Murchison is a town in the Tasman Region of the South Island of New Zealand. It is near the western end of the "Four Rivers Plain", at the confluence of the Buller River and the Mātakitaki River. The other two rivers are the Mangles River, and the Matiri River. It is a rural service town for the surrounding mixed farming district, approximately halfway between Westport and Nelson. Murchison was named after the Scottish geologist Roderick Murchison, one of the founders of the Royal Geographical Society.

Tasman District is a local government district in the northwest of the South Island of New Zealand. It borders the Canterbury Region, West Coast Region, Marlborough Region and Nelson City. It is administered by the Tasman District Council, a unitary authority, which sits at Richmond, with community boards serving outlying communities in Motueka and Golden Bay / Mohua. The city of Nelson has its own unitary authority separate from Tasman District, and together they comprise a single region in some contexts, but not for local government functions or resource management (planning) functions.