Burns was baptised at Mauchline, Ayrshire, Scotland in April 1796, the son of estate manager Gilbert Burns, who was the brother of the poet Robert Burns. In 1826, he was ordained as minister of the parish of Ballantrae, and in 1830 married Clementina Grant, the daughter of an episcopal minister in Edinburgh.
In his childhood Thomas attended Haddington Grammar School and then the University of Edinburgh, where he studied theology.
The proposal for a Free Church settlement in New Zealand gained Burns"s interest, and he was offered the position of minister of the New Edinburgh scheme (later the Otago scheme) in June 1843. Burns and William Cargill established a lay association to promote the settlement in May 1845. They arrived at the new settlement of Dunedin on 15 April 1848.
A firm and devout churchman, he also possessed farming skills from his childhood upbringing, and as such, he was a strict but practical man in the early days of the new settlement.
He presided over the setting up of the Synod of Otago and Southland in 1866, and established the presbyteries of Dunedin, Clutha and Southland. A strong supporter of education, he helped establish both Otago Boys" High School and Otago Girls" High School during the 1870s, and was on the founding committee of the University of Otago, of which he was first Chancellor from 1869 until his death on 23 January 1871.
He is buried in Dunedin Southern Cemetery.
