Abernethy, William (1864–1930), professional photographer, was the son of Robert Abernethy, farmer, from Comber, Co. Down. Details of his early life are lacking, even in obituaries published in the Belfast press. He learned his trade in Belfast, in the studio of a successful portrait photographer, John Phillips. In 1886 he married Elizabeth McClurg and in the same year, when aged only 22, opened his own studio at a good address in the High Street. He soon became the leading portrait photographer of his generation in Belfast, partly because he was a skilled practitioner of his craft but also because he had an excellent head for business. In a description of his studio published in 1891 he claimed to be employing upwards of twenty experienced assistants of various kinds and photographing on average more than 300 clients a day; a later advertisement, dated 1895, boasted of having taken 18,000 portraits during the previous year. Expanding his operations, by 1910 he had three branch studios in Belfast, as well as others in Bangor, Newry, and Dundalk. Abernethy's standing was officially recognised in 1900, when Queen Victoria, during her visit to Ireland, allowed him to photograph her and awarded him the royal warrant. In 1925, when a Northern Ireland branch of the London-based Professional Photographers' Association was formed, Abernethy was elected president.
Financially successful, Abernethy could afford to support a comfortable lifestyle. His two sons were sent to boarding school, after which one went on to university to read medicine, the other to attend the Slade School of Art. Of his three daughters, one was an early woman graduate of TCD and became headmistress of a Dublin school for girls. Abernethy and his wife travelled extensively for pleasure, he himself venturing as far as the Holy Land. When he died, at his home in Bangor on 23 February 1930, his estate was valued at £6,350. The business, run by his sons during the 1930s and later by his widow (through a manager) declined, closing eventually in the 1950s. A portrait of Abernethy by the artist Harry Douglas, appropriately a photograph overpainted in oils, is in the possession of descendants.