He was educated by a private tutor and at Christ Church, Oxford. He then carved out a military career, rising from lieutenant in 1757 to general in 1783.
He served from 1760 to 1761 as M.P. for Chipping Wycombe, a pocket borough seat that he obtained without electoral contest. He became the second Earl of Shelburne in 1761.
He distinguished himself early in his career, in the Battle of Minden (1759), becoming a colonel at age 23 and an aide-de-camp to George III.He served as First Lord of the Treasury in 1763, in the ministry of Lord Bute, and as secretary of state for the Southern Department (1766— 1768), in the ministry of William Pitt, the Elder. He held no posts from 1768 until Lord North resigned from office in 1782.
In 1782, Shelburne was appointed secretary of state for home affairs (home secretary) in the ministry of the second Marquess of Rockingham, who died shortly after taking office. The king then (in July 1782) chose Shelburne as prime minister, rather than the Duke of Portland, the new leader of the Rockinghamites. This led to the resignation of Charles James Fox and Lord North, who opposed Shelburne’s ministry. The treaty hammered out between Britain and America under Shelburne’s leadership, guaranteeing American independence, was poorly received in Britain; and lacking personal influence within Parliament, Shelburne was replaced in February 1783 by William Henry Cavendish, the third Duke of Portland.
Shelburne never held high office again. He died shortly afterward, on 7 May 1805. He was survived by his second wife.
From the start he was committed to retaining the powers of the Crown, opposed to party politics as such, and supportive of political reforms that would widen the franchise and admit the middle classes to the electorate. As a result he aligned himself with Lord Bute, the king’s favorite in the early 1760s, and with Henry Fox. These connections won him the enmity of many party or factional groups that emerged in the 1760s and had little real power in Parliament.
Throughout the 1780s and 1790s advocated an unpopular, positive policy toward France. In 1791 he praised the French National Assembly for declaring that the right to make peace or war came from the nation and not the Crown, and urged the British government to follow this example. In 1793 he opposed the war against France and further opposed government measures to curb radicalism in Britain. In 1803, he made his last public speech, in favor of conciliation with France.
His second wife was Lady Louisa Fitzpatrick, daughter of the first Earl of Upper Ossory; he had previously been married to Lady Sophia Carteret, daughter of John, second Earl Granville, in 1765.