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

20 years and 315 days: Robert Walpole (1721–1742)
Longest term and longest total tenure

12 years and 130 days: William Ewart Gladstone (1868–1874, 1880–1885, 1886, and 1892–1894)
Most non-consecutive terms

11 years and 209 days: Margaret Thatcher (1979–1990)^[3]
Longest-serving prime minister in the 20th century

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

Of the 57 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 (then Great Britain) 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 208 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

•   Conservative (20)
•   Whig (16)
•   Tory (10)
•   Labour (7)
•   Liberal (7)
•   Scottish Unionists (2)
•   National Labour (1)
•   Peelite (1)

Rank		Portrait	Prime Minister	Party	Start	End	Tenure length (term)	Tenure length (total)	Reason for exit	Ref.
1			Sir Robert Walpole	Whig	3 April 1721	11 February 1742	20 years, 315 days		Resigned	[5]
2			William Pitt the Younger	Tory (Pittite)	19 December 1783	14 March 1801	17 years, 86 days	18 years, 345 days	Resigned
					10 May 1804	23 January 1806	1 year, 259 days		Died
3			The Earl of Liverpool	Tory (Pittite)	8 June 1812	9 April 1827	14 years, 306 days		Resigned due to illness	[11]
4			The Marquess of Salisbury	Conservative	23 June 1885	28 January 1886	220 days	13 years, 255 days	Resigned
					25 July 1886	11 August 1892	6 years, 18 days		Defeated in election
					25 June 1895	11 July 1902	7 years, 17 days		Resigned due to illness
5			William Ewart Gladstone	Liberal	3 December 1868	17 February 1874	5 years, 77 days	12 years, 130 days	Defeated in election
					23 April 1880	9 June 1885	5 years, 48 days		Defeated in election
					1 February 1886	20 July 1886	170 days		Resigned
					15 August 1892	2 March 1894	1 year, 200 days		Resigned
6			Lord North	Tory (Northite)	28 January 1770	27 March 1782	12 years, 59 days		Resigned
7			Margaret Thatcher	Conservative	4 May 1979	28 November 1990	11 years, 209 days		Resigned
8			Henry Pelham	Whig	27 August 1743	6 March 1754	10 years, 192 days		Died
9			Tony Blair	Labour	2 May 1997	27 June 2007	10 years, 57 days		Resigned
10			The Viscount Palmerston	Whig	6 February 1855	19 February 1858	3 years, 14 days	9 years, 143 days	Resigned	[5]
				Liberal	12 June 1859	18 October 1865	6 years, 129 days		Died
11			H. H. Asquith	Liberal	8 April 1908	5 December 1916	8 years, 243 days		Resigned	[11]
12			Sir Winston Churchill	Conservative	10 May 1940	26 July 1945	5 years, 78 days	8 years, 240 days	Defeated in election	[5]
					26 October 1951	5 April 1955	3 years, 162 days		Resigned due to illness
13			Harold Wilson	Labour	16 October 1964	19 June 1970	5 years, 247 days	7 years, 280 days	Defeated in election	[11]
					4 March 1974	5 April 1976	2 years, 33 days		Resigned
14			The Duke of Newcastle	Whig	16 March 1754	11 November 1756	2 years, 241 days	7 years, 207 days	Dismissed	[5]
					29 June 1757	26 May 1762	4 years, 332 days		Dismissed
15			Stanley Baldwin	Conservative	22 May 1923	22 January 1924	246 days	7 years, 85 days	Lack of majority after election
					4 November 1924	4 June 1929	4 years, 213 days		Defeated in election
					7 June 1935	28 May 1937	1 year, 356 days		Resigned
16			Benjamin Disraeli	Conservative	27 February 1868	1 December 1868	279 days	6 years, 341 days	Election
					20 February 1874	21 April 1880	6 years, 62 days		Election
17			Ramsay MacDonald	Labour	22 January 1924	4 November 1924	288 days	6 years, 291 days	Defeated in election
				Labour / National Labour	5 June 1929	7 June 1935	6 years, 3 days		Resigned due to illness
18			Harold Macmillan	Conservative	10 January 1957	18 October 1963	6 years, 282 days		Resigned due to illness	[11]
19			The Viscount Melbourne	Whig	16 July 1834	14 November 1834	122 days	6 years, 257 days	Dismissed	[5]
					18 April 1835	30 August 1841	6 years, 135 days		Defeated in election
20			John Major	Conservative	28 November 1990	2 May 1997	6 years, 156 days		Defeated in election
21			Lord John Russell	Whig	30 June 1846	21 February 1852	5 years, 237 days	6 years, 112 days	Defeated in election
				Liberal	29 October 1865	26 June 1866	241 days		Resigned
22			Clement Attlee	Labour	26 July 1945	26 October 1951	6 years, 93 days		Defeated in election	[11]
23			David Cameron	Conservative	11 May 2010	13 July 2016	6 years, 64 days		Resigned
24			David Lloyd George	Liberal	6 December 1916	19 October 1922	5 years, 318 days		Resigned	[5]
