Clossy, Samuel (c. 1724–1786), pioneering anatomist, was born in Dublin, son of Bartholomew Clossy, a prosperous city merchant, and Anne Ogle. After early schooling in Cashel, Co. Tipperary, he entered TCD (1739) under the sponsorship of the eminent Dr William Stephens (d. 1760), and graduated (MB 1751) after an interrupted student career. A period of further study in London facilitated his 1755 MD from TCD and the licence of the Irish College of Physicians, of which he was elected a fellow (1761). Autopsy work in Dr Steevens' Hospital (1752–6) and participation in the influential Medico-Philosophical Society increased his great expertise in pathology, and he contributed articles to Repository. An unofficial attachment to Mercer's Hospital was regularised by a brief staff appointment as physician (1762–3). His prescient Observations on some of the diseases of the parts of the body; chiefly taken from the dissection of morbid bodies (London, 1763) represented one of the first systematic studies of pathology in the English language.
The promise of employment in a projected military hospital precipitated his emigration to New York (September 1763). On learning that the plan had foundered he began lecturing in anatomy within two months of his arrival. This initiative undoubtedly contributed towards his employment by King's College (Columbia University) as a tutor and professor of natural philosophy (October 1765), and he became the college's inaugural professor of anatomy in 1767. Clossy was consequently the first college professor of a medical subject in North America. The disruption of the American war of independence from 1776 and his failing health prompted his return to England in late 1780, but after four years attempting to procure a suitable post he retired on a pension to Dublin, where he died 22 August 1786. His achievements were recognised by his peers in 1784 when he was unanimously elected an honorary fellow of the RCPI. He was survived by his Irish wife, Elizabeth Leech, whom he had married in Dublin (1759), and a daughter; both remained in Ireland during his American sojourn.