Thomas St Lawrence, 1st Earl of Howth (10 May 1730 – 29 September 1801) was Anglo-Irish peer and lawyer.
In 1776, the Crown granted Howth a yearly pension of £500 in consideration of his own and his ancestors' services.
On 3 September that same year he was created Earl of Howth and Viscount St Lawrence, both in the Peerage of Ireland.
The Earl's eldest daughter, the third Isabella, married Dudley Cosby, 1st Baron Sydney, in 1773, but was widowed almost at once.
The youngest daughter, Frances, married as his second wife James Phillott, Archdeacon of Bath, a marriage which gave rise to caustic comments from Jane Austen about the desperation of Frances, who was well over forty, to find a husband of any description (Phillott being almost sixty at the time, and a widower).