Luke Kirby (c. 1549 – 30 May 1582) was an English Catholic priest and martyr from the North of England, executed during the reign of Elizabeth I.
Kirby is said to have received his M.A. in England, probably at Cambridge, before converting to Catholicism at Louvain and entering Douai College in 1576. He was ordained a priest at Cambrai in September 1577 and left Rheims for England on 3 May 1578; however, he returned on 15 July and went to Rome. There he took the college oath at the English College, Rome, 23 April 1579. During his stay at the College he practised charity towards his countrymen in Rome who needed help, Catholic and non-Catholic. He helped them from his slender purse, and once went forty miles out of Rome to see some safe on the way. He was chosen to accompany Campion and Ralph Sherwin on their way to England, and the three set out from Rome on 14 April 1580, arriving in Rheims on 31 May. On 16 June he left Rheims with William Hartley. They made the journey to the coast by Douay and Dunkirk on foot.
In June 1580, he was arrested on landing at Dover, and committed to the Gatehouse, Westminster. On 4 December, he was transferred to the Tower, where he was subjected to the torture known as the "Scavenger's Daughter" for more than an hour on 9 December. Luke Kirby was tried at the same time as Edmund Campion, on the same charge of treason against the Queen, but his execution was deferred to the following May, and took place immediately after that of William Filby. Kirby was condemned on 17 November 1581, and from 2 April until the day he died, he was put in irons. With him died Thomas Cottam, and Laurence Richardson. All were later beatified in 1885 by Pope Leo XIII. He was canonized as one of the Forty Martyrs of England and Wales in 1970.