The Acteon Galaxy, or Acteon Group, (PROSE: Tragedy Day) was the galaxy in which Metebelis III was located, (AUDIO: Worldwide Web) and possibly Inter Minor, as the Third Doctor expected to have wound up somewhere else in the galaxy when he learned he overshot Metebelis III. (TV: Carnival of Monsters)
The Agellae were a belligerent race from the Acteon Galaxy that attacked the Hexagora on Zagara IX. (AUDIO: Hexagora)
The Eighth Doctor's TARDIS ended up near the galaxy whilst escaping from the Time Lords' time torpedoes. (AUDIO: Neverland)