps viewers interested in the possibility of calm in the depths of the universe.

  • Buy Babylon 5 on DVD at Amazon (opens in new tab)

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

Take a picture of this. Following a nuclear conflict, the Earth is no longer safe. You are one of 100 juvenile delinquents living on a failing space station, hoping for a return to the planet and a new life. What could happen?

There are a lot of things that can happen in The 100. This teen-centered show warps into a deeper, darker tale of conflict, power struggles, and heartbreaking decisions. Based on the book series of the same name by Kass Morgan, viewers watch as the 100 teens travel to Earth and begin a battle of ownership between them and the adults already there. It has more to offer to all ages, even though it was originally dubbed a teen drama.

  • Buy The 100 on Blu-ray at Amazon (opens in new tab)

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

One of the longest- running sci-fi TV shows of its time was spawned from the 1994 movie, Stargate.

A military crew is going to explore a network of Stargates. It should come as no surprise that there are a lot of alien threats, spaceship battles, and alliances in this show.

The Outer Limits remake was co-created by Brad Wright and Jonathan Glassner. Several spin-offs were born in the wake of it, but none were as successful as the one that came before.

  • Buy Stargate SG-1 on Blu-ray at Amazon (opens in new tab)

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

A cartoon that took the sci-fi genre and ran it deep into humor, calamity, the bizarre, and the brilliant, must be paid attention to first. Matt Groening is the creator of The Simpsons and he used sci-fi concepts such as impending doom, the multiverse, and time travel to create a great comic effect.

Lord Nibbler, an alien who poops out balls of dark matter, is one of the great characters. It is a great addition to our list because it is an animated sci-fi that is easy to watch.

  • Buy Futurama on Blu-ray at Amazon (opens in new tab)

9. Quantum Leap

Quantum Leap_Belisarius Productions

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

Many of the other entries on our best sci-fi TV shows list were ahead of their time. Scott Bakula plays Dr. Sam Beckett, who gets stuck in a loop of time jumps after an experiment goes awry. He realized that the only way to get to the next jump was to fix the mistakes these people had made.

The sci-fi premise is great, but it was the focus on human stories that made Quantum Leap so great. The jumping through time concept meant that the action never stayed in one place long enough for the audience to get bored, as Sam constantly leapt through time and space, hoping the next leap would be the leap home.

  • Buy Quantum Leap on Blu-ray at Amazon (opens in new tab)

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

Many lives have been given to The Expanse. The Expanse was passed between TV networks before ending up on Amazon Prime. The Expanse is a TV series that takes sci-fi very seriously and has found a new home despite facing cancellation.

This sci-fi epic is set in a future world where humanity lives across the solar system and ishelmed by Naren Shankar. He has a PhD in applied physics and electrical engineering, which helps put the science in science fiction.

  • Buy The Expanse on Blu-ray at Amazon (opens in new tab)

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 the most modern entry on the list, but it is the franchise that has been at the forefront of all things sci-fi for a long time. One of the best sci-fi tv shows out there at the moment is The Mandalorian, which tells the story of a lone bounty hunter who has been tasked with retrieving the child.

Following the fall of the Empire in this Disney Plus original, viewers are taken on a series of adventures across the universe. The Mandalorian is the star of the Star Wars franchise and is the brainchild of a number of renowned directors.

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 a popular TV show. The longest running sci-fi series in TV history is Doctor Who, which has been on the air for 26 seasons and 869 episodes.

Doctor Who follows the Doctor, a time-traveling alien who pilots a spaceship that looks like a police box. A fun explanation for changing actors for the title role is that the Doctor has a unique ability to regenerate. To find out which Doctor Who Doctors are our favorites, check out our list.

It cements itself as one of the best sci-fi TV shows of all time due to the fact that there is time travel, science, and a joyful humor to it that keeps fans interested in the Doctor's adventures for decades.

  • Buy Doctor Who on Blu-ray at Amazon (opens in new tab)

5. Stranger Things

Stranger Things_Netflix

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

In the 1980's Indiana, we go to see the popular sci-fi series, "Stranger Things". The theme of growing up in a time where nothing is quite as it seems is tackled in this series. If you're a fan of the 80s, then you'll love the show.

Supernatural occurrences, secret government cover-ups, and experimental tests are all found in the rural town of Hawkins. A great cast with great music makes for a great sci-fi movie.

  • Buy Stranger Things on Blu-ray at Amazon (opens in new tab)

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

The brainchild and passion project of TV host, Rod Serling. He created an anthology series that spanned over 150 episodes and five years. The vampire show left viewers pondering their own humanity after every unique episode.

Trying to sleep after a movie is never a good idea. Jordan Peele, who wrote Us and Get Out, is the man behind the new version of The Twilight Zone.

  • Buy The Twilight Zone on Blu-ray at Amazon (opens in new tab)

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

The X Files has two of the best names in sci-fi and they are the beloved duo of the show. The two FBI agents lead the series and take on cases of unexplained phenomena.

They are so shocking that some episodes were banned from being aired on TV. Bouncing between monster of the week style episodes and a grand conspiracy storyline, The X Files tackled everything from Bigfoot to the Aliens.

The truth is out there and The X Files is one of the best sci-fi TV shows of all time.

  • Buy The X Files on Blu-ray at Amazon (opens in new tab)

2. Battlestar Galactica

Battlestar Galactica_BSkyB

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

The original sci-fi series was created by Glen A. Larson and ran for five years. The longest-running and most successful of all the reimaginations of the franchise was the Battlestar Galactica series, which won numerous awards for its epic journey through space towards the last remaining colony on Earth.

A plot that navigates its way through the emotions of being the last surviving member of the human race and the stress and strains that come with it. The show was full of character depth, intense battles, intrigue, love stories, and an epic soundtrack.

  • Buy Battlestar Galactica on Blu-ray at Amazon (opens in new tab)

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 might be wondering why the original Star Trek isn't on our best sci-fi TV series list. It's better because we talked about it in our Kirk vs Picard article. Gene Roddenberry wrote both of them, so we don't think he'd be upset about that.

Patrick Stewart takes on the role of Captain Jean-Luc Picard in an animated series that is almost two decades after the original. The crew went on a spectacular exploration across time and space that eventually led to much, much more for the Star Trek franchise.

It's a fantastic sci-fi saga that takes a more civilized approach to space exploration, allowing us to ponder what it means to be human in between space battles. Star Trek: The Next Generation is the best sci-fi TV show of all time.

  • Buy Star Trek: The Next Generation on Blu-ray at Amazon (opens in new tab)