In 2373, the United Federation of Planets consisted of at least 150 member planets, spread over 8000 lightyears. (Star Trek: First Contact)
- We may assume, that the admission policy of the Federation regards governments and/or planets, and not whole species.
Founding members
The United Federation of Planets was founded in 2161 by the following members:
- Alpha Centauri colony
- Independent Earth colony. (Star Trek: Generations)
- Andoria
- Homeworld of the Andorians and the Andorian Empire. (Star Trek: Generations)
- Earth
- Homeworld of the Humans and United Earth. (Star Trek: Generations)
- Tellar
- Homeworld of the Tellarites (Star Trek: Generations)
- Vulcan
- Homeworld of the Vulcans and the Vulcan High Command. (Star Trek: Generations)
Council members
The following are members of the Federation who have known to be on the Federation Council.
- Althos IV
- Homeworld of the Bzzit Khaht. (Star Trek IV: The Voyage Home)
- Arcadia
- Homeworld of the Arcadians. (Star Trek IV: The Voyage Home)
- Cait
- Homeworld of the Caitians. (Star Trek IV: The Voyage Home)
- Delta IV
- Homeworld of the Deltans. (Star Trek IV: The Voyage Home)
- Efros
- Homeworld of the Efrosians. (Star Trek VI: The Undiscovered Country)
- Fillandia
- Homeworld of the Ariolo. (Star Trek IV: The Voyage Home)
- Grazer
- Homeworld of the Grazerites. (DS9: "Homefront")
- Kashet
- Homeworld of the Kasheeta. (Star Trek IV: The Voyage Home)
- Medusan Homeworld
- Homeworld of the Medusans. (TOS: "Is There in Truth No Beauty?")
- Rhaandaran
- Homeworld of the Rhaandarites. (Star Trek IV: The Voyage Home)
- Xelata
- Homeworld of the Xelatians. (Star Trek IV: The Voyage Home)
- Zaran II
- Homeworld of the Zaranites. (Star Trek IV: The Voyage Home)
Other Known members
The following are members of the Federation who may or may not have Council privileges.
- Aaamazzara
- Homeworld of the Aaamazzarites. (Star Trek: The Motion Picture)
- Arken II
- Homeworld of the Arkenites. (Star Trek IV: The Voyage Home)
- Aurelia
- Homeworld of the Aurelians. (TAS: "Yesteryear")
- Betazed
- Homeworld of the Betazoids. (TNG: "Haven")
- Arcturus IV
- Homeworld of the Arcturians. (Star Trek: The Motion Picture)
- Ardana
- Homeworld of the Ardanans. (TOS: "The Cloud Minders")
- Betelgeuse II
- Homeworld of the Betelgeusians. (Star Trek: The Motion Picture)
- Coridan
- Homeworld of the Coridans. (TNG: "Sarek")
- K'norm
- Homeworld of the K'normians. (Star Trek: The Motion Picture)
- Kazar
- Homeworld of the Kazarites. (Star Trek: The Motion Picture)
- Kobheerian Homeworld
- Homeworld of the Kobheerians. (DS9: "Second Skin")
- O'Ryan's Planet
- Homeworld of the Shamin. (Star Trek: The Motion Picture)
- Peliar Zel
- Homeworld of the Peliar Zel natives. (TNG: "The Host")
- Rigellian Homeworld
- Homeworld of the Rigellians. (Star Trek: The Motion Picture)
- Risa
- Homeworld of the Risans. (TNG: "Captain's Holiday")
- Sauria
- Homeworld of the Saurians. (Star Trek: The Motion Picture)
- Zakdorn Homeworld
- Homeworld of the Zakdorn. (TNG: "Peak Performance")
Protectorates
- Evora Homeworld
- Homeworld of the Evora. (Star Trek: Insurrection)
Probable Members
The following homeworlds have had members in Starfleet. Barring a special admittance from a high-ranking Starfleet Captain or Admiral, they were most likely citizens.
- Argosian Homeworld
- Homeworld of the Argosians. (DS9: "Dax")
- Benzar
- Homeworld of the Benzites. (TNG: "Coming of Age")
- Bolarus IX
- Homeworld of the Bolians. (TNG: "Allegiance")
- Elaysia
- Homeworld of the Elaysians. (DS9: "Melora")
- Halii
- Homeworld of the Haliians. (TNG: "Aquiel")
- Ktaris
- Homeworld of the Ktarians. (VOY: "The Voyager Conspiracy")
- Napean Homeworld
- Homeworld of the Napeans. (TNG: "Eye of the Beholder")
- Tiburon
- Homeworld of the Tiburonians. (DS9: "The Ship")
- Trill
- Homeworld of the Trill. (DS9: "Emissary")
- Zaldan Homeworld
- Homeworld of the Zaldans. (TNG: "Coming of Age")
The planets and moons of the Sol system besides Earth, aswell as extrasolar Earth colonies, such as Vega colony and Terra Nova colony are most likely Federation members or at least Federation protectorates, too.
