31 Days of Horror: The 5 Scariest Star Trek Episodes

Horror isn’t just a genre; it’s an amalgamation of pop culture, cozy traditions, and things that go bump in the night. This year, we're taking our 31 Days of Horror across the entire cultural spectrum. We’ll be taking a look at movies that scare us, games that kept us paranoid, scary books we cozy up with under blankets, music that sets that spooky tone and seasonal food we’re craving–or strange food you’d have to tie us up and force feed us. Whether you’re looking for something truly terrifying or a cozy autumn haunt, come back every day this month for a new bite-sized review or spooky adjacent list.

Star Trek isn’t necessarily known for being scary, but there are a few episodes that are genuinely creepy. I mean, the first aired episode of Star Trek was  “The Man Trap” which was a creature feature about a salt vampire that can appear as different people while stalking and killing Enterprise crew members. The Original Series even had an overt horror episode in “Catspaw” which featured a gothic mansion, a giant cat, and ghosts–with Kirk using his masculine wiles to get the upper hand, of course.

But I wanted to figure out what the scariest Star Trek episodes were. And I’m not talking about “Sub Rosa” and its sexually charged ghost–a ghost that went on to play Shakaar in Deep Space Nine, by the way. 

These are the 5 scariest Star Trek episodes.

5: “All Those who Wander” Strange New Worlds. 

While Voyager attempted an Aliens-like story with “Macrocosm,” it was miles behind “All Those Who Wander.” Trapped on a frozen disabled ship the crew of the Enterprise have to survive mutating Gorn hatchlings in a visceral survival thriller. Its high production values help drive home the scares–and how terrifying the Gorn can be. It’s also an episode that taught us that not all of the Enterprise crew and/or cast regulars are safe.

4. “Empok Nor” Deep Space Nine

I don’t always like the trope where a character is forced to do bad things because of mind control or some other mind altering reason, but despite that being a main plot point for “Empok Nor” there are a few reasons it works here. For one: the person affected is (alleged) Cardassian Spy Garak, who uses all of his knowledge he acquired in the Obsidian Order to play a deadly cat and mouse game with Miles O’Brien and the other Starfleet offiders. It shows Andrew Robinson’s range, and how scary he can be as the “simple tailor” Garak.

3. “Schisms” The Next Generation

This is an episode that lives in my head, rent free. This episode leans heavily into the alien abduction vibes. Several crew members have a shared, traumatic memory that they have to piece together to discover the disturbing truth. There are a few freaky moments in episodes of The Next Generation, but none are quite as unsettling as “Schisms.” Its most famous scene has affected crew members trying to recreate their memory using the holodeck, blindly recreating a cold, clicking alien surgical theater based on their shared subconscious trauma. 

2. “Impulse” Enterprise 

“Impulse” is probably remembered for being Star Trek’s take on the zombie genre, and that’s why it’s on this list. The Enterprise crew board a drifting Vulcan ship only to discover the entire crew has been driven into a state of rabid, violent psychosis. Seeing hordes of normally stoic, logical Vulcans reduced to screaming monsters is genuinely scary. 

1. “The Thaw” Voyager. When lists of scariest Star Trek episodes come up, “The Thaw” is usually on it. And for good reason. THe crew of the USS Voyager come across a planet where there are a few colonists in hibernation, but their minds are kept active by a program. It turns out the program has warped into a living nightmare, with “The Clown”--an embodiment of fear played brilliantly by Michael McKean has to match wits against a mostly helpless Voyager crew trying to free their crewmates now trapped in the nightmare. It’s a terrifying premise  with an incredibly satisfying (but terrifying in its own way) ending. 

Star Trek may be built on a foundation of optimism and scientific exploration, but as these episodes prove, the franchise isn't afraid to turn off the lights and lean into pure terror when the story demands it. Whether it's psychological thrillers, haunted space stations, or visceral survival horror, Trek handles the genre surprisingly well. But with over 900 episodes across the franchise, there are bound to be some creepy moments left off this list. Did I miss a genuinely terrifying episode? Does the clicking from "Schisms" still keep you up at night? Let me know your pick for the scariest Star Trek episode in the comments below.