McCarthy, Karl (1928–95), cyclist, was born in Cork and educated at North Monastery School, Cork, and UCC. He graduated in 1952 with a degree in biochemistry and chemistry and continued his studies, receiving two years later an M.Sc. degree in organic chemistry. On leaving college he worked for a short time in Beamish & Crawford in Cork as a brewer improver. In 1955 he moved to Yorkshire and began working as a brewery chemist. Three years later he received a certificate of biochemical engineering from Manchester College of Technology. In 1959 he began working as a brewer in Ind Coope and Allsop at Burton on Trent. He was appointed assistant to the chief chemist at Truman Hanbury & Buxton in London (1961). An independent-minded and dogged character, he returned to Ireland (1965) and set up his own company, Biocel Ltd, in Little Island, Co. Cork.
His cycling career spanned from 1943 to 1956. In 1951–4 he won the Ireland team trial championships on grass and hard tracks. He broke the Irish 100-mile (160.9 km) track record on three occasions and was the first Irish amateur to be placed in an international stage in the Tour of Britain (1951). He served as president and international secretary of the Irish Cycling Federation. A lifelong member of St Finbarr's Cycling Club in Cork, he was also its president for a time. For a number of years he was an organiser of the Tour of Ireland Cycle Race and organised many races in Cork – for instance, the Cork 800, an international race held in the anniversary year 1985. He died 3 August 1995 at the Mercy Hospital, Cork.
He lived in St Christopher's Road, Montenotte, Cork, with his wife Terry, their daughter, and their three sons.