The prime minister of the United Kingdom is the principal minister of the government of the British monarchy and the head of the British cabinet.
| Name | Party | Term Began | Term ended |
|---|---|---|---|
| Benjamin Disraeli | Conservative | 27 February 1868 | 1 December 1868 |
| William Ewart Gladstone | Liberal | 3 December 1868 | 17 February 1874 |
| Benjamin Disraeli (again) | Conservative | 20 February 1874 | 21 April 1880 |
| William Ewart Gladstone (again) | Liberal | 23 April 1880 | 9 June 1885 |
| Robert Gascoyne-Cecil | Conservative | 23 June 1885 | 28 January 1886 |
| William Ewart Gladstone (again) | Liberal | 1 February 1886 | 20 July 1886 |
| Robert Gascoyne-Cecil (again) | Conservative | 25 July 1886 | 11 August 1892 |
| William Ewart Gladstone (again) | Liberal | 15 August 1892 | 2 March 1894 |
| Archibald Primrose | Liberal | 5 March 1894 | 22 June 1895 |
| Robert Gascoyne-Cecil (again) | Conservative | 25 June 1895 | 11 July 1902 |
| Arthur Balfour | Conservative | 12 July 1902 | 4 December 1905 |
| Henry Campbell-Bannerman | Liberal | 5 December 1905 | 3 April 1908 |
| H.H. Asquith | Liberal | 8 April 1908 | 5 December 1916 |
| David Lloyd George | Liberal | 6 December 1916 | 19 October 1922 |
| Bonar Law | Conservative | 23 October 1922 | 20 May 1923 |
| Stanley Baldwin | Conservative | 22 May 1923 | 22 January 1924 |
| Ramsay Macdonald | Labour | 22 January 1924 | 4 November 1924 |
| Stanley Baldwin (again) | Conservative | 4 November 1924 | 4 June 1929 |
| Ramsay Macdonald (again) | National Labour | 5 June 1929 | 7 June 1935 |
| Stanley Baldwin (again) | Conservative | 7 June 1935 | 28 May 1937 |
| Neville Chamberlain | Conservative | 28 May 1937 | 10 May 1940 |
| Winston Churchill | Conservative | 10 May 1940 | 26 July 1945 |
| Clement Atlee | Labour | 26 July 1945 | 26 October 1951 |
| Winston Churchill (again) | Conservative | 26 October 1951 | 5 April 1955 |
| Anthony Eden | Conservative | 6 April 1955 | 9 January 1957 |
| Harold Macmillan | Conservative | 10 January 1957 | 18 October 1963 |
| Alec Douglas-Home | Conservative | 18 October 1963 | 16 October 1964 |
| Harold Wilson | Labour | 16 October 1964 | 19 June 1970 |
| Edward Heath | Conservative | 19 June 1970 | 4 March 1974 |
| Harold Wilson (again) | Labour | 4 March 1974 | 5 April 1976 |
| James Callaghan | Labour | 5 April 1976 | 4 May 1979 |
| Margaret Thatcher | Conservative | 4 May 1979 | 28 November 1990 |
| John Major | Conservative | 28 November 1990 | 2 May 1997 |
| Tony Blair | Labour | 2 May 1997 | 27 June 2007 |
| Gordon Brown | Labour | 27 June 2007 | 11 May 2010 |
| David Cameron | Conservative | 11 May 2010 | 13 July 2016 |
| Theresa May | Conservative | 13 July 2016 | 24 July 2019 |
| Boris Johnson | Conservative | 24 July 2019 | 6 September 2022 |
| Liz Truss | Conservative | 6 September 2022 | 25 October 2022 |
| Rishi Sunak | Conservative | 25 October 2022 | Incumbent |