25			Sir Robert Peel	Conservative	10 December 1834	8 April 1835	120 days	5 years, 57 days	Defeated in election	[11]
					30 August 1841	29 June 1846	4 years, 304 days		Resigned
26			The Earl of Derby	Conservative	23 February 1852	17 December 1852	299 days	3 years, 283 days	No confidence vote
					20 February 1858	11 June 1859	1 year, 112 days		No confidence vote
					28 June 1866	25 February 1868	1 year, 243 days		Resigned due to illness
27			Edward Heath	Conservative	19 June 1970	4 March 1974	3 years, 259 days		Defeated in election
28			The Earl Grey	Whig	22 November 1830	9 July 1834	3 years, 230 days		Resigned	[5]
29			Arthur Balfour	Conservative	12 July 1902	4 December 1905	3 years, 146 days		Resigned
30			The Duke of Portland	Whig	2 April 1783	18 December 1783	261 days	3 years, 83 days	Lost a vote in the Lords	[11]
				Tory (Pittite)	31 March 1807	4 October 1809	2 years, 188 days		Resigned due to illness
31			Henry Addington	Tory (Pittite)	17 March 1801	10 May 1804	3 years, 55 days		Replaced
32			Boris Johnson	Conservative	24 July 2019	6 September 2022	3 years, 45 days		Resigned
33			James Callaghan	Labour	5 April 1976	4 May 1979	3 years, 30 days		Defeated in election	[5]
34			Theresa May	Conservative	13 July 2016	24 July 2019	3 years, 12 days		Resigned	[11]
35			Neville Chamberlain	Conservative	28 May 1937	10 May 1940	2 years, 357 days		Resigned	[5]
36			The Duke of Wellington	Tory	22 January 1828	16 November 1830	2 years, 299 days	2 years, 322 days	Replaced
					17 November 1834	9 December 1834	23 days		Caretaker
37			Gordon Brown	Labour	27 June 2007	11 May 2010	2 years, 319 days		Defeated in election
38			Spencer Perceval	Tory (Pittite)	4 October 1809	11 May 1812	2 years, 221 days		Assassinated
39			Sir Henry Campbell-Bannerman	Liberal	5 December 1905	3 April 1908	2 years, 121 days		Resigned due to illness
40			George Grenville	Whig (Grenvillite)	16 April 1763	10 July 1765	2 years, 86 days		Replaced	[11]
41			The Earl of Chatham	Whig (Chathamite)	30 July 1766	14 October 1768	2 years, 77 days		Resigned due to illness
42			The Earl of Aberdeen	Peelite	19 December 1852	30 January 1855	2 years, 43 days		Resigned	[5]
43			Sir Anthony Eden	Conservative	6 April 1955	9 January 1957	1 year, 279 days		Resigned due to illness	[11]
44			Rishi Sunak	Conservative	25 October 2022	5 July 2024	1 year, 255 days		Defeated in election
45			The Earl of Wilmington	Whig	16 February 1742	2 July 1743	1 year, 137 days		Died
46			The Marquess of Rockingham	Whig (Rockinghamite)	13 July 1765	30 July 1766	1 year, 18 days	1 year, 115 days	Resigned	[5]
					27 March 1782	1 July 1782	97 days		Died
47			The Earl of Rosebery	Liberal	5 March 1894	22 June 1895	1 year, 110 days		Election	[11]
48			The Duke of Grafton	Whig (Chathamite)	14 October 1768	28 January 1770	1 year, 107 days		Resigned	[5]
49			Sir Keir Starmer	Labour	5 July 2024	Incumbent	1 year, 45 days[a]
50			The Lord Grenville	Whig	11 February 1806	25 March 1807	1 year, 43 days		Replaced	[11]
51			Sir Alec Douglas-Home	Conservative (Scot. Unionist)	19 October 1963	16 October 1964	364 days		Defeated in election	[11]
52			The Earl of Bute	Tory	26 May 1762	8 April 1763	318 days		Resigned	[5]
53			The Earl of Shelburne	Whig (Chathamite)	4 July 1782	26 March 1783	266 days		Replaced	[11]
54			The Duke of Devonshire	Whig	16 November 1756	29 June 1757	226 days		Replaced	[5]
55			Andrew Bonar Law	Conservative (Scot. Unionist)	23 October 1922	20 May 1923	210 days		Resigned due to illness	[5]
56			The Viscount Goderich	Tory (Canningite)	31 August 1827	8 January 1828	131 days		Replaced
57			George Canning	Tory (Canningite)	12 April 1827	8 August 1827	119 days		Died	[11]
58			Liz Truss	Conservative	6 September 2022	25 October 2022	49 days		Resigned	[4][11]

Disputed

	Portrait	Prime Minister	Party	Start	End	Tenure length	Reason for exit
		The Earl Waldegrave	Whig	8 June 1757	12 June 1757	5 days	Unsupported
		The Earl of Bath	Whig	10 February 1746	12 February 1746	3 days	Unsupported

Notes

1. As of 19 August 2025

See also

• History of the prime minister of the United Kingdom
• List of leaders of the opposition of the United Kingdom by length of tenure
• List of prime ministers of the United Kingdom
• List of prime ministers of the United Kingdom by age
• List of prime ministers of Australia by time in office
• List of prime ministers of Canada by time in office
• List of prime ministers of New Zealand by time in office