Earl of Leitrim (pronounced "Leetrim") was a title in the Peerage of Ireland. It was created in 1795 for Robert Clements, 1st Viscount Leitrim. He had already been created Baron Leitrim, of Manor Hamilton in the County of Leitrim, in 1783, and Viscount Leitrim in 1793, also in the Peerage of Ireland. In 1800 he was elected as one of the 28 original Irish Representative Peers. Lord Leitrim was the son of the influential politician and financier Nathaniel Clements. He was succeeded by his son, the second Earl. He was created Baron Clements, of Kilmacrenan in the County of Donegal, in the Peerage of the United Kingdom in 1831, which gave him and his descendants an automatic seat in the House of Lords. His eldest son Robert Clements, Viscount Clements, represented County Leitrim in Parliament. However, he predeceased his father, unmarried. Lord Leitrim was succeeded by his second son, the third Earl. He also sat as Member of Parliament for County Leitrim. A deeply unpopular landlord, Lord Leitrim was murdered along with his clerk and driver while on his way to his residence in Milford in 1878. He was unmarried and was succeeded by his nephew, the fourth Earl. He was the son of the Reverend the Hon. Francis Nathanial Clements, fifth and youngest son of the second Earl. Lord Leitrim served in the Royal Navy. He was succeeded by his eldest son, the fifth Earl. He served as Lord-Lieutenant of the City of Londonderry. He was twice married but childless. As Lord Leitrim's two younger brothers had both died unmarried before him the titles became extinct on his death in 1952.
The Honourable Charles Clements, third son of the second Earl, was Member of Parliament for County Leitrim. Henry Clements, brother of the first Earl, represented Cavan Borough in the Irish House of Commons. Theophilus Clements, uncle of the first Earl, represented County Cavan in the Irish Parliament. The heir apparent to the earldom used the invented courtesy title Viscount Clements.
The family seat of the Earls of Leitrim was Lough Rynn, near Mohill, County Leitrim. Lough Rynn has recently been restored and currently functions as a luxury hotel and resort. The 4th and 5th Earls of Leitrim, however, used mainly Mulroy House, near Letterkenny, County Donegal, as their residence.