Galactic empires are a fairly common theme in science fiction. Many authors have either used a galaxy-spanning empire as background, or written about the growth or decline of such an empire. The capital of a galactic empire is frequently a core world. Some of these empires are clearly based on the Roman Empire; the Galactic Empire of Isaac Asimov's Foundation series (which inspired empires of later writers and film-makers) being an obvious example. The best known to the general public today is probably the empire from Star Wars, which was formed in turn from the Galactic Republic.

There was also a turn based strategy game called "Galactic Empire" for the Commodore C64, which had nothing to do with any of the science fiction themes mentioned above.

Galactic Empires in Science Fiction

• Dune - Padishah Empire
• Foundation Series - Galactic Empire (Asimov)
• The Hitchhiker's Guide to the Galaxy - Imperatala Galacticon
• Star Wars - Galactic Empire (Star Wars)
• Warhammer 40,000 - Imperium (Warhammer 40,000)
• Legend of the Galactic Heroes - Galactic Empire
• Klingon Empire , Romulan Empire , and Dominion in Star Trek
• Honorverse -- Solarian League, the largest of political units of human diaspora can be considered such an Empire; from the late novels in the series it also becomes aparent, that the League is at the beginning of its fall.

Galactic Empires in Religion

• The Galactic Confederacy in the Church of Scientology.
• The Aetherius Society's "Interplanetary Parliament".
• The "Elohim" in Raëlism.

Galactic Empires in Computer games

• Imperium Galactica Series By Digital Reality.
• Pax Imperia: Eminent Domain by THQ.
• Space Empires Series by Malfador Machinations.
• EVE Online MMORPG by CCP Games.

Fictional governments | Science fiction themes

Imperio Galáctico | Impero galattico | 銀河帝国