The vast universe of Star Trek is home to an array of heroes and villains. Whether or not their intent is malicious or mischievous, villains always stand in opposition to the heroes, preventing them from achieving their goal. It helps that the writers of the show are some skilled artists in their own right to give the audience these compelling characters. Not all villains on this list have malicious intent but every single one is powerful and deadly. Here are some of the most dangerous foes to ever oppose the brave captains, crew and other allies in Star Trek.
Although he's not necessarily malevolent, there's no way a bored, almost omnipotent being isn't dangerous. Q has a low opinion of human beings generally, but he's fascinated by Captain Picard of Star Trek: The Next Generation. Every so often he shows up, of course completely by surprise, to play another savage head game with the Enterprise and her crew. He's a rogue member of the Q Continuum, a society of aliens with similar godlike powers. Throughout TNG and other shows that are part of the Star Trek universe, he appears on several ships, in various costumes, and takes the crew on numerous wacky adventures. Sometimes things get real with Q and move beyond the realm of dangerous mischief, like the trial against Humanity and the Q Civil War, which put whole races and galaxies in danger.
9 Charlie X
Sometimes the most terrifying enemy is the most vulnerable and least threatening, so you never see it coming. When the crew of Star Trek: The Original Series (TOS) agrees to transport a lanky teenage boy from a science vessel to his surviving family on a nearby human colony, they have no warning about his true nature. Stranded for years by a gruesome crash, Charlie survived on his own from toddlerhood, learning to speak from the computers. However, those computers couldn't teach Charlie about human behavior, and when he is frustrated by a rebuke or rejection, his immense power begins to manifest. It starts with small things, like making Uhura lose her voice, and escalates to terrifying levels, such as causing the science vessel he came from to explode.
Just when Charlie's rampage reaches a dizzying crescendo, making crew members and weapons disappear into thin air, we get our twist ending and find out that Charlie didn't grow up alone after all. He could also be one of the most sympathetic villains in the entire canon. His final words, "I wanna stay" echo sadly on the bridge after he fades away.
8 Khan Noonien Singh
Probably the most recognizable of all the villains or even main characters throughout the Star Trek universe, Khan was put in opposition to Kirk when he first appeared in Star Trek TOS: Space Seed. His history on earth as a genetically-engineered despotic tyrant wasn't a good start. Khan was always aggressive and demanding and could back up his plans with a keen intellect and brute force. His initial defeat ended in a compromise. For all we knew, he was safe and happy where Kirk had left him on Ceti Alpha V. Their parting wasn't exactly amicable but it was certainly not hostile initially. When we learn the cold truth of what became of the would-be colony in the film Star Trek: Wrath of Khan, however, we can't help but sympathize with him when he vows to take revenge on Kirk for being exiled on a doomed planet. The fact that Kirk didn't know that is a moot point, and a good thing too, otherwise this epic battle and its array of related internet memes would not exist.
The crew of the Enterprise encounter what looks like a cloud moving towards earth. Hidden within is what seems like an alien ship. It's already destroyed several Klingon ships by the time it reaches them and actually possesses the body of a crew member, not only to learn and communicate but also to use them to achieve its goal. Like other dangerous villains, it is eventually appeased rather than destroyed.
Tony Stark said, "We create our own demons." And that's V'Ger in a nutshell. Star Trek: The Motion Picture doesn't have a lot going for it unless you're into the visuals. Just get the Enterprise on the big screen, worry about the story, casting and characters later. On the other hand, this movie has some compelling stories to tell, like the one of V'Ger. An early form of artificial intelligence, V'Ger is an adversary who doesn't understand the concepts of good and evil, let alone something as abstract as empathy.
6 Dr. Tolain Soran
He started out as a brilliant, driven scientist. Then he went to Heaven and got kicked out. And then he went stark raving mad. Compare his expression of grief to that of Piccard, who also loses family members in the movie Star Trek: Generations. Soran first appears as a reasonable person. We soon find out he is so obsessed with returning to that mysterious entity called The Nexus that it consumes him and anyone else around him. He even goes so far to destroy an entire planet, and this is where our heroic captains appear.
Picard and Kirk must work together to stop Soran and escape The Nexus. The tragedy that follows is what really puts Soran on this list, as by the end of the film he's accomplished that countless other bad guys could never do. He succeeds in killing Captain Kirk.
5 The Borg Queen
It's been theorized that the mysterious, sentient entity V'Ger was the genesis of the Borg. They definitely share the same ruthless drive to learn, control, and most of all, assimilate. The Borg is a terrifying entity, to begin with, and the Borg Queen is a step above the hive mind she controls. She seems to possess some knowledge of human emotions, making her a brutal adversary once she's in your head. Data and Captain Picard find this out the hard way, and it's only Data's loyalty and intelligence that save them in the end. What makes the Queen so dangerous is that she's almost impossible to kill. Her consciousness is always preserved within the Borg, and despite Captain Janeway's efforts to destroy the Borg Queen completely, she might still be out there.
4 The Duras Sisters
You can't help but admire this dynamic duo. Members of the Klingon House of Duras, Lursa and B'Etor were responsible for starting the Civil War that divided the Klingon Empire. Even though their younger brother, the male and therefore the heir, was officially the one in charge it was the sisters who really ruled. They were allied with the Romulans, notorious enemies of the Federation, and Soran, the mad scientist who was responsible for the death of Captain Kirk. In Star Trek: Generations they take Geordi La Forge hostage after Soran kidnaps him. Always being resourceful and never missing an opportunity, they implant a bug in his VISOR so they can use him as an unwitting spy when they return him to his ship. The ensuing battle results in their deaths, but the Enterprise is so badly damaged it crashes on a nearby planet.
Data could be one of the most valuable members of the Enterprise crew. What would happen if he was an enemy instead of an ally? A virtual copy of Data, this android might have come from the mirror universe, as he's basically Data's evil twin. While Data is inquisitive, helpful and essentially good, Lore is jealous, deceptive and manipulative.
He contacted the Crystalline Entity to destroy the colony where he was created. He also offered the Entity the crew of the Enterprise-D in TNG: Datalore. Lore killed his own creator and even allied with the Borg to try and infiltrate the federation. He was deactivated permanently in TNG: Descent, Part II. His last words sound heartfelt but we don't know how honest he is.
2 Professor James Moriarty
We're not sure who thought the holodeck was a good idea. It seems the Federation didn't vet this properly, because it gives the crew of TNG no end of trouble. Of course, Moriarty was always a fictional character, but the person who gave the great mind of Sherlock Holmes a hard time would be a formidable opponent. He appears in two episodes with connected storylines, Elementary, My Dear Data in season 2 and Ship in a Bottle in season 6. Geordi La Forge unwittingly creates this entity when he asks the Holodeck to create someone that would be an intellectual match for Data. The result is a virtual Moriarty. In his quest to escape the confines of virtual reality and live as an independent being, he takes control of the ship's computers until he is talked down by Picard.
A Klingon to make all Klingons proud, Kruge often goes overlooked as a villain since he only appears in Star Trek III, The Search for Spock. He does even more damage than Khan in the previous film and seems just as ruthless. He's so driven and savage that he kills his own wife to ensure the details of their secret mission, to discover the secret of the Genesis Project, remain hidden. He does seem to hesitate for a split second in this regard, but in the true Klingon fashion he pulls the trigger and she's proud to die with honor. He keeps a vicious Targ hound by his Captain's chair, a reflection of his own brutal nature. The trial of destruction he leaves in his wake is impressive. He not only succeeds in seriously compromising the secrets of Genesis, but he murders Kirk's son David and causes the destruction of the original starship Enterprise.