Earl of Howth
Earl of Howth was a title in the Peerage of Ireland. It was created in 1767 for Thomas St Lawrence, 15th Baron Howth, who was elevated to Viscount St Lawrence at the same time, also in the Peerage of Ireland. The St Lawrence family descended from Christopher St Lawrence who was elevated to the Peerage of Ireland as Baron Howth in circa 1425. The third and fourth Barons both served as Lord Chancellor of Ireland.
The fourth baron was also a distinguished soldier who fought at the Battle of Knockdoe; his grandson the seventh baron was also a notable soldier. The eighth baron, commonly known as "the blind lord", led the opposition to the Government's taxation policy in the 1570s. The ninth baron was openly Roman Catholic, and led opposition to the Penal Laws in the early 1600s. The tenth baron was a notable military commander who served with the Earl of Essex and Lord Mountjoy. The fourteenth Baron represented Ratoath in the Irish House of Commons, and was a friend of Jonathan Swift. The third Earl served as Lord-Lieutenant of Dublin. 
The fourth Earl sat as Member of Parliament for Galway Borough, and in 1881 he was created Baron Howth, of Howth in the County of Dublin, in the Peerage of the United Kingdom. All these titles became extinct upon his death in 1909 as he left no male heir. The family seat, Howth Castle, still belongs to their descendants in the female line, the Gaisford-St Lawrence family. 
Barons Howth (c. 1425)
- Christopher St Lawrence, 1st Baron Howth (died 1430)
- Christopher St Lawrence, 2nd Baron Howth (died 1465)
- Robert St Lawrence, 3rd Baron Howth (died 1485)
- Nicholas St Lawrence, 4th Baron Howth (died 1526)
- Christopher St Lawrence, 5th Baron Howth (died 1542)
- Edward St Lawrence, 6th Baron Howth (1508–1549)
- Richard St Lawrence, 7th Baron Howth (died 1558)
- Christopher St Lawrence, 8th Baron Howth (died 1589)
- Nicholas St Lawrence, 9th Baron Howth (1555–1606)
- Christopher St Lawrence, 10th Baron Howth (died 1619)
- Nicholas St Lawrence, 11th Baron Howth (1597–1643)
- William St Lawrence, 12th Baron Howth (died 1671)
- Thomas St Lawrence, 13th Baron Howth (1659–1727)
- William St Lawrence, 14th Baron Howth (1688–1748)
- Thomas St Lawrence, 15th Baron Howth (1730–1801; created Earl of Howth in 1767)
Earls of Howth (1767)
- Thomas St Lawrence, 1st Earl of Howth (1730–1801)
- William St Lawrence, 2nd Earl of Howth (1752–1822)
- Thomas St Lawrence, 3rd Earl of Howth (1803–1874)
- William Ulick Tristram St Lawrence, 4th Earl of Howth (1827–1909)
- Ball, F. Elrington History of Dublin Alexander Thom and Co 1917 Vol. 5
- Ball History of Dublin
- "St. Lawrence, Robert". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.
- "St. Lawrence, Nicholas". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.
- "St. Lawrence, Christopher (1568?-1619)". Dictionary of National Biography. London: Smith, Elder & Co. 1885–1900.