Gardner, Sir Robert (1838–1920), accountant, was born 14 April 1838 in Kilrea, Co. Londonderry, one of six children (three boys and three girls) of John Gardner, a shopkeeper, and Sarah Gardner (née Taggart). John Gardner moved to Ballymoney, Co. Antrim, where Robert was educated before he went to Dublin and started to practise as an accountant with Brown, Craig & Co. in 1856. In 1861 he married Sarah Dale (d. 1877) of Larne, Co. Antrim, with whom he had three sons and two daughters. On Henry Brown's departure from Brown, Craig & Co. in 1866, Gardner entered into partnership with William G. Craig and formed Craig, Gardner & Co., with offices at 40 and 41 Dame Street, Dublin. Despite Craig's mental instability, which led to his early exit from the firm, it prospered and as Craig, Gardner & Harris, opened offices in Belfast and London. Before long Gardner became the pre-eminent accountant in Ireland and was auditor to many of the leading businesses and enterprises of the day, including the Provincial Bank of Ireland (from 1882), the Royal Bank of Ireland (1881–5), Belfast Banking Co. (from 1883), the National Bank, and many other important Irish companies.
Gardner's accountancy practice brought him into contact with many of the successful businessmen of the time. In April 1880 he married Jane (‘Jennie’) Johnston (d. 1893), daughter of John B. Johnston (d. 1883) of Clyde Road, Dublin, who owned a bakery and milling business; they had a son and a daughter. At the same time John Findlater (qv) was married to a relative of Jennie, and when Johnston died in 1883 Gardner and Findlater brought in brothers Joseph and William O'Brien, bakers, and John Mooney, miller, to form the bakery Johnston, Mooney & O'Brien. Findlater was the first chairman, and the board of directors included Gardner, the O'Brien brothers, Mooney, Joseph Todhunter Pim, and John Malcolm Inglis.
In 1888 Gardner was a leading light in the establishment of the Institute of Chartered Accountants in Ireland and served as its first president and a member of council (1888–90). Considered by many to be both despotic and impetuous, he resigned from the institute on 7 May 1890 owing to criticism of his employing an English firm of accountants for the formation of Johnston, Mooney & O'Brien. Despite this setback he remained at the forefront of the profession in Ireland. His directorships included that of the Carlton Hotel, London. In civic affairs Gardner was a diligent chairman (from c.1903) of Pembroke township, a JP, and high sheriff of Co. Dublin (1914). He was knighted in July 1905.
After the death of his second wife, Gardner married, on 21 November 1895, Norah Kathleen Peacocke (d. 1956), daughter of Captain Peter Leslie Peacocke, 16th lancers, of Villagio, Dalkey, Co. Dublin. They had three daughters. Gardner died 24 November 1920 at his home, Ashley, Clyde Road, Dublin.