"Actor and orthoepist, was probably born in early 1719, though no records of birth or baptism have been found. His father, Dr Thomas Sheridan (1687–1738), was by then running a highly regarded school at his house in Capel Street, Dublin, but there is a possibility that Thomas, his third son, was born in Quilca, co. Cavan, perhaps in the childhood home of his mother, Elizabeth MacFadden. Jonathan Swift, a close friend of Dr Sheridan, was Thomas's godfather and, by Sheridan's own account, a beneficent influence on him from childhood."
Worked as an actor in Dublin from 1743 and in London from 1744. Developed a friendhip with David Garrick. Theatre manager from 1745.
Published a book British Education (1756), and lectured on spoken English. This was followed by discourses on the theatre, education and English language (1759-62), his Dictionary in 1780, and a 17 vol edition of Swift's works (1784).
(Source: Peter Thomson, DNB: doi:10.1093/ref:odnb/25371)