The Mega-Federation is the governing body of at least the Milky Way Galaxy, established by the year 12,265. It consists of humans, Vulcans, Romulans, Klingons, Cardassians, and Founders, to name a few. It is a highly technological society which commissions the USS UberEnterprise to explore the universe. Around 750,000 years later, the races of the Mega-Federation evolve beyond physical bodies.

The Mega-Federation is likely descended from the United Federation of Planets. (ST short story: "Our Million-Year Mission")