The Twelve Galaxies was a regional or political group of galaxies.
Planets in the Twelve Galaxies included Proamon, Svartos, (TV: Dragonfire) Feles, (PROSE: Invasion of the Cat-People) Albar, and Desolation. The Rally of the Twelve Galaxies took place on 94 planets in the region. (TV: The Ghost Monument)
Irving Braxiatel wrote legislation to prohibit the use of Time Scoops throughout the Twelve Galaxies. (AUDIO: Panacea) Currencies used in the Twelve Galaxies included krin, kavlons, forvalars, and trynties. (TV: The Ghost Monument)
Contestants in the Rally of the Twelve Galaxies included Albarians and Muxterans. (TV: The Ghost Monument) The Cat-People were spread across the Twelve Galaxies when, during an energy crisis, they were called back to the litter-world Feles. (PROSE: Invasion of the Cat-People) The Stenza terrorised the planets Albar and Desolation. (TV: The Ghost Monument)
In the year 4590, the F19 Mk9 Starfighter was considered one of the most efficient and deadly starfighters ever built, "capable of outmanoeuvring and destroying every battle weapon in the Twelve Galaxies." (PROSE: Resurrection of the Daleks)
Around the year 2,000,000, Kane tried convincing Ace to join him by saying that the Twelve Galaxies could be hers. The Seventh Doctor later offered to take her on a trip around the Twelve Galaxies before taking her home to Perivale. (TV: Dragonfire)