Relhan, Anthony (1715–76), physician, was born in Dublin, son of Anthony Relhan, merchant, and Margaret Relhan (d. 1750). Educated at Dr Sheridan's school in Dublin, he entered TCD in November 1730, was made a scholar (1734) and graduated BA (1735). Deciding on a career as a physician, he entered (October 1740) the university at Leiden, where he carried out his medical training. A prominent freemason, he was elected as grand secretary of the freemasons of Ireland in 1742.
He graduated MB and MD from TCD (1743) and soon acquired a reputation as one of the best physicians in Dublin. In October 1747 he was elected as a fellow of the K&QCPI (later renamed as the RCPI). Appointed as physician to the Meath Hospital, in 1755 he was elected as president of the King and Queen's College. He took up the presidency at a difficult time. Sir Patrick Dun (qv) had bequeathed the contents of his large medical library to the college under the terms of his will. In 1755 the college still had not incorporated Dun's collection into their own library, and the books were either in storage or scattered among the libraries of various fellows. Relhan was called before a committee of the Irish house of lords to explain this state of affairs, and he claimed that the college lacked the funds to build a new library to house the collection.
In 1758 he had a major falling-out with his medical colleagues in Dublin. He prescribed James's Powders, a patent medicine marketed by an English physician, Dr Robert James, who kept the ingredients secret. Relhan's colleagues criticised him severely for advocating the use of what they saw as quack medicine. Fellows of the college refused to sit in consultation with him and he began a correspondence with James about the possibility of moving to England. In December 1759 Dr Russell of Brighton died and Relhan took over his practice, which mainly catered for invalids who had come to the seaside town to convalesce. He published A short history of Brighthelmstone: its air and its waters (1761), in which he not only gave an account of the town but promoted it as a spa resort. In June 1763 he became a candidate at the Royal College of Physicians in London and was elected as a fellow in 1764. He was a prominent advocate of inoculation, and published Refutation of the reflections against inoculation (1764). His association with the RCP (London) was to be a happy one and he maintained a thriving practice in Brighton. In 1765 he served as a college censor and was elected as Gulstonian lecturer. He was elected as Harveian lecturer in 1770, publishing his lecture as Oratio ex Harveii in 1771, and acting again as college censor in the same year. He died in London in October 1776 and was buried in the Marylebone graveyard in Paddington St.
He married first (December 1746) Sarah Breholt; they had one son – Richard Relhan, clergyman, botanist, and author – and one daughter. While living in Dublin they had a residence in George's Lane. His second wife was the widow of Sir William Hart, a London banker, whom he met at Brighton.