John Robert William Vesey, 4th Viscount de Vesci (21 May 1844 – 6 July 1903) was an Anglo-Irish peer and British Army officer.
Vesey was the son of Thomas Vesey, 3rd Viscount de Vesci and Lady Emma Herbert. In 1863 he was commissioned into the Coldstream Guards. He was promoted to captain in 1866, and to lieutenant-colonel in 1876. On 23 December 1875 he succeeded to his father's titles in the Peerage of Ireland. He retired from the army in 1883. On 8 November 1884 he was created Baron de Vesci, of Abbey Leix in the Queen's County in the Peerage of the United Kingdom, thus giving him a seat in the House of Lords. Between 1883 and 1900 he served as Lord Lieutenant of Queen's County.
On 4 June 1872 Vesey married Lady Evelyn Charteris, the eldest daughter of Francis Charteris, 10th Earl of Wemyss and Lady Anne Frederica Anson. They had one daughter, Mary Gertrude, who married Hon. Aubrey Herbert, second son of Henry Herbert, 4th Earl of Carnarvon. On his death in 1903, his British peerage became extinct while his Irish titles were inherited by his nephew, Yvo Vesey.