Born in Lisburn, Ireland, McCloy studied at the School of Design in Belfast while serving an apprenticeship in engraving. He then spent a year at the Central School, Somerset House in London before being appointed Master of the Waterford School of Art. He returned to Belfast in 1875 and remained there until 1881 when he moved to London. He exhibited at the Royal Hibernian Academy between 1862 and 1882 as well as in numerous London exhibitions from 1859 to 1891. McCloy was married to a Waterford artist, E. L. Harris.