The title Earl of the County of Mayo, usually known simply as Earl of Mayo, was created in the Peerage of Ireland in 1785 for John Bourke, 1st Viscount Mayo . The subsidiary titles held by Lord Mayo are Viscount Mayo, of Moneycrower in the County of Mayo (created 1781), and Baron Naas, of Naas in the County of Kildare (1776). The courtesy title of Lord Mayo's eldest son and heir is Lord Naas (pronounced "Nace").

Earls of Mayo (1785)

• John Bourke, 1st Earl of Mayo (c. 1705-1790)
• John Bourke, 2nd Earl of Mayo (c. 1735-1792)
• Joseph Deane Bourke, 3rd Earl of Mayo (c. 1740-1794)
• John Bourke, 4th Earl of Mayo (1766-1849), elected a Representative Peer in 1816
• Robert Bourke, 5th Earl of Mayo (1797-1867), elected a Representative Peer in 1852
• Richard Southwell Bourke, 6th Earl of Mayo (1822-1872)
• Dermot Robert Wyndham Bourke, 7th Earl of Mayo (1851-1927), elected a Representative Peer in 1890
• Walter Longley Bourke, 8th Earl of Mayo (1859-1939)
• Ulick Henry Bourke, 9th Earl of Mayo (1890-1962)
• Terence Patrick Bourke, 10th Earl of Mayo (b. 1929)

Heir Apparent: Charles Diarmuidh John Bourke, Lord Naas (b. 1953) Lord Naas's Heir Apparent: Richard Thomas Bourke (b. 1985)