John Bourke, 1st Earl of Mayo (English: /bɜːrk/; BURK; circa 1705 – 1790), styled Lord Naas (/neɪs/; NAYSS) from 1775 to 1781 and Viscount Mayo from 1781 to 1785, was an Irish politician and peer who was MP for Naas (1727–60, 1768–72) and Old Leighlin (1760–68) and was created Earl of Mayo (1785).

He was the son of Richard Bourke (d.1727) and Catherine Minchin, daughter of Charles Minchin of Ballynakill, County Tipperary. He was descended from Gaelic nobles, and shared a common ancestor with Tibbot ne Long Bourke, 1st Viscount Mayo. He was educated at Trinity College, Dublin.^[1][2]

In 1727, he was elected as the Member of Parliament for Naas, representing the seat in the Irish House of Commons until 1760. Between 1761 and 1768 he served as MP for Old Leighlin. He was re-elected for Naas in 1768, and held the seat until his elevation to the peerage in 1776. That year was created Baron Naas, of Naas in the County of Kildare, in the Peerage of Ireland.^[3] He assumed his seat in the Irish House of Lords, and on 13 January 1781 he was made Viscount Mayo, a title which had previously been held by his distant relations. On 24 June 1785 Bourke was made Earl of Mayo.^[3]

Bourke married Mary Deane (d.1774), daughter of Joseph Deane and Margaret Boyle, in 1726.^[3] Together they had three children. The Naas constituency was also represented by Bourke's son and grandson, the second and fourth earls.

Coat of arms of John Bourke, 1st Earl of Mayo

Crest A Cat-a-Mountain sejant guardant proper, collared and chained Or. Escutcheon Party per fess Or and Ermine, a cross gules the first quarter charged with a lion rampant sable and the second with a dexter hand couped at the wrist and erect gules Supporters On either side a Chevalier in complete Armour, holding in the exterior hand a Pole-Axe, all proper.[4][5] Motto A CRUCE SALUS (Salvation from the Cross)

• House of Burgh, an Anglo-Norman and Hiberno-Norman dynasty founded in 1193

• Burke, Bernard (1884). The General Armory of England, Scotland, Ireland, and Wales; comprising a registry of armorial bearings from the earliest to the present time. University of California Libraries. London: Harrison & Sons.
• Burtchaell, George Dames; Sadleir, Thomas Ulick (1935). Alumni Dublinenses: A Register of the Students, Graduates, Professors and Provosts of Trinity College in the University of Dublin (1593–1860). Dublin: Alex Thom and Co.
• Cokayne, G. E. (1893). The Complete Peerage of England, Scotland, Ireland, Great Britain, and the United Kingdom Extant, Extinct, or Dormant (1st ed.). London: George Bell & Sons.
• Debrett, John (1838). Courthope, William (ed.). Debrett's Complete Peerage of the United Kingdom of Great Britain and Ireland (22nd ed.). London: J. G. & F. Rivington. p. 566.
• Mosley, Charles, ed. (2003). Burke's Peerage, Baronetage & Knighthood (107 ed.). Burke's Peerage & Gentry. ISBN 0-9711966-2-1.