List of prime ministers of the United Kingdom by length of tenure

This is a list of prime ministers of the United Kingdom by length of tenure. This is based on the difference between dates; if counted by the number of calendar days, the figures would be one day greater for each term served.

The term prime minister appeared in the early eighteenth century as an unofficial title for the leader of the government, usually the head of the Treasury.^[1] Jonathan Swift, for example, wrote that in 1713 there had been "those who are now commonly called Prime Minister among us", referring to Sidney Godolphin and Robert Harley, Queen Anne's lord treasurers and chief ministers.^[2] Robert Walpole is regarded as the first prime minister; he became First Lord of the Treasury of Great Britain in 1721. This list includes all prime ministers of the Kingdom of Great Britain, the United Kingdom of Great Britain and Ireland, and the modern-day United Kingdom of Great Britain and Northern Ireland.

Notable lengths

A painting of Walpole in formal attire and a powdered wig

20 years and 314 days: Robert Walpole (1721–1742)
Longest term and longest total tenure

12 years and 126 days: William Ewart Gladstone (1868–1874, 1880–1885, 1886, and 1892–1894)
Most non-consecutive terms

11 years and 208 days: Margaret Thatcher (1979–1990)^[3]
Longest-serving prime minister in the 20th century

49 days: Liz Truss (2022)^[4]
Shortest-serving British prime minister

Of the 56 past prime ministers, nine served more than 10 years while eight served less than a year.^[5] Robert Walpole is the only person to have served as prime minister for more than two decades. Liz Truss is the shortest-serving prime minister, resigning after seven weeks.^[4]^[6]^[7] The previous shortest time served was George Canning, who served for less than four months before dying in office.^[8] Margaret Thatcher, in office for 11 years and 288 days between 1979 and 1990, is the longest serving prime minister in modern history,^[3] and the longest-serving prime minister officially referred to as such.^[9]^[10] William Gladstone is the only person to have served four separate terms.

List of office holders by tenure

In this table, "Terms" is the number of separate periods served as prime minister.

