Star Citizen is set in the 30th century in a galaxy dominated by the United Empire of Earth, a human government that grew out of earlier polities — the United Nations of Earth and then the United Planets of Earth. Humanity's expansion accelerated after the discovery of jump points, naturally occurring wormholes that link star systems and make practical interstellar travel possible. The UEE is governed by an Imperator and a Senate, and draws a sharp distinction between citizens (typically earned through service) and civilians. The current era follows the fall of the Messer dynasty and a long, ongoing reform movement reshaping the empire's relationship with its frontier worlds and alien neighbours.

Beyond the UEE, several established civilizations and a constant churn of smaller powers share the galaxy.

• UEE. The dominant human state, organised around a militarised civil service and a citizen / civilian divide.
• Banu. A merchant species organised as the Banu Protectorate — a loose confederation of trading worlds. First contact with humanity occurred in the 25th century and established trade, not war, as a viable template.
• Xi'an. A long-lived, methodical species governing the Xi'an Empire. Relations with humanity were hostile for centuries before normalising into a cautious peace.
• Vanduul. A nomadic, clan-based species in chronic conflict with the UEE along the frontier, particularly around lost human systems.
• Tevarin. A proud warrior culture twice defeated by humanity in the Tevarin Wars; survivors live mostly within UEE space.

A handful of star systems carry outsized weight in everyday life and current events.

• Sol. Humanity's home system and the symbolic heart of the empire, with Earth as its political and cultural centre.
• Terra. A prosperous, Earth-like world that has grown into a political and commercial rival to Sol, often associated with reformist sentiment.
• Stanton. A fully corporate-owned system whose four planets belong to major megacorporations — the setting most players first encounter.
• Pyro. A lawless, unclaimed system adjacent to Stanton, dominated by outlaw groups and contested resource sites.
• Nyx, Cathcart, and other border systems. Frontier and unclaimed space where smugglers, prospectors, and independents operate beyond steady UEE reach.

A short list of turning points that shape the present day.

• Discovery of jump points. Nick Croshaw's transit through the first known jump point opened practical interstellar travel and triggered humanity's expansion beyond Sol.
• First contact with the Banu. Humanity's first meeting with another spacefaring civilization, establishing trade rather than war as a possible template.
• Tevarin Wars. Two conflicts in which the UNE / UPE defeated the Tevarin, ending their independent civilization and absorbing survivors into human space.
• The Messer Era. A long period of authoritarian rule under the Messer dynasty, marked by militarism, censorship, and aggressive expansion before its eventual collapse and reform.
• Loss of systems to the Vanduul. Sustained Vanduul raids and incursions led to the loss of frontier human worlds and remain a defining security concern.