Thomas Fortescue (1683 – 23 January 1769) was an Irish Member of Parliament.

He was descended from Sir Faithful Fortescue (c.1581–1666), a royalist commander during the English Civil War, a member of the Fortescue family of Buckland Filleigh in Devon, descended from Sir John Fortescue (c.1394-1479), Chief Justice of the King's Bench, of Ebrington Manor, Gloucestershire, a younger grandson of the Fortescue family of Whympston in the parish of Modbury in Devon, the earliest Fortescue seat in England.^[1]

He sat in the Irish House of Commons for Dundalk from 1727 to 1760.

He married Elizabeth Hamilton, a daughter of James Hamilton, a sister of James Hamilton, 1st Earl of Clanbrassil and a granddaughter of John Mordaunt, 1st Viscount Mordaunt, by whom he had children including:

• William Henry Fortescue, 1st Earl of Clermont;
• James Fortescue, an MP and Privy Councillor;
• Charlotte Fortescue, who married Sir Henry Goodricke, 6th Baronet;
• Margaret Fortescue, who married Sir Arthur Brooke, 1st Baronet.

• Clermont, Lord (d.1887), History of the Family of Fortescue in all its Branches, London, 1880

• http://thepeerage.com/p18069.htm#i180688
• leighrayment.com^[usurped]