John Butler, 17th Earl of Ormonde, 10th Earl of Ossory (1740–1795) was an Irish peer and Member of Parliament (MP). He became a Protestant in 1764. He was an Irish MP, representing Gowran between 1776 and 1783, and Kilkenny City between 1783 and 1792. In 1791, his right to the peerage was acknowledged in the Irish House of Lords and he became the 17th Earl of Ormond.

Butler is the name of a noble family whose members were, for several centuries, prominent in the administration of the Lordship of Ireland and the Kingdom of Ireland. They rose to their highest prominence as Dukes of Ormonde. The family has produced multiple titles such as Baron Cahir, Baron Dunboyne, Viscount Ikerrin, Viscount Galmoye, Viscount Mountgarret, Viscount Thurles, Earl of Carrick, Earl of Kilkenny, Earl of Ormond, Earl of Ossory, Marquess of Ormonde and Duke of Ormonde. Variant spellings of the name include le Boteler and le Botiller. The Butlers were descendants of Anglo-Norman lords who participated in the Norman invasion of Ireland in the 12th century. The surname has its origins in the hereditary office of "Butler (cup-bearer) of Ireland", originating with Theobald Walter, 1st Chief Butler of Ireland. The arms of later family members depicted three cups in recognition of their original office.