Thomas Windsor, 1st Viscount Windsor

Lieutenant-General Thomas Windsor, 1st Viscount Windsor (8 June 1738), styled The Honourable Thomas Windsor until 1699, was a British Army officer, landowner and Tory politician who sat in the English and British House of Commons between 1685 and 1712. He was then elevated to the British House of Lords as one of Harley's Dozen.

Life Windsor was the second son of Thomas Hickman-Windsor, 1st Earl of Plymouth, by his second wife Ursula Widdrington, daughter and co-heiress of Sir Thomas Widdrington, Lord Chief Baron of the Exchequer, and Frances Fairfax.

He was made a Page of Honour to James II in 1685 (a post he held until the king was deposed in 1688) and a few months later was returned to Parliament for Droitwich, despite being only around sixteen at the time. Lord Willoughby de Eresby wanted both him and Peter Legh (died 1744) expelled as minors. Windsor took no part in the proceedings of Parliament and was not re-elected in 1687. This being an Irish peerage he was still eligible for election to the English House of Commons, and in 1705 he was once again returned to Parliament for Bramber, a seat he held until 1708. Between 1708 and 1712 he represented Monmouthshire. The latter year he was created an English peer as Baron Mountjoy, in the Isle of Wight, as one of twelve peers created to secure a Tory majority in the House of Lords.

They had six children: two sons and at least four daughters: Hon.Thomas Philip (baptised 6.2.1706 St.Luke's, Chelsea) Herbert Windsor, 2nd Viscount Windsor (1707–1758) ⚭ 1735 Alice Clavering Hon. Ursula Windsor ⚭ 1736 John Wadman Hon. Charlotte Windsor ⚭ 1736 John Kent Hon. Catharine Windsor (1716–1742) ⚭ Mattheus Lestevenon (1715–1797), a daughter who died at a young age

Charlotte died in November 1733. Lord Windsor died in June 1738 and was succeeded in his titles by his son, Herbert.

He inherited the Lower Avon Navigation from his father, who had acquired the rights to it from the future King James II of England.