The Galactic Union is an interplanetary governing body active in the 28th century.
- The Union was formed on the foundation of the Khitomer Alliance between the United Federation of Planets, Klingon Empire, and Romulan Republic.
- In 2769, representatives of the members of the Union gathered at New Khitomer to ratify the Temporal Accords.
- “Time and Tide”: The player travels to 2769 to witness the signing of the Temporal Accords.
- According to Benjamin Walker, there are timelines in which the alliance between the Federation, Klingons, and Romulans failed, and the Galactic Union was never formed.
- It is unclear which species are members of the Galactic Union. Representatives of the Federation (now including the Romulans), Dominion, Deferi, Breen, Tholians, Xindi, Cardassians, Orions, Lukari, Ferengi, Cooperative, and Kobali are all present to witness the signing of the Temporal Accords; whether they are all members of the Union is unconfirmed.
- There is no Klingon Empire representative present at the signing of the Temporal Accords; however, the Federation Ambassador is a Klingon, suggesting that the Empire, like the Romulans, may have joined the Federation by 2769.