Coalition of Planets
Many members of the Coalition of Planets later joined the Federation. In addition to the Coalition members known to have joined the Federation, these members might have joined as well.
- Denobula Triaxa
- Homeworld of the Denobulans. (ENT: "Demons")
- Rigel V
- Homeworld of the Rigelians. (ENT: "Demons")
Proposed members
These following are in the process of gaining Federation member status.
- Angosia III (2366)
- Homeworld of the Angosians. (TNG: "The Hunted")
- Antede III (2365)
- Homeworld of the Antedeans. (TNG: "Manhunt")
- Antica (2364)
- Homeworld of the Anticans. (TNG: "Lonely Among Us")
- Bajor (2377)
- Homeworld of the Bajorans. (DS9: "Emissary")
- Cairn Homeworld (2370)
- Homeworld of the Cairn. (TNG: "Dark Page")
- Catulla (2269)
- Homeworld of the Catullans. (TOS: "The Way to Eden")
- Gideon (2268)
- Homeworld of the Gideon natives and the Gideon Council. (TOS: "The Mark of Gideon")
- Kesprytt III (2370)
- Homeworld of the Kesprytt and the Kes and Prytt governments. (TNG: "Attached")
- Selay (2364)
- Homeworld of the Selay. (TNG: "Lonely Among Us")
Star Chart
In a 2364 Federation star chart, the following planets were bordered and given special signifigance. (TNG: "Conspiracy")
- Whether or not these are Federation members, Federation Colonies/Planets, Surrounded by the Federation, or simply heavily explored areas is unknown.
- Aldebaran III
- Possibly the Aldebaran colony. (TOS: "The Deadly Years")
- Alfa 177
- Note that in 2266, this planet was uninhabited, and doesn't seem viable for a colony. (TOS: "The Enemy Within")
- Alpha Majoris I
- Homeworld to the Mellitus and a native population. (TOS: "Wolf in the Fold")
- Altair VI
- Has a native population and government. (TOS: "Amok Time")
- Arret
- It is unknown if Arret has a population, but if it is a Federation member, then it probably does. (TOS: "Return to Tomorrow")
- Ariannus
- It is unknown if this is a Federation colony, or if it has its own native population. (TOS: "Let That Be Your Last Battlefield")
- Babel
- Note that in TOS: "Journey to Babel," this was stated to be in neutral space.
- Benecia
- Home of the Benecia colony. (TOS: "The Conscience of the King")
- Berengaria VII
- Probably uninhabited, contains a dragon-like species. (TOS: "This Side of Paradise")
- Beta Aurigae system
- An unknown planet in the inhabited Beta Aurigae star system. (TOS: "Turnabout Intruder")
- Beta Lyrae system
- An unknown planet in the Beta Lyrae star system. (TAS: "The Slaver Weapon")
- Beta Niobe system
- Note that Beta Niobe went nova in 2269, leading one to wonder about how a Federation membership is possible in 2364. (TOS: "All Our Yesterdays")
- Beta Portolan system
- The planets in this system were decimated long ago, but it may be populated by a colony. (TOS: "Operation -- Annihilate!")
- Camus II
- Note that it was uninhabited in TOS: "Turnabout Intruder."
- Canopus system
- Alpha Carinae is mentioned and there are various inhabited planets in its star system, including:
- Alpha Carinae II : Has a native population. (TOS: "The Ultimate Computer")
- Canopus III : Possibly has a native population, known for a dinosaur species. (TAS: "Eye of the Beholder")
- Note that this is seen later on the chart, so it is separate from the other "Alpha Carinae" member.
- Alpha Carinae V : Homeworld of the Drella and a native population. (TOS: "Wolf in the Fold")
- Canopus Planet : Probably has a native population, home of poet Phineas Tarbolde. (TOS: "Where No Man Has Gone Before")
- Capella IV
- Homeworld of the Capellans and the Ten Tribes. (TOS: "Friday's Child")
- Since the planet was pre-industrial, the chart may have been referencing another planet in the Capella system.
- Daran V
- An inhabited planet. (TOS: "For the World is Hollow and I Have Touched the Sky")
- Deneb system
- An inhabited planet in the Deneb system of which there are four.
- Deneb II : Contains a native population. (TOS: "Wolf in the Fold")
- Deneb IV : Homeworld of the Bandi and another telepathic species. (TOS: "Where No Man Has Gone Before")
- Deneb V : Homeworld of the Denebians. (TOS: "I, Mudd")
- Alpha Cygnus IX : Possibly inhabited. (TNG: "Sarek")
- Delta Vega
- An uninhabited planet and Federation outpost. (TOS: "Where No Man Has Gone Before")
- Eminiar system
- An inhabited planet in the Eminiar system, of which there are two. (TOS: "A Taste of Armageddon")
- Vendikar : Independent Colony of the Eminiar VII.
