The Reductus Sector is home to Phobian, the Adeptus Astartes Homeworld of the Dark Hunters Chapter. The sector is also the last known location of the Knights of Gryphonne Chapter, who were reduced to a fleet-based organisation after the destruction of their homeworld elsewhere in the segmentum.
- Phobian - Homeworld of the Dark Hunters Chapter.
- Rapture - Knight World, homeworld of House Aramos. Devastated by the tyranids of Hive Fleet Leviathan.
- Stratos - Mining World and Ocean World located in the Hadron Belt.
- 1: Codex: Space Marines (5th Edition), pg. 30
- 2: Codex: Imperial Guard (5th Edition), pg. 26
- 3: Codex: Imperial Knights (6th Edition), pg. 11
- 4: Fires of War (Short Story)