Bishop Thomas Hussey (1746 – 11 July 1803) was a diplomat, chaplain and Bishop of the Roman Catholic Diocese of Waterford and Lismore from 1797 until his death in 1803. He is best known for taking part in talks with Richard Cumberland in a failed attempt to agree a peace treaty between Spain and Britain during the American War of Independence.
Hussey was born at Ballybogan, County Meath in 1746. Due to the restrictions of the Penal Laws, Hussey went to the Irish College at Salamanca for his religious training, and joined the Trappists upon completion of his studies.
The Pope ordered Hussey to take Holy Orders and take a position in the court of the king of Spain. In around 1767 he was appointed as chaplain to the Spanish embassy in London. In 1793-96, shortly after the Roman Catholic Relief Act 1791 repealed some of the laws affecting Catholic worship, a chapel, St James's, Spanish Place, was built to designs by Joseph Bonomi.
Dr Hussey became Spain's diplomatic contact with England when the Spanish ambassador left London because Spain took sides against England during the American War of Independence. Following discussions with the government of Lord North, Hussey was sent to Madrid to discuss Spain's withdrawal from the American cause. Upon his return to Madrid, he attracted the notice of English Catholics in exile, who appealed to the Pope to involve Hussey in the advancement of the Catholic cause in Ireland.