Earl of Lucan was a title in the Irish peerage which has been possessed by two related Irish families in creations of 1634 and 1795. The current holder is presumed to be Richard Bingham, 7th Earl of Lucan, who vanished in 1974.

The subsidiary titles associated with the Earldom are: Baron Lucan, of Castlebar in the County of Mayo (created 1776), and Baron Bingham, of Melcombe Bingham in the County of Dorset (1934). The first is in the Peerage of Ireland, the second in the Peerage of the United Kingdom

In 1690, Patrick Sarsfield, who had been one of King James II's senior Irish commanders during his battles in Ireland with William of Orange for the English, Scottish and Irish thrones (see Glorious Revolution) was given the title of Earl of Lucan . Sarsfield's son James Sarsfield died without an heir in 1718 and the title passed out of use.

Patrick Sarsfield's great nephew, Charles Bingham had the title restored in 1795. Due to the long period in which the title was in abeyance, and because legal questions had existed over whether James II was still king when awarding the title and so entitled to enoble Sarsfield, Charles Bingham is usually known as the 1st Earl of Lucan. Patrick Sarsfield is often referred to simply as the Earl of Lucan.

The title became notorious after the disappearance of the 7th Earl in 1974, who is suspected of the murder of his children's nanny. Lord Lucan's son and heir cannot inherit the Earldom until his father is declared legally dead. Thus, whilst Lord Lucan's whereabouts are unknown, his son remains known by his courtesy title, Lord Bingham . In 1999 the High Court, on an application made by the Bingham family, declared Lucan officially dead. Whether he is actually dead or not remains a mystery. In the meantime, Lord Bingham has assumed control of his father's estates, though his efforts to collect ground rent has proved controversial with those previously paid ground rents to the Earls of Lucan but who had not done so since the 7th earl's disappearance.

Earls of Lucan, first Creation (1634)

• Patrick Sarsfield, 1st Earl of Lucan (d. 1693)

Earls of Lucan, second Creation (1795)

• Charles Bingham, 1st Earl of Lucan (1735- 1799)
• Richard Bingham, 2nd Earl of Lucan (1764-1839), elected a Representative Peer in 1800
• George Charles Bingham, 3rd Earl of Lucan (1800-1888), elected a Representative Peer in 1840
• Charles George Bingham, 4th Earl of Lucan (1830-1914), elected a Representative Peer in 1889
• George Charles Bingham, 5th Earl of Lucan (1860-1949), elected a Representative Peer in 1914
• George Charles Patrick Bingham, 6th Earl of Lucan (1898-1964)
• Richard John Bingham, 7th Earl of Lucan (b. 1934)

Heir Apparent: George Charles Bingham, Lord Bingham (b. 1967)