Thornbury is a small township on the east bank of the lower Aparima River, in western Southland, New Zealand.
Local small industries include machinery and transport/trucking companies, and a tannery.
The township was founded by pioneer settlers Matthew Instone and Robert Foster.
It was named by Robert Foster after his wife's birthplace, the market town of Thornbury, in Gloucestershire, England.
The railway line from Invercargill split at Thornbury, with one branch going around the coast to Riverton and Tuatapere/Orawia, and the Wairio Branch going inland to the coal mines at Nightcaps.