Federation members
The membership of the United Federation of Planets consisted of worlds and species with shared principles of universal liberty, rights and equality. ()

At its founding in 2161, the Federation began with four members: Earth, Andoria,  and Tellar Prime. ()

By 2373, the Federation consisted of at least one hundred and fifty member planets, spread over eight thousand light years. ()

At its peak, the Federation included 350 member worlds. By 3189, as a result of The Burn, there were only 38 known to Federation Headquarters. ()

After the cause of The Burn was discovered, the Emerald Chain crippled, and a planet made of Dilithium was discovered, the Federation began to rebuild with worlds such as  and Ni'Var rejoining the Federation, leading to membership numbering at 60 in 3190. () After the  made contact with Species 10-C, additional worlds opened negotiations to join or rejoin. Such as Andoria who began talks and Earth who were ready to rejoin immediately. ()

Federation planets

Founding members

The United Federation of Planets was founded in 2161 by the following members:
Andoria  Homeworld of the Andorians and the Andorian Empire. () By 3190, they had left, but talks to rejoin commenced after the DMA crisis. ()
Earth  Homeworld of the Humans and United Earth; left the Federation following the Burn in 3089. (; ) Voiced intent to rejoin in 3190. ()
Tellar Prime  Homeworld of the Tellarites. () They were the only founding member that never left into the 32nd century. ()
  Homeworld of the Vulcans and the Vulcan High Command. Planet renamed to Ni'Var following Vulcan-Romulan reunification; left the Federation following the Burn in 3089, and rejoined in 3190. (; ; )

Council members 

The following are members of the Federation who are known to be on the Federation Council.
Arcadian homeworld  Homeworld of the Arcadians. ()
Ariolo homeworld  Homeworld of the Ariolo. ()
Bzzit Khaht homeworld  Homeworld of the Bzzit Khaht. ()
Caitian homeworld  Homeworld of the Caitians. ()
Delta IV  Homeworld of the Deltans. ()
Grazerite homeworld  Homeworld of the Grazerites. ()
Kasheeta homeworld  Homeworld of the Kasheeta. ()
Unnamed Federation planet  Home to the unnamed alien council members. ()

Xelatian homeworld  Homeworld of the Xelatians. ()
Zaranite homeworld  Homeworld of the Zaranites. (; ; )

Other known members 
Algolian homeworld  Homeworld of the Algolians. ()

Arbazan homeworld  Homeworld of the Arbazan. ()

Ardana  Homeworld of the Ardanans. ()
Barzan II  Homeworld of the Barzan. ()
Benzar  Homeworld of the Benzites. ()
Betazed  Homeworld of the Betazoids. ()
Bolarus IX  Homeworld of the Bolians. (; )

Coridan  Homeworld of the Coridanites. ()
Efrosian homeworld  Homeworld of the Efrosians. ()

Gelrak V  Homeworld of the Gelrakians. ()
Haliian homeworld  Homeworld of the Haliians. ()
Hekaras II  Homeworld of the Hekarans. ()
Kaminar  Homeworld of the Kelpiens and the Ba'ul. ()
Peliar Zel II  Homeworld of the Pelians. ()
Rigel IV  Homeworld of the Rigellians. ()
Risa  Homeworld of the Risians. ()
  Homeworld of the Trill. ()
Unnamed Federation planet  Home to the unnamed alien ambassadors. ()
Unnamed Federation planet  Home to the unnamed copper-skinned aliens. ()

Unnamed Federation planet  Home to the unnamed cross-dressing delegates. ()
Unnamed Federation planet  Home to the unnamed female delegates. ()
Unnamed Federation planet  Home to Volis' species. ()
Unnamed Federation planet  Home to the unnamed brown-skinned delegates. ()
Zakdorn homeworld  Homeworld of the Zakdorn. ()
Zelonite homeworld  Homeworld of the Zelonites. ()

Furthermore, Ithenite, Klingons, and Xindi were mentioned by  as part of the Federation in a possible 26th century. ()

Protectorates 

Evora homeworld  Homeworld of the Evora. ()

Coppelius (also called Ghulion IV) Homeworld of the Coppelius androids. ()

Colonies

Proposed members 

These following were in the process of gaining Federation member status as of the year indicated.
Angosia III (2366) Homeworld of the Angosians. ()
Antede III (2365) Homeworld of the Antedians. ()
Antica (2364) Homeworld of the Anticans. ()
Bajor (2373) Homeworld of the Bajorans. ()
Cairn homeworld (2370) Homeworld of the Cairn. ()
Catulla (2269) Homeworld of the Catullans. ()
 (2268) Homeworld of the Gideon and the Gideon Council. ()
Kesprytt III (2370) Homeworld of the Kesprytt and the  and Prytt governments. ()
 (2364) Homeworld of the Selay. ()

Uninhabitable 
 Galorndon Core

Appendices

Related topics 
 Federation colonies
 Species with representatives in Starfleet
 Coalition of Planets

Background information
In , set in 2268, the ambassadors of Federation planets attended the Babel Conference, at that time there were thirty-two ambassadors, suggesting there were at least thirty-two member worlds in the Federation at that time. 

According to a dossier on the home page of , in the alternate reality, the Federation had one hundred twenty member planets and seven hundred colonies in the 2250s. 

According to Star Trek: Star Charts (United Federation of Planets IV), in 2378, there were 183 members and 7,128 affiliates. The area of the Federation was eight thousand cubic light years. At the last census, in 2370, there were 985 billion individuals living in the Federation.

Aleek-Om was identified as a "Federation historian" in the Star Trek Concordance, possibly based on the script, suggesting  might be a member. Bilana III was also identified as a member in the  and Star Trek: Star Charts. In Star Trek Onlines Agents of Yesterday expansion pack, Mizar IV was the site of a Federation colony, suggesting that Mizar II is located within Federation space and holds a membership on the Federation Council.

 introduced the idea of "Federation aligned species", though no examples were given. According to , by 2399 thousands of species depended on the Federation for unity and cohesion.

External links

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fr:Membres de la Fédération
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