Knowles, James (1759?–1840), lexicographer, was born in Cork, the son of John Knowles of Dublin, and his wife Frances, daughter of Thomas Sheridan (qv) (1687–1738) of Quilca, and sister of Thomas Sheridan (qv) (1719–88). His cousin was Richard Brinsley Sheridan (qv). After a good education, Knowles married young, thus forfeiting the possibility of attending university, and had to set up a school to support his family. Injudicious support for liberal politics and for catholic rights upset the parents of his protestant pupils, and he was forced to close the school.
After a spell in London, and later in Sidcup, Kent, where he was a schoolmaster, he was appointed (1814) first headmaster of the English school, part of the Belfast Academical Institution. The Board of the school had first approached Knowles's son James Sheridan Knowles (qv), who ceded the position to his father and then, though they constantly fought, worked as his assistant. Knowles senior was a failure in the post: for the next two years his behaviour was the subject of complaints to the board, which censured him in 1816 for attending a St Patrick's day dinner where anti-government political speeches were made. Knowles did not accept that the board had the right to discipline him, and published a lengthy self-vindication in the Belfast Commercial Chronicle. The historian of RBAI notes that Knowles displayed a mixture of ‘truculence, petulance, tactlessness, bravado and downright viciousness’, and in July 1817, when the board demanded Knowles's resignation, he characteristically refused to cooperate and was then dismissed. His response was to publish an angry and intemperate pamphlet, Appeal to the . . . proprietors of the Belfast Academical Institution (1820), and he refused to give up the schoolmaster's house to his successor until a board member took him by the arm and led him out. Knowles returned to London, and established himself as an elocution teacher; along with his son, he published in 1829 a book on proper pronunciation, Orthœpy and elocution. In this he followed in the footsteps of his uncle Thomas Sheridan. When an old man, he began work on A pronouncing dictionary . . ., which appeared in 1835. After a protracted dispute with a printer over his book, James Knowles died 6 February 1840 in his son's house off Bedford Square, London, and was buried in Highgate cemetery.
He married first Jane Daunt (née Peace; d. 1800) of Cork, who had been widowed as a young woman with a young daughter. Her first husband may have been related to the Knowles family; her father was Andrew Peace, a doctor. She and James Knowles had two daughters and a son. Knowles's second wife was a Miss Maxwell.