Carroll, John (1903–86), agricultural zoologist, was born 4 April 1903 in Bantry, Co. Cork, eldest of two sons and five daughters of John Carroll (d. 1955), land steward and cattle dealer, of Crookstown, Kilmurry, Co. Cork, and Julia Carroll (née Cunningham), also of Crookstown. Educated at Belvelly national school, Co. Cork, Howth national school, Co. Dublin, and O'Connell CBS, North Richmond St., Dublin, he won a Department of Agriculture scholarship to attend the Royal College of Science, which was subsumed into UCD during his time there. He held a position as a demonstrator in agricultural zoology in UCD briefly in 1925 before further scholarships took him to the Imperial College of Science, London, and Cornell University, USA, where he gained respectively a DIC (Diploma of Imperial College) and an MS (Master of Science). In 1928 he returned to UCD as research assistant in agricultural zoology while also being employed as an advisor on pest control by the Department of Agriculture. He became lecturer (1937), professor (1954), and dean of the faculty of agriculture from 1958 until his retirement in 1968. He was a frequent contributor to Agricultural Ireland and other journals, receiving from the NUI his D.Sc. (1939) on the basis of published work. He was elected MRIA (1959) and received an honorary LLD from the NUI (1979).
In his self-published autobiography, Most of the century (1983), he recounts with pride his non-academic achievements. In 1929 he became a member of the RDS, an organisation of which he became president (1977–80). He was also president of the Royal Zoological Society (1974–5) and the Agricultural Science Association (1953–5) and twice chairman of the Irish Building Societies Association. The latter position was a result of his association with the Educational Building Society (EBS). Through his friendship with Alasdair Mac Caba (qv) he became a board member of the EBS in 1941, succeeding to the chairmanship in 1967. He was a member of the Knights of St Columbanus from 1929 and was associated with similar orders later in life. He died at St Vincent's private nursing home, 9 August 1986, leaving an estate of £125,309.
He married (1933) Hilda, daughter of John Mathews, teacher, of Howth, Co. Dublin. They had three sons and three daughters. A portrait by James Le Jeune is in the agriculture and food building at UCD.