The Empire of Orion, also called the Orionic Empire was a state that existed early in Orion history.
Through the Guardian of Forever on the Time Planet, a research team consisting of Captain James T. Kirk, Commander Spock, and Lieutenant Ted Erickson of Starfleet, and historians Grey and Loom Aleek-Om, visited the dawn of Orion civilization in 2269. (TAS episode: "Yesteryear")
Here, they visited the ancient and barbaric early Empire of Orion. Going in, none of them knew what the casual clothing of the era was, and Starfleet uniform and 23rd century Federation casual dress was expected to be conspicuous. Gold was the only currency.
Kirk expected the trip to be fun and adventurous, and found it to be a whirlwind of colors, sights and sounds, as they explored the period for 2.5 days in local time. Their last visit was to a low-quality inn in a bazaar, near an auction of Orion slave girls. (TAS novelization: Yesteryear)
- The Empire of Orion may be related to the Thakolarivaj, or "Great Orion Empire", of the Last Unicorn/Decipher RPG version of Orion history, or the Orion Empire in the FASA RPG history, or the Second Empire mentioned in ST novel: The Children of Kings.