- Eminiar VII : Homeworld of the Eminians and the Eminian Union.
- Fabrina
- Homeworld of the Fabrini. (TOS: "For the World is Hollow and I Have Touched the Sky")
- Note that the original Fabrina was destroyed, so this may be a reference to there colonized home.
- First Federation Homeworld
- Homeworld of the First Federation. (TOS: "The Corbomite Maneuver")
- Gamma Canaris IV
- Possibly a colony world. (TOS: "Metamorphosis")
- Gamma Trianguli VI
- Home of the Gamma Trianguli VI natives. (TOS: "The Apple")
- They don't seem technologically advanced enough to join the Federation, so they might be a protectorate or perhaps there is a more advanced culture elsewhere in the Gamma Trianguli system.
- Holberg 917G
- An uninhabited planet in the Omega system. (TOS: "Requiem for Methuselah")
- Note unless an independent colony was established, it is unknown how this could be a Federation member.
- Ingraham B
- Possibly a colony. (TOS: "Operation -- Annihilate!")
- Janus VI
- Homeworld of the Horta and the Janus VI colony. (TOS: "The Devil in the Dark")
- Early plans for Star Trek IV: The Voyage Home were to include Horta in the Federation Council scenes.
- Kling
- A planet believed to be in the Klingon Empire. (TNG: "Heart of Glory")
- It is very doubtful that a Klingon planet would join the Federation, as this information would be contradicted in later episodes.
- Kzin
- Homeworld of the Kzinti and the Kzin Patriarchy. (TAS: "The Slaver Weapon")
- Lactra VII
- Homeworld of the Lactrans. (TAS: "Eye of the Beholder")
- Makus III
- Probably contains a native population and government. (TOS: "The Galileo Seven")
- Marcos XII
- Possibly a Federation colony. (TOS: "And the Children Shall Lead")
- Memory Alpha
- An uninhabited planetoid containing the largest Federation library. (TOS: "The Lights of Zetar")
- Mudd
- Inhabited by androids. (TOS: "I, Mudd")
- Omega Cygni system
- An inhabited planet in this system.
- Omega IV
- Homeworld of the Omega IV natives, and specifically the Kohms and Yangs. (TOS: "The Omega Glory")
- Organia
- Supposed Homeworld of the Organians and the Organian Council of Elders. (TOS: "Errand of Mercy")
- While it is unlikely that the Organians are members of the Federation themselves, a colony might have started on the planet following the Treaty of Organia.
- Orion
- Homeworld of the Orions, and former homeworld of the Orion Syndicate. (TOS: "[The Cage]]")
- Note that chart may be referencing the friendlier Orion I.
- Phylos
- Homeworld of the Phylosians. (TAS: "The Infinite Vulcan")
- Psi 2000
- An uninhabited planet that disintegrated in 2266. (TOS: "The Naked Time")
- Note that it is unclear why this would be on a Federation chart 98 years later, but perhaps this is referring to the Psi 2000's star system, and an inhabited world existed nearby.
- Pollux IV
- An uninhabited planet. (TOS: "Who Mourns for Adonais?")
- It is unknown if a colony was built on this planet.
- Pollux system
- Other than Pollux IV, its star Beta Geminorum was also mentioned, leading one to think that another inhabited world exists in the system.
- Pyris VII
- An uninhabited planet. (TOS: "Catspaw")
- It is unknown why this planet would rise to prominence on the chart.
- Regulan system
- An inhabited planet in the Regulus star system, of which there are two.
- Regulus III : Has a population. (DS9: "Fascination")
- Regulus V: Class M, possibly has a population. (TOS: "Amok Time")
- Sarpeid system
- An inhabited planet in the Sarpeid star system.
- Sirius IX
- Homeworld to a native population and a planetary government. (TAS: "The Slaver Weapon")
- Talos IV
- Homeworld of the Talosians. (TOS: "The Cage")
- Note that the Talos IV was considered off limits in 2267. The chart simply mentioned "Talos," so there may be another population in the system.
- Tau Ceti system
- An inhabited planet in the Tau Ceti star system of which there are three:
- Tau Ceti Prime : Possibly a colony or resort planet. (VOY: "Coda")
- Tau Ceti III : Possibly a colony, but may be inhabited. (TNG: "Conspiracy")
- Tau Ceti IV : Home of the ship port Amber. (Star Trek II: The Wrath of Khan)
- Theta III
- Nothing is known of this planet.
- Tholian Assembly Homeworld
- Homeworld of the Tholians and the Tholian Assembly. (TOS: "The Tholian Web")
- Later references in TNG made the Tholians' inclusion in the Federation unlikely.
Future Members
The following are depicted as Federation members in a possible future timeline. (ENT: "Azati Prime")
- Ithenite Homeworld
- Homeworld of the Ithenites.
- Qo'noS
- Homeworld of the Klingons and the Klingon Empire (See also: Klingon planets)
- Xindi Homeworld
- Homeworld of the Xindi.