Thomas Grubb (4 August 1800 – 19 September 1878) was an Irish optician and founder of the Grubb Telescope Company.
Thomas started out in 1830 in Dublin as a metal billiard-table manufacturer. He diversified into making telescopes and erected a public observatory near his factory at 1 Upper Charlemont Street, Portobello, Dublin. As makers of some of the largest and best-known telescopes of the Victorian era, the company was at the forefront of optical and mechanical engineering. His innovations for large telescopes included clock-driven polar mounts, whiffletree mirror mounting cells and Cassegrain reflector optics.
Grubb helped build the famous telescope for William Parsons, 3rd Earl of Rosse, at Birr, County Offaly, Ireland. One of his earliest instruments - the telescope for Markree Observatory in County Sligo in the West of Ireland, supplied in 1834 - was, for several years, the largest telescope in the world. It was used to sketch Halley's comet in 1835 and to view the solar eclipse of 15 May 1836.
He died in 1878 and is buried at Mount Jerome Cemetery, Dublin, Ireland. He had married Sarah Palmer. Their youngest son was Sir Howard Grubb, who took over the optical business. Thomas Grubb's cousin, John Grubb Richardson (1813 - 1891) was a major Irish industrialist who founded the model village of Bessbrook.
- Glass, I.S. (1997). Victorian Telescope Makers: The Lives and Letters of Thomas and Howard Grubb. Institute of Physics Publishing (Taylor and Francis). ISBN 0-7503-0454-5.
- A Short History of Armagh Observatory
- History of the Cauchoix objective
- Todd, David Peck; Lynn, William Thynne (1899). Stars and Telescopes. Boston: Little, Brown, and Company.
- Grubb, Geoffrey Watkins (1972). The Grubbs of Tipperary. Mercer Press.