John Purser
Portrait by his cousin Sarah Purser
Born	(1835-08-24)24 August 1835 Dublin, Ireland
Died	18 October 1903(1903-10-18) (aged 68) Dublin, Ireland
Alma mater	Trinity College, Dublin
Scientific career
Fields	Mathematics
Institutions	Queen's College, Belfast
Notable students	Joseph Larmor, John Henry MacFarland, William McFadden Orr

John Purser (1835–1903) was an Irish mathematician, who was professor at Queen's College, Belfast.

Son of John Tertius Purser (1809–1893), the general manager of the well known brewery Guinness,^[1] Purser was educated in a wealthy family, which included artists, as his cousin Sarah Purser, or engineers, as his brother-in-law John Purser Griffith. He was the brother of mathematician Frederick Purser. He studied in Trinity College, Dublin, graduating BA in mathematics in 1856.

The following years Purser was tutor to the children of Lord Rosse, Lawrence and Charles. In 1863, he was appointed professor of mathematics at Queen's College, Belfast, he was in place until his retirement in 1901.^[2]

Purser is much better known as a teacher than as a researcher,^[3] and he had a good number of notable students, including Sir Joseph Larmor, theoretical physicist who served as Lucasian Professor of Mathematics at the University of Cambridge; Charles Parsons, the inventor of the turbine; Sir John Henry MacFarland, who became Chancellor of Melbourne University; and William McFadden Orr.^[4]

• Hughes, David (2006). "A Bottle of Guinness Please": The Colourful History of Guinness. Phimboy. ISBN 978-0-9553713-0-1.
• Flood, Raymond (2006). "Mathematics in Victorian Ireland". BSHM Bulletin. 21 (3): 200–211. doi:10.1080/17498430600964433. ISSN 1749-8430. S2CID 122564180.

• O'Connor, John J.; Robertson, Edmund F., "John Purser (mathematician)", MacTutor History of Mathematics Archive, University of St Andrews
• Newmann, Kate (2014). "Professor John Purser (1835–1903): Academic and writer". Dictionary Of Ulster Biography. Retrieved 9 June 2017.