The Horatian system (also known as the Horatius sun system) was a star system that was beyond the borders of the United Federation of Planets, having been settled by Humans wishing to avoid Federation contact. It contained three Class M planets. This system was a part of NGC 434.

The system was discovered by accident during the early days of interstellar travel, when a freighter in warp drive accidentally entered underspace. When the ship was forced back into warp, it materialized near Horatius and landed on one of the Class M planets to perform repairs before returning to the Federation. The system was ignored by the Federation due to its great distance. (TOS novel: Mission to Horatius)

• Horatius (primary)
  • Neolithia
  • Mythra
  • Bavarya