The Bajorans (variously pronounced /bəˈdʒɔːrənz/ bə-JOR-ənz, /bæˈdʒɔːrənz/ baj-OR-ənz, /bəˈʒɔːrənz/ bə-ZHOR-ənz) are a fictional species in the science-fiction Star Trek franchise. They are a humanoid extraterrestrial species native to the planet Bajor, who have a long-standing enmity with the Cardassians, owing to decades of subjugation under a military dictatorship which saw many of their species enslaved or forced into exile away from their homeworld. They were first introduced in the 1991 episode "Ensign Ro" of Star Trek: The Next Generation, and subsequently were a pivotal element of Star Trek: Deep Space Nine and also appeared in Star Trek: Voyager and Star Trek: Picard.

The shows' writers initially depicted the Bajorans as an oppressed people who were often forced to live as refugees, whom they likened to a variety of ethnic groups. Rick Berman, who helped to originally conceive them, compared them to "The Kurds, the Palestinians, the Jews in the 1940s, the boat people from Haiti—unfortunately, the homeless and terrorism are problems in every age." Ronald D. Moore similarly commented, "depending on the episode, you could also call Bajor Israel, or Iran, or even America and the Cardassians could be Germans, or Russians or several other examples ... [but] we don't really try to make Bajor a direct analogy to any specific contemporary country or people."

Various Bajoran characters were included in several of the Star Trek series, including Ro Laren (played by Michelle Forbes) in The Next Generation as well as a number of others in Deep Space Nine, which was set on a space station near to Bajor, and which featured Bajoran characters such as Kira Nerys (Nana Visitor) and Winn Adami (Louise Fletcher).

According to the fictional storyline of the Star Trek universe, the Bajorans are an ancient species who developed advanced technology before the evolution of humanity on Earth. They eventually developed space-faring ships, which took them as far away as the planet of Cardassia. In 2318 the Cardassian Union, which had been taken over by a military dictatorship, invaded Bajor, occupying it for fifty years, during which time they forced many Bajorans into slave labor, using them in their various mining operations. This forced many Bajorans to flee and live in refugee camps away from Cardassian domination, while other Bajorans became involved in the resistance movement, organising terrorist attacks against Cardassian targets.

The Federation could not intervene in the situation, due to Prime Directive considerations; since Bajor had formally aligned itself with the Cardassians some time before, it was considered an internal matter between the Cardassian Union and a member/subject planet. This caused some resentment towards the Federation by the Bajoran people, especially when the Federation was initially invited to administer Deep Space Nine. This latent anger led to the formation of the Circle, an anti Non Bajorian movement which almost succeeded in capturing Deep Space Nine-until the "Circle" was exposed as being secretly supported by the Cardassians so that a Bajor without Federation Support would be severely weakened.

In 2369, the Cardassian civilian authorities ordered the military to withdraw from Bajor, after which the Bajoran Provisional Government invited the United Federation of Planets to set up base on the former Cardassian mining station of Terok Nor, renaming it Deep Space Nine, and requesting membership into the Federation.

In 2369, when Commander (later Captain) Benjamin Sisko was assigned command of DS9, one of his instructions was to prepare Bajor for full membership into the Federation (pilot episode: "Emissary"). This was a long-running theme during the rest of the series. In 2373, with the Dominion War on the horizon, Bajor asks to be admitted to the Federation under special circumstances. Sisko, acting as Emissary of the Prophets, warned that if Bajor were to join the Federation at that time, it would mean the destruction of that world. With this warning, Bajor decided not to accept membership at that time. At the start of the Dominion War, Bajor officially declared their neutrality ("Call to Arms"), although many Bajorans joined Starfleet and, as well, a new resistance to the occupation of Deep Space Nine was formed.

Like many aliens on Star Trek, the Bajorans are human-like in appearance, but have a distinctive symmetrical facial feature: a series of horizontal ridges on the bridge of the nose between the eyes. Despite their human-like appearance, there are several biological differences between the two species.