10 Most Terrifying Sci-Fi Movies of All Time 

The sci-fi genre has long been one of the most consistently popular and inventive in modern fiction. Its very definition requires looking into the future, examining humanity and its progress as the world around us and the fabric of our society evolves, often with technological advancement at its heart. Science fiction has fascinated audiences for many years, with modern blockbusters further broadening the genre’s scope to deliver thought-provoking stories. However, there’s another side to many common sci-fi tropes that sees the genre often feature moments of horror, where the march of progress is often imagined to have overtaken mankind’s ability to control the world around us.

There are many great sci-fi movies, but making a truly terrifying piece of sci-fi horror is something else entirely. As well as delivering plausible and well-presented science fiction, these movies must also capture the terrifying essence of their central themes in order to appropriately frighten their audience. It’s a delicate balance to strike, and one that requires careful consideration, but when executed well, it makes for some of the most terrifying movies out there.

1) Annihilation (2018)

Directed by Alex Garland and loosely based on the novel of the same name by Jeff VanderMeer, 2018’s Annihilation is often hailed as one of the best sci-fi movies of the 2010s. It follows a team of scientists who enter a quarantine zone named the Shimmer, which is populated by mutated plant and animal life caused by an extraterrestrial presence. With a star-studded cast featuring Natalie Portman, Tessa Thompson, Jennifer Jason Leigh, Gina Rodriguez, Tuva Novotny, and Oscar Isaac, Annihilation captured the imagination of many.

What makes it such a terrifying movie isn’t jump scares or a frightening villain, but a simple dedication to depicting the sheer horror that an alien presence could visit upon humanity. The Shimmer is a place where reality becomes increasingly warped, altering those who step inside drastically and in horrifying ways. It’s a calculated and mind-bending story that makes great use of purely existential horror, making Annihilation a deeply unnerving watch from beginning to end.

2) Possessor (2020)

Written and directed by Brandon Cronenberg—son of David Cronenberg, the master of body horror—2020’s Possessor is a frightening and underrated piece of sci-fi horror. Starring Andrea Riseborough as Taysa Vos, an assassin who transfers her consciousness into unwitting host bodies in order to perform hits, Possessor‘s story concerns Vos’ difficulty in controlling her latest host body in a fight for control with its original owner. Also starring Rossif Sutherland, Tuppence Middleton, Sean Bean, and Jennifer Jason Leigh, Possessor boasts an impressive range of talent both on and off the screen.

A deeply unnerving movie, Possessor delivers a masterclass in sci-fi horror. Described by critics as an unsettling psychological thriller, it taps into key elements of both sci-fi and horror to deliver a film that examines deeper themes in a way that both engages and terrifies on multiple levels. It’s a tense and provocative film that pushes boundaries while also making timely examinations about modern society, making Possessor an incredibly frightening and interesting movie.

3) Predator (1987)

The very beginning of the Predator movie franchise started incredibly strong, spawning one of the most beloved sci-fi horror series in modern cinema. 1987’s Predator features an elite team of paramilitary operators tasked with saving hostages from guerrillas in a Central American rainforest, only to discover it has become the hunting ground of a powerful alien presence. The movie has gone on to earn a place in sci-fi history, with its gleefully violent action a terrifying introduction to one of the genre’s most frightening villains.

What makes Predator so scary is that it is a surprisingly nuanced movie. On the surface, it’s a relatively simple piece of sci-fi horror about overconfident humans facing an enemy much stronger and more advanced than themselves. However, it’s also a cutting examination of the machismo of the action genre, subverting numerous tropes by making its action heroes fodder for a largely unseen foe. There’s a very good reason that the franchise it spawned remains so popular, and that’s because of the exceptionally scary foundations laid by the first movie.

4) Under the Skin (2013)

2013’s Under the Skin features Scarlett Johansson in one of her most memorable sci-fi roles to date. The movie follows a character identified as the Female (Johansson), an extraterrestrial disguised as a woman who preys on men. However, what makes it such a terrifying movie isn’t necessarily its story, but rather the atmosphere of dark introspection that it creates.

Under the Skin‘s depiction of a predatory alien living on Earth and carving out her own survival at the cost of others’ lives is standard sci-fi fare in many ways. However, the unnerving and inhuman performance of Scarlett Johansson is a key part of Under the Skin‘s ability to send chills down the spine of its audience; even while she commits horrific acts, the movie conjures an element of empathy for her character. Her own fate is every bit as horrifying as her victims, lending the movie even more of an air of the deeply uncomfortable and intimately frightening.

5) Invasion of the Body Snatchers (1978)

1978’s Invasion of the Body Snatchers is one of the best-known sci-fi horror movies of all time, not just for its quality but for its wider impact on pop culture. The movie, based on Jack Finney’s 1955 novel The Body Snatchers, follows a pair of San Francisco health inspectors who discover that humans are being secretly replaced by alien duplicates devoid of any humanity or empathy. It’s also known for delivering one of the most perfect sci-fi movie endings of all time.

