John Denny Vesey, 1st Baron Knapton (died 1761), was an Anglo-Irish politician and peer.
Vesey was the son of Sir Thomas Vesey, 1st Baronet, and his wife and cousin Mary Muschamp, only surviving daughter and heiress of Denny Muschamp of Horsley, Surrey, and his wife Elizabeth Boyle, daughter of Michael Boyle, Archbishop of Armagh.
In 1727 he was elected to the Irish House of Commons as the Member of Parliament for Newtownards, holding the seat until 1750.
He was succeeded in his titles by his eldest son, Thomas Vesey, who was made Viscount de Vesci in 1776.
His daughter Elizabeth married Edmund Pery, 1st Viscount Pery, and another daughter Anne married Thomas Knox, 1st Viscount Northland.