He was educated for the Roman Catholic priesthood; but after his ordination (1800) religious doubts led him to escape from Spain to England (1810), where he ultimately entered the Anglican Church, having studied theology at Oxford and made the friendship of Arnold, Newman and Whately. He became tutor in the family of the last-named when he was made archbishop of Dublin (1831). While in this position he embraced Unitarian views; and he found an asylum amongst the Unitarians of Liverpool, where he died on the 20th of May 1841.
White edited El Español, a monthly Spanish magazine in London, from 1810 to 1814, and afterwards received a civil list pension of £250. His principal writings are Doblado's Letters from Spain (1822); Evidence against Catholicism (1825); Second Travels of an Irish Gentleman in Search of a Religion (2 vols., 1834); Observations on Heresy and Orthodoxy (1835). They all show literary ability, and were extensively read in their day.
He also translated Paley's Evidences and the Book of Common Prayer into Spanish. He is best remembered, however, by his sonnet "Night and Death" ("Mysterious Night! when our first parent knew"), which was dedicated to ST Coleridge on its appearance in the Bijou for 1828 and has since found its way into several anthologies. Three versions are given in the Academy of September 12, 1891.
See Life of the Rev. Joseph Blanco White, written by himself, with portions of his Correspondence, edited by John Hamilton Thom (London, 3 vols., 1845).