Erewhon may refer to:
- the Erewhon System.
- the planet Erewhon, the sole inhabited planet in the system.
- the Republic of Erewhon, the local star nation.
- the Erewhon Navy, the Republic's spaceborn military.
- the Erewhon Army, the Republic's ground forces.
- the Erewhon Wormhole Junction, a wormhole in the system.
- the Erewhon Terminus, the local terminus of the wormhole.