Thomas Ambrose Gaunt (1829 – 5 June 1890) was a jeweller, clockmaker, and manufacturer of scientific instruments, whose head office and showroom were at 337–339 Bourke Street, Melbourne, Victoria, Australia.
[3] He gained a reputation for reliability: each morning he set the main chronometer at the Bourke Street premises by telegraph signal from the Melbourne Observatory.
Scientific instruments produced by the company included kymographs, thermographs, thermohygrographs and the like, as well as mercury-in-glass barometers and thermometers.
They also manufactured gold and silver devotional jewellery and ecclesiastical ornaments, notably for St Patrick's Cathedral.
Two became nuns at the Abbotsford Convent and one daughter, Cecelia Mary Gaunt (died 28 July 1941), married William Stanilaus Spillane on 22 September 1886 and had a large family.