Thomas Baldwin (c.1750 – 7 March 1820) was an English surveyor and architect in the city of Bath.
He did not originally hail from Bath but was first recorded in the city in 1774, where he was initially a clerk (later builder and assistant) to plumber, glazier, and politician Thomas Warr Attwood. By 1775, he was appointed as the Bath City Architect after Attwood's death. During the construction of the Guildhall during 1775, he was officially appointed the position of Bath City Surveyor. He was surveyor to the Pulteney Estate and planned the development of Bathwick as well as being responsible for much of the building. Around the same time he was appointed to the Office of Architect and Surveyor for the Improvement Commissioners (formed by the Bath Improvement Act of 1789) on 9 April 1790 (at a salary of 200 pounds per annum), which he held until 1793.
Baldwin married Elizabeth Chapman in St James' Church, Bath on 15 September 1779, which is ironic because it was designed by John Palmer of Bath between 1768–1769, the man who would investigate and destroy Baldwin's reputation, and then steal his commissions and positions. The Chapmans were a local political family, and a month after his marriage he was appointed Deputy Chamberlain to the Corporation of Bath. He was again appointed to this post on 7 January 1782, and again on 6 October 1783. His salary for this post, as recorded in October 1790 was 210 pounds per annum. He began to quarrel with the Corporation and was dismissed from this post in October 1791.
Rival architect John Palmer began investigating Baldwin and at the same time stole commissions from him, including the enlargement scheme (adding an attic story) of the General Hospital. After Baldwin submitted his records to the Improvement Commissioners, Palmer was then appointed to investigate the work carried out on the Pump Room on 14 December 1792. Palmer naturally found issues and ordered work there stopped. By 17 May 1793, a committee was formed by the Improvement Commissioners to investigate Baldwin and he was dismissed (on 28 June 1793). This was followed by being dismissed from his other positions in 1793 for financial irregularities, although he was able to maintain the Pulteney office. A creditor named Edmunds commenced bankruptcy procedures against him on 15 August 1793 and he was finally declared so on 26 August 1802, which allowed him to re-launch his career after that.