Serpent Nebula
Location:	Nineteen Pillars of Ascension / Milky Way Galaxy Bastion Space/ Milky Way Galaxy Flarunium Realm / Milky Way Galaxy Council space / Milky Way Galaxy Dominion Space / Milky Way Galaxy
System(s):	Widow Boltzmann
Relay(s):	Widow Relay
Population:	8 billion
Species:	Leviathan Tatha Navariao Zeioph Arthenn Zommeo Aebomt Tleiqreobue Stryvet Tlaxxeohst Priwrix Craddapt Faff Stuah'ua Thorians Inusannon Prothean Asari Salarian Turian Human Hanar Drell Elcor Volus Keeper Batarian Quarian Krogan
Affiliation:	Prothean Empire United Citadel Council of Species New United Galactic Front of Races United Galactic Confederacy Galactic Dominion Unified Galactic Republics
Tier:	Tier VIII
Capital:	Citadel (until 2253 CE) Capitol

The Serpent Nebula is a cluster located deep in Council space, and formerly the chosen seat of the Citadel Council. The most consistently occupied cluster in galactic history, the Serpent Nebula was home to the Citadel, the colossal space station used by thousands of societies as the capital of their civilizations. In the asari cycle, the Serpent Nebula was the capital cluster of the Citadel Council and New Council, until it fell to the Galactic Dominion in the Post-Apocalyptic War. Following the formation of the Unified Galactic Republics, it has remained the capital of the Milky Way Galaxy, with the Citadel's replacement, Capitol, being moved to the cluster to serve as the new capital. Since then, the Serpent Nebula has remained a core part of Milky Way governance.

The cluster is named for the shape of the nebula, which is said to look like a snake.