Laurence Clinch (c. 1740-1812) was an Irish actor, familiarly known as Larry, and accomplished in both tragedy and comedy. The popular farce St Patrick's Day was written and performed to showcase his particular talent.

A native of Dublin, Clinch gave his first professional stage performances in February 1768 when, billed as "A Young Gentleman", he appeared at the Crow Street Theatre in Henry Mossop's productions of Thomas Otway's The Orphan and Venice Preserved as, respectively, Castalio and Jaffier. He was considered well suited to the roles of such tragic lovers, "his figure being tall, well-made and pleasing, his voice powerful and melodious, and his manner compounded of the modest and agreeable". Such attributes also recommended him for the part of Lothario in Nicholas Rowe's The Fair Penitent, which he played in the following May.

In 1769 he was cast by Mossop in Thomas King’s Wit's Last Stand and Charles Johnson's The Country Lasses and demonstrated a talent for comedy that sprang from his own light-hearted nature, later recalled by the actor Michael Kelly's characterisation of him as "the facetious Larry Clinch". In the same year he played Edgar in King Lear and had the spoken title-role in Mossop's production of the semi-opera King Arthur.

When Mossop's financial difficulties resulted in disbandment of his company, Clinch was engaged by Thomas Dawson and Robert Mahon who had undertaken management of Dublin's Capel Street Theatre. He played for them in the 1770-1771 season alongside Charles Macklin, William Thomas Lewis, John O'Keeffe and Elizabeth Younge, and in 1772 he ventured to England.

After performing in Norwich, he was engaged by David Garrick at Drury Lane and in October 1772 appeared there in the title-role in Nathaniel Lee’s Alexander the Great. On that occasion he was criticised for insufficient attention to "the dignity of blank verse" but, subject to correcting such deficiency, was forecast to be "a very considerable acquisition to the theatrical world". That he was "a young actor well worthy the patronage of the public" was acknowledged when, in March 1773, he played Alberto in the first production of John Home's tragedy Alonzo, but shortly afterwards he fell out with Garrick.

The pair had been on sufficiently warm terms that Clinch was allowed the freedom of Garrick's box at Drury Lane. One evening he entered the box when the manager was seated at the front with several ladies and, sensing the private nature of the occasion, he remained at the back waiting to leave the box when the current scene concluded. Becoming aware of his presence, Garrick rose and removed the hat from Clinch's head, pointing to the presence of ladies. An embarrassed Clinch withdrew and sent Garrick a note requesting an apology or a meeting. An apology was forthcoming, but Garrick did not renew his contract.

He made several appearances at the Theatre Royal in King Street, Bristol, in August and September 1773, including a benefit performance in the title-role in Arthur Murphy's Alzuma. Returning to Ireland, he acted at Cork and Limerick in 1774, but then resumed his career in London where he joined Richard Brinsley Sheridan's company at Covent Garden. His friendship with Sheridan's actor father, with whom he had played in Dublin, may have been influential in his obtaining this engagement.

In the autumn of 1774 his portrayal of Alexander the Great was considered a qualified improvement on his appearance in the part two years earlier ("he gave the passion utterance more naturally than before but he was extremely deficient in the tender scenes"). However, his later performances as Richmond in Shakespeare's Richard III and as Pharamond in Beaumont and Fletcher's Philaster were commended and he was thought to have "caught the manner" (if not the "persuasive delivery") of Spranger Barry, with whom he had appeared in Murphy's The Grecian Daughter somewhat earlier.