The Oceania Union is a union in the Cosmic Era encompassing the geographic region of Oceania, which includes the Australian continent and its neighboring nations. The capital is located in Wellington, New Zealand. The Oceania Union aims to improves its global competitiveness as well as its gross domestic product by actively accepting Coordinators as part of the labor workforce. During the First Alliance-PLANT War, it allied itself with the PLANTs, and hosted the Carpentaria Base, ZAFT's first terrestrial stronghold.
|Factions of the Cosmic Era|
|Atlantic Federation | Eurasian Federation | Republic of East Asia | South Africa Union | United States of South America | OMNI Enforcer | Blue Cosmos/Logos | Phantom Pain|
|PLANT Supreme Council | ZAFT | African Community | Oceania Union|
|Equatorial Union | Kingdom of Scandinavia | Orb Union | Three Ships Alliance/Clyne Faction | Terminal | DSSD | Mars Colony|
|Actaeon Industries | Adukurf Mechano-Industries | Fujiyama Company | Junk Guild | Serpent Tail | Morgenroete | Librarian Works|