Viscount Charlemont is a title in the Peerage of Ireland. It was created in 1665 for William Caulfeild, 5th Baron Charlemont.
The Caulfeild family descends from Sir Toby Caulfeild, originally of Oxfordshire, England. He was a noted soldier and also represented Armagh in the Irish House of Commons. In 1620 he was created Lord Caulfeild, Baron of Charlemont, in the Peerage of Ireland, with remainder to his nephew Sir William Caulfeild, who succeeded him as second Baron. The latter's son, the third Baron, was shot in 1642 on the orders of Sir Phelim O'Neill, the leader of the Irish Rebellion of 1641. His younger brother, the fifth Baron, had O'Neill apprehended and executed for the murder of his elder brother. In 1665 he was created Viscount Charlemont in the Peerage of Ireland. His son, the second Viscount, was an opponent of King James II and attainted, but was later restored by King William III. His son, the third Viscount, represented Charlemont in the Irish Parliament. He was succeeded by his son, the fourth Viscount. In 1763 he was created Earl of Charlemont in the Peerage of Ireland. His eldest son, the second Earl, sat in the House of Lords as an Irish Representative Peer from 1806 to 1837. The latter year he was created Baron Charlemont, of Charlemont in the County of Armagh, in the Peerage of the United Kingdom, with remainder to his younger brother the Hon. Henry Caulfield and the heirs male of his body. Lord Charlemont later served as Lord Lieutenant of County Tyrone from 1839 to 1863. He was succeeded by his nephew (in the barony of 1837 according to the special remainder), the third Earl. He sat as a Liberal Member of Parliament for Armagh from 1847 to 1867 and also served as Lord Lieutenant of County Armagh from 1849 to 1864 and of County Tyrone between 1864 and 1892.