- For other meanings of "Alliance", see Alliance (disambiguation).
An alliance is a treaty or agreement formed between two or more parties for mutual benefit.
- Alliance (28th century), an anti-Federation alliance created in the 28th century. (Star Trek: 001)
- Colonial Alliance, a government in the Pendragon universe formed by planets in the Demilitarized Zone. (Star Trek: Pendragon)
- Federation Alliance, a military and exploratory alliance formed between the Federation as well as a number of other Alpha and Beta quadrant powers.
- Ferengi Alliance, the official name of the Ferengi government.
- Fragma Alliance, an alliance of disparate vessels from the Alpha and Beta Quadrants. (Star Trek: Phoenix-X)
- Klingon-Cardassian Alliance, an alliance in the mirror universe between the Klingons and Cardassians.
- Star Alliance, an alliance of the major powers in the Alpha and Beta Quadrants formed in the 25th century. (Adventures of STAG)
- Steranmio Alliance, was an interstellar entity located some-7,000 light years from the Federation. (Star Trek: The Cantabrian Expeditions)