Factions are major powers in Star Trek Online. While many factions are encountered in PVE missions, only two factions are currently playable. The United Federation of Planets faction is available to all players at the start of the game. The Klingon Empire faction is only unlocked once players have attained a Federation character with a rank equal to or greater than level 20.
The May 2013 update Legacy of Romulus will allow players to create characters belonging to the Romulan Republic faction at level 1, and bring Klingon characters to parity by also being available at level 1.
 United Federation of Planets
 Klingon Empire Sub-Factions
 Romulan Republic
The Romulan Republic will become available to players in the Legacy of Romulus update of 21st May 2013.