It’s the nature of Invasion of the Body Snatchers‘ villains that make the movie so terrifying. The notion that a person could be replaced by a perfect biological duplicate makes for a distinct air of paranoia that cannot be denied, with the movie taking this idea and using it to build towards a deeply unsettling climax. It’s a movie that remains terrifying even decades after release through the simple merit of its sci-fi story, and one that has truly left its mark on the genre for all to see.

6) Event Horizon (1997)

While Event Horizon isn’t considered a sci-fi classic, its status as something of a spiritual successor to 1979’s Alien has helped cement its cult reputation. Its story concerns the titular ship, long considered lost in space, found seemingly derelict in orbit of Neptune, and the rescue mission that ensues. The presence of an extradimensional entity on board is the driving force behind the movie’s plot, and proves to be appropriately horrifying as to make Event Horizon an especially memorable cinematic outing.

The level of gruesome visual horror on display is either sheer brilliance or stomach-churning, depending on who you ask. There’s a wider, existential level to Event Horizon‘s story that brings a whole new layer of horror to the movie, with humanity’s own place in the universe seeming insignificant thanks to the terrifying perspective it offers. Though audiences continue to share mixed opinions on the movie, it’s nonetheless a frightening chapter in the cinematic history of sci-fi.

7) Altered States (1980)

Unlike many other movies in the genre, 1980’s Altered States doesn’t rely on sci-fi movie twists or excessive violence to make its story memorable. It follows a psychopathologist researching sensory deprivation, who, over a decade of obsessive experimentation, reaches a terrifying breakthrough. While it may have become relatively obscure in comparison to some of its contemporaries, Altered States remains a flawless piece of horrifying sci-fi.

While it doesn’t feature extraterrestrial or robotic villains, Altered States boasts something arguably more terrifying. Its story explores the dangers of unlocking the darker parts of human consciousness, and its delivery of this idea using both psychological and body horror is truly exceptional. Altered States is a deeply unsettling, memorably terrifying, and sadly underrated piece of sci-fi that deserves to be mentioned alongside all of the genre’s most frightening entries.

8) The Thing (1982)

John Carpenter’s The Thing is one of the best-loved sci-fi movies of the 1980s. Its story follows a team of American researchers on an Antarctic base who encounter a malevolent and deceptive extraterrestrial being. After inadvertently allowing it into their base, it begins consuming and duplicating the scientists, prompting the survivors to grow increasingly distrustful of one another. Starring Kurt Russell, Keith David, A. Wilford Brimley, and T.K. Carter as part of a large ensemble, The Thing remains a sci-fi horror classic.

What makes The Thing such a terrifying movie is the way it blends its sci-fi premise with visual and psychological horror throughout. While the titular alien being is capable of perfectly mimicking other lifeforms, its transformations make for grotesque body horror, while other scenes highlight the futility of being isolated and distrustful of everyone around. In many ways, The Thing is a bleak movie that outlines just how hopeless a struggle against a more powerful and advanced being can be.

9) The Fly (1986)

While David Cronenberg can boast being responsible for multiple instances of iconic body horror, few are as impressive as 1986’s The Fly. The movie stars Jeff Goldblum as eccentric scientist Seth Brundle who develops revolutionary teleportation technology, only to inadvertently fuse his own DNA with that of a housefly while using it. The movie chronicles Brundle’s transformation from a brilliant scientist to a grotesque, insectoid villain.

The Fly is commonly considered one of the greatest examples of body horror in sci-fi cinema. David Cronenberg’s mastery of the subgenre is plain to see, as The Fly is deeply disturbing on multiple levels. Its visual presentation of Brundle’s transformation, as well as the thematic implications of its story, combine to make The Fly one of the most terrifying and profoundly unnerving movies in the history of the sci-fi genre.

10) Alien (1979)

Ridley Scott’s Alien is commonly considered one of the best sci-fi movies ever made, and its legacy certainly lends credence to the notion. Following the crew of the mining spacecraft, the Nostromo, Alien sees the vessel unwittingly transporting an extraterrestrial being known as the Xenomorph. What follows is a space-set slaughter at the hands of the Xenomorph—one of the best sci-fi movie villains ever—ending with just a single survivor in the form of Sigourney Weaver’s Ripley.

There’s a reason that Alien remains one of the most horrifying sci-fi movies ever made. The movie’s deep-seated claustrophobia, which stems from its setting on an enclosed ship, makes the threat of the Xenomorph all the more pressing, and the movie’s use of darkness and visual misdirection only increases the tension. Alien is a rare example of a movie that blends a perfect balance of sci-fi and horror, fitting squarely into both genres as one of the most brilliant and terrifying movies of all time.