Thomas Vesey, 1st Viscount de Vesci (died 13 October 1804) was an Anglo-Irish peer.
Vesey was the son of John Vesey, 1st Baron Knapton and Elizabeth Brownlow. He succeeded to his father's peerage in 1761, and assumed his seat in the Irish House of Lords. On 19 July 1776 he was made Viscount de Vesci, of Abbeyleix in the Queen's County in the Peerage of Ireland.
On 24 April 1769 he married Selina Elizabeth Brooke, the eldest daughter and co-heriress of Sir Arthur Brooke, 1st Baronet. he was succeeded in his titles by his eldest son, John Vesey.