Star Trek has featured a plethora of intriguing villain species over its seven-decade run, as well as a few that haven't quite worked. As humans sought out new life and new civilizations in Star Trek's future, they were bound to run into some that weren't exactly friendly. The antagonistic species the crew of the USS Enterprise and other Starfleet vessels encountered were often reflections of humanity's own past failings, with fascist regimes and violent dictatorships in full swing across the galaxy.
Not every Star Trek story features a cut-and-dry alien villain; sometimes Starfleet officers face aliens with whom they simply have a misunderstanding in good faith, like Captain Jean-Luc Picard (Patrick Stewart) and an unintelligible Tamarian captain in the classic Star Trek: The Next Generation episode "Darmok," or the misunderstood creature called the Horta encountered by Captain James T. Kirk (William Shatner) in the Star Trek: The Original Series episode "The Devil In The Dark." That said, most of Star Trek's iconic antagonists are alien species with clear hostility toward the idealism Starfleet and the Federation stand for. Here's a ranking of every major Star Trek villain species.
