Born at 12 Fitzwilliam Square, Dublin, the son of John Crosbie Graves (1776-1835), Chief Police Magistrate for Dublin, by his wife Helena Perceval, the daughter and co-heiress of the Revd Charles Perceval (1751-1795) of Bruhenny, County Cork.
Educated at Trinity College, Dublin from 1829 to 1835, he won a scholarship in Classics.