Thomas Thynn, 2nd Viscount Weymouth (1734–1796), was a British nobleman and politician. He succeeded his father, Thomas Thynn, 1st Viscount Weymouth, in 1751 and became a prominent figure in the House of Lords. He was known for his involvement in various political matters during his lifetime. In addition to his political career, Thynn was also a landowner and held significant estates, including Longleat House in Wiltshire. He was married to Lady Elizabeth Thynn, and they had several children, continuing the Thynn family legacy in British aristocracy.