Thomas Brunner (baptised 22 August 1821, in Oxford, England; died 22 April 1874 in Nelson, New Zealand) was an English-born surveyor and explorer remembered for his exploration of the western coastal areas of New Zealand's South Island.

In 1836, aged fifteen, Brunner was sent to learn surveying from an Oxford architect and surveyor, Thomas Greenshields. Five years later, in 1841, he was appointed by the New Zealand Company as an apprentice surveyor and joined a party of colonists travelling to establish a settlement at Nelson, New Zealand. They arrived at Port Nicholson, New Zealand, on 9 September and then crossed the Cook Strait to the new site, arriving on 4 November.

For two years thereafter, Brunner assisted in the laying out of the new settlement. During that time, the colony began to appropriate more and more of the nearby Wairau plain, but after the Wairau Affray in 1843, the settlement was forced to look south for more farming land. Brunner, working with Kehu, a Māori he had befriended, was one of those exploring the area. In February 1846, he, Kehu, Charles Heaphy and William Fox explored the upper reaches of the Buller River as far as the Maruia River, before dwindling provisions forced their return. Three weeks later, the party, less Fox, left Nelson on a five-month expedition tracing the western coast of South Island as far south as Hokitika. During this time, Brunner and Heaphy became the first Europeans to visit the Poutini Ngāi Tahu settlements at Taramakau, Arahura and Mawhera (now Greymouth). They also identified Aoraki/Mount Cook as New Zealand's highest mountain.