Croker is the only son of John Croker, the surveyor general of customs and excise in Ireland. He is educated at Trinity College, Dublin, where he graduates in 1800. Immediately afterwards he enters Lincoln’s Inn and, in 1802, he is called to the Irish bar.
Croker enters the Parliament of the United Kingdom in 1808 as member for Downpatrick, obtaining the seat on petition, though he had been unsuccessful at the poll. In 1810 he is appointed to the office of First Secretary to the Admiralty, which he holds without interruption under various administrations for more than twenty years. From the beginning he has the backing of Arthur Wellesley, 1st Duke of Wellington, and the friendship continues between them until Wellesley’s death in 1852.
Strongly opposed to the Representation of the People Act 1832, Croker resigns from Parliament when it is passed, though he continues thereafter his close contacts with Tory leaders. From about this period there begins a lifelong antagonism between Croker and Thomas Babington Macaulay, 1st Baron Macaulay, a major champion of the Reform Bill and Whiggism.
From 1831 to 1854 Croker is one of the chief writers for the Quarterly Review, to which he contributes about 270 articles on a variety of subjects. His literary tastes are largely those of the 18th century, as may be seen from his severe criticism of John Keats’s Endymion, Alfred Tennyson’s Poems of 1832, and of course the first two volumes of Macaulay’s The History of England from the Accession of James the Second (1848). For some years before his death he accumulates material for an annotated edition of Alexander Pope’s works. This is passed to Whitwell Elwin, who begins the edition later completed by William John Courthope. Croker also edits the collected letters or memoirs of various 18th-century figures.
Croker dies at the age of 76 on August 10, 1857 at St. Albans Bank, Hampton.
(Pictured: Portrait of John Wilson Croker, by William Owen (died 1825), given to the National Portrait Gallery, London in 1872)