Rank	Prime Minister	Tenure length	Terms	Party	Start	End	Reason for exit	Ref.
1	Sir Robert Walpole	20 years, 314 days	1	Whig	1721	1742	Resigned	^[5]
2	William Pitt the Younger	18 years, 343 days	2	Tory (Pittite)	1783	1801	Resigned	^[5]
2	William Pitt the Younger	18 years, 343 days	2	Tory (Pittite)	1804	1806	Died
3	The Earl of Liverpool	14 years, 305 days	1	Tory (Pittite)	1812	1827	Resigned due to illness	^[11]
4	The Marquess of Salisbury	13 years, 252 days	3	Conservative	1885	1886		^[11]
					1886	1892
					1895	1902	Resigned due to illness
5	William Ewart Gladstone	12 years, 126 days	4	Liberal	1868	1874		^[11]
					1880	1885
					1886	1886
					1892	1894	Resigned
6	Lord North	12 years, 58 days	1	Tory (Northite)	1770	1782	Resigned	^[11]
7	Margaret Thatcher	11 years, 208 days	1	Conservative	1979	1990	Resigned	^[11]
8	Henry Pelham	10 years, 191 days	1	Whig	1743	1754	Died	^[11]
9	Sir Tony Blair	10 years, 56 days	1	Labour	1997	2007	Resigned	^[11]
10	The Viscount Palmerston	9 years, 141 days	2	Whig / Liberal	1855	1858		^[5]
10	The Viscount Palmerston	9 years, 141 days	2	Whig / Liberal	1859	1865	Died
11	H. H. Asquith	8 years, 244 days	1	Liberal	1908	1916	Resigned	^[11]
12	Sir Winston Churchill	8 years, 239 days	2	Conservative	1940	1945	Defeated in election	^[5]
12	Sir Winston Churchill	8 years, 239 days	2	Conservative	1951	1955	Resigned due to illness
13	Harold Wilson	7 years, 279 days	2	Labour	1964	1970	Defeated in election	^[11]
13	Harold Wilson	7 years, 279 days	2	Labour	1974	1976	Resigned
14	The Duke of Newcastle	7 years, 205 days	2	Whig	1754	1756		^[5]
14	The Duke of Newcastle	7 years, 205 days	2	Whig	1757	1762
15	Stanley Baldwin	7 years, 82 days	3	Conservative	1923	1924	Lack of majority after election	^[5]
					1924	1929	Defeated in election
					1935	1937	Resigned
16	Benjamin Disraeli	6 years, 339 days	2	Conservative	1868	1868	Election	^[5]
16	Benjamin Disraeli	6 years, 339 days	2	Conservative	1874	1880	Election
17	Ramsay MacDonald	6 years, 289 days	2	Labour	1924	1924	Defeated in election	^[5]
17	Ramsay MacDonald	6 years, 289 days	2	Labour / National Labour	1929	1935	Resigned due to illness
18	Harold Macmillan	6 years, 281 days	1	Conservative	1957	1963	Resigned due to illness	^[11]
19	The Viscount Melbourne	6 years, 255 days	2	Whig	1834	1834		^[5]
19	The Viscount Melbourne	6 years, 255 days	2	Whig	1835	1841	Defeated in election
20	John Major	6 years, 155 days	1	Conservative	1990	1997	Defeated in election	^[5]
21	Lord John Russell	6 years, 110 days	2	Whig / Liberal	1846	1852	Defeated in election	^[5]
21	Lord John Russell	6 years, 110 days	2	Whig / Liberal	1865	1866	Resigned
22	Clement Attlee	6 years, 92 days	1	Labour	1945	1951	Defeated in election	^[11]
23	David Cameron	6 years, 63 days	1	Conservative	2010	2016	Resigned	^[11]
24	David Lloyd George	5 years, 317 days	1	Liberal	1916	1922	Resigned	^[5]
25	Sir Robert Peel	5 years, 57 days	2	Conservative	1834	1835	Defeated in election	^[11]
25	Sir Robert Peel	5 years, 57 days	2	Conservative	1841	1846	Resigned
26	The Earl of Derby	3 years, 280 days	3	Conservative	1852	1852		^[11]
					1858	1859
					1866	1868	Resigned due to illness
27	Edward Heath	3 years, 259 days	1	Conservative	1970	1974	Defeated in election	^[11]
28	The Earl Grey	3 years, 229 days	1	Whig	1830	1834	Resigned	^[5]
29	Arthur Balfour	3 years, 145 days	1	Conservative	1902	1905	Resigned	^[5]
30	The Duke of Portland	3 years, 82 days	2	Whig / Tory (Pittite)	1783	1783		^[11]
30	The Duke of Portland	3 years, 82 days	2	Whig / Tory (Pittite)	1807	1809	Resigned due to illness
31	Henry Addington	3 years, 54 days	1	Tory (Pittite)	1801	1804	Replaced	^[11]
32	Boris Johnson	3 years, 44 days	1	Conservative	2019	2022	Resigned	^[11]
33	James Callaghan	3 years, 29 days	1	Labour	1976	1979	Defeated in election	^[5]
34	Theresa May	3 years, 11 days	1	Conservative	2016	2019	Resigned	^[11]
35	Neville Chamberlain	2 years, 348 days	1	Conservative	1937	1940	Resigned	^[5]
36	The Duke of Wellington	2 years, 320 days	2	Tory	1828	1830	Replaced	^[5]
36	The Duke of Wellington	2 years, 320 days	2	Tory	1834	1834	Caretaker
37	Gordon Brown	2 years, 318 days	1	Labour	2007	2010	Defeated in election	^[5]
38	Spencer Perceval	2 years, 221 days	1	Tory (Pittite)	1809	1812	Assassinated	^[5]
39	Sir Henry Campbell-Bannerman	2 years, 122 days	1	Liberal	1905	1908	Resigned due to illness	^[5]
40	George Grenville	2 years, 85 days	1	Whig (Grenvillite)	1763	1765	Replaced	^[11]
41	The Earl of Chatham	2 years, 76 days	1	Whig (Chathamite)	1766	1768	Resigned due to illness	^[11]
42	The Earl of Aberdeen	2 years, 42 days	1	Peelite	1852	1855	Resigned	^[5]
43	Sir Anthony Eden	1 year, 279 days	1	Conservative	1955	1957	Resigned due to illness	^[11]
44	Rishi Sunak	1 year, 244 days	1	Conservative	2022		Incumbent	^[11]
45	The Earl of Wilmington	1 year, 119 days	1	Whig	1742	1743	Died	^[11]
46	The Marquess of Rockingham	1 year, 113 days	2	Whig (Rockinghamite)	1765	1766	Resigned	^[5]
46	The Marquess of Rockingham	1 year, 113 days	2	Whig (Rockinghamite)	1782	1782	Died
47	The Earl of Rosebery	1 year, 109 days	1	Liberal	1894	1895	Election	^[11]
48	The Duke of Grafton	1 year, 106 days	1	Whig (Chathamite)	1768	1770	Resigned	^[5]
49	The Lord Grenville	1 year, 42 days	1	Whig	1806	1807	Replaced	^[11]
50	Sir Alec Douglas-Home	363 days	1	Conservative (Scot. Unionist)	1963	1964	Defeated in election	^[11]
51	The Earl of Bute	317 days	1	Tory	1762	1763	Resigned	^[5]
52	The Earl of Shelburne	266 days	1	Whig (Chathamite)	1782	1783	Replaced	^[11]
53	The Duke of Devonshire	225 days	1	Whig	1756	1757	Replaced	^[5]
54	Andrew Bonar Law	211 days	1	Conservative (Scot. Unionist)	1922	1923	Resigned due to illness	^[5]
55	The Viscount Goderich	144 days	1	Tory (Canningite)	1827	1828	Replaced	^[5]
56	George Canning	119 days	1	Tory (Canningite)	1827	1827	Died	^[11]
57	Liz Truss	49 days	1	Conservative	2022	2022	Resigned	^[4]^[11]