The Rift Federation is a relatively minor association of planets which has aligned itself with the Alliance in its war against the Syndicate Worlds.
Containing relatively few inhabited planets, the Rift Federation had initially been neutral in the conflict, but was drawn in on the side of the Alliance some time after the Battle of Grendel. The Rift Federation contributed ships to the joint fleet sent to assault the Syndic home system, though the Rift Navy contingent was the smallest of the three making up the force. Following the Syndic massacre of the Alliance flag officers in the Syndic home system, the Rift captains agreed to follow the recommendations of Callas Republic Co-President Victoria Rione.

Following the conclusion of the Alliance-Syndicate War, the Rift Federation began taking steps to distance itself from the Alliance, seeking to reassert its independence. Despite this, the majority of Federation warships were initially ordered to remain under Admiral Geary's command as part of the newly formed Alliance First Fleet. The Federation has since withdrawn from its previous military cooperation agreement with the Alliance.