Johnstone, John Henry (1749–1828), actor and singer, was born 1 August 1749 in Co. Kilkenny, son of a quartermaster in an Irish regiment of horse; there are few details about the rest of his family. His father died when he was a child and he was supported by his mother, who sold second-hand clothes for a living. In 1761 he became the apprentice of a Mr Jones, a Dublin attorney, and worked for five years as his clerk. However, after a serious disagreement, he left this employment and went to England, where he quickly squandered his money. Fortunately he encountered a merchant who was an old family friend, from whom he borrowed enough money to return home. While in Athlone, Co. Westmeath, he joined the army to avoid the attentions of a troublesome bailiff. After serving with a cavalry regiment at Clonmel, Co. Tipperary, he embarked on a career on the stage (1775); it seems he was discharged from the army for a combination of ungallant amorous adventures and insubordination.
Making his debut at the Smock Alley Theatre on 9 November 1775, he appeared as the singing lover, Lionel, in ‘Lionel and Clarissa’. An immediate success, he was soon a regular in this kind of role and performed at Crow St., Fishamble St., and Smock Alley, as well as on regional tours of Cork (1777, 1779, and 1781) and Kilkenny (1780). He married (22 February 1778) Maria Ann Poitier, actress and daughter of Col. Charles Poitier, governor of Kilmainham jail. While in London visiting his mother-in-law, he was engaged by Thomas Harris at Covent Garden on a weekly salary of £8 (in addition his wife was hired with a salary of £4). Making his debut as Lionel on 2 October 1783, he was praised by the Theatrical Review for his elegant voice and eminent style. His performance as Dermot in the comic opera ‘The poor soldier’, by John O'Keeffe (qv), was so successful that afterwards London operas often included an Irish character to showcase his talents. In fact many playwrights began writing scenes for an Irishman in their work, no matter how incongruous to the plot, to increase the chances of getting it performed. Soon Johnstone was regarded as the finest stage Irishman of the era, and played Edwin in the premiere of ‘Robin Hood’ (1784), which had a libretto by Leonard MacNally (qv). Embroiled in a public affair with the actress Sarah Maria Wilson, he separated from his wife, who died on 15 June 1784; Wilson herself died two years later. Despite his private travails, his professional career prospered and he excelled playing Irish characters or roles for first-tenors in comic operas. Occasionally he returned to Ireland for lucrative tours of Dublin and the provinces, for example in 1785, 1788, and 1790. On 23 December 1791 he married Ann Bolton, the daughter of a wine merchant. A serial adulterer, it seems he was also a parsimonious husband, and his wife was sometimes required to pawn her clothes for money; she died on 19 August 1810. He retired from the stage around 1793, but sometimes performed at benefits in his honour. On a visit to Dublin in 1803 he was hailed as the exemplar of a genuine Irishman, and he returned to the stage in Drury Lane, London, on 20 September as Murtock Delany in ‘The Irishman in London’. He died 28 December 1828 at his home at 5 Tavistock Row, London, and was buried at St Paul's, Covent Garden. His estate was valued at £12,000.
Johnstone had one daughter, Susan (c.1793–1851), from his second marriage. She was briefly on the stage and married the popular actor James William Walleck the elder (1794–1864); their children formed a distinguished theatrical dynasty in England, which included John Johnstone ‘Lester’ Walleck (1819–88). He also had a daughter from one of his numerous affairs, Jemima Marian Bew, who married the actor Frederick Vining.