| Post: | First Lord of the Treasury |
| Flag: | Flag of the United Kingdom.svg |
| Flagcaption: | Flag of the United Kingdom |
| Insignia: | Royal Coat of Arms of the United Kingdom (HM Government) (2022).svg |
| Insigniacaption: | Royal Arms of His Majesty's Government |
| Incumbent: | Sir Keir Starmer |
| Incumbentsince: | 5 July 2024 |
| Residence: | 10 Downing Street |
| Seat: | Westminster |
| Appointer: | The King |
| Termlength: | At His Majesty's pleasure |
| Deputy: | Second Lord of the Treasury |
The First Lord of the Treasury is the head of the Lords Commissioners of the Treasury exercising the ancient office of Lord High Treasurer in the United Kingdom. Constitutional convention holds that the office of First Lord is held by the Prime Minister. The office is not the United Kingdom's finance minister; this role is instead held by the Chancellor of the Exchequer, who is the second lord of the Treasury.
As of the beginning of the 17th century, the running of the Treasury was frequently entrusted to a commission, rather than to a single individual. Since 1714, it has permanently been in commission. The commissioners have always since that date been referred to as Lords Commissioners of the Treasury, and adopted ordinal numbers to describe their seniority. Eventually in the middle of the same century, the first lord of the Treasury came to be seen as the natural head of the overall ministry running the country, and, as of the time of Robert Walpole (Whig), began to be known, unofficially, as the prime minister.
The term prime minister was initially, but decreasingly, used as a term of derogation; it was first used officially in a royal warrant only in 1905. William Pitt the Younger said the prime minister "ought to be the person at the head of the finances"—though Pitt also served as chancellor of the exchequer for the entirety of his time as prime minister, so his linkage of the finance portfolio to the premiership was wider than merely proposing the occupation of the first lordship by the prime minister.
Prior to 1841 the first lord of the Treasury also held the office of chancellor of the exchequer unless he was a peer and thus barred from that office; in this case, the second lord of the Treasury usually served as chancellor. Since 1841, the chancellor has always been second lord of the Treasury when he was not also prime minister. By convention, the other Lords Commissioners of the Treasury are also Government Whips in the House of Commons.
See main article: 10 Downing Street. 10 Downing Street is the official residence of the first lord of the Treasury, not the office of prime minister. Chequers, a country house in Buckinghamshire, is the official country residence of the prime minister, used as a weekend and holiday home, although the residence has also been used by other senior members of government.
Much of this list overlaps with the list of prime ministers of the United Kingdom, but there are some notable differences, principally concerning Lord Salisbury, who was prime minister but not first lord in 1885–86, 1887–92 and 1895–1902. Those first lords who were simultaneously prime minister are indicated in bold; those who were considered prime minister only during part of their term are indicated in bold italic.
| Name | Entered office | Left office | Party | ||
|---|---|---|---|---|---|
| The Earl of Halifax | 13 October 1714 | 19 May 1715 | Whig | ||
| The Earl of Carlisle | 23 May 1715 | 10 October 1715 | Whig | ||
| Robert Walpole | 10 October 1715 | 12 April 1717 | Whig | ||
| The Earl Stanhope | 12 April 1717 | 21 March 1718 | Whig | ||
| The Earl of Sunderland | 21 March 1718 | 3 April 1721 | Whig | ||
| Sir Robert Walpole | 3 April 1721 | 11 February 1742 | Whig | ||
| The Earl of Wilmington | 16 February 1742 | 2 July 1743 | Whig | ||
| Henry Pelham | 27 August 1743 | 10 February 1746 | Whig | ||
| The Earl of Bath | 10 February 1746 | 12 February 1746 | Whig | ||
| Henry Pelham | 12 February 1746 | 6 March 1754 | Whig | ||
| The Duke of Newcastle | 16 March 1754 | 16 November 1756 | Whig | ||
| The Duke of Devonshire | 16 November 1756 | 8 June 1757 | Whig | ||
| The Earl Waldegrave | 8 June 1757 | 12 June 1757 | Whig | ||
| The Duke of Devonshire | 12 June 1757 | 25 June 1757 | Whig | ||
| The Duke of Newcastle | 2 July 1757 | 26 May 1762 | Whig | ||
| The Earl of Bute | 26 May 1762 | 16 April 1763 | Tory | ||
| George Grenville | 16 April 1763 | 13 July 1765 | Whig | ||
| The Marquess of Rockingham | 13 July 1765 | 30 July 1766 | Whig | ||
| The Duke of Grafton | 30 July 1766 | 28 January 1770 | Whig | ||
| Lord North | 28 January 1770 | 22 March 1782 | Tory | ||
| The Marquess of Rockingham | 27 March 1782 | 1 July 1782 | Whig | ||
| The Earl of Shelburne | 4 July 1782 | 2 April 1783 | Whig | ||
| The Duke of Portland | 2 April 1783 | 19 December 1783 | Whig | ||
| William Pitt the Younger | 19 December 1783 | 14 March 1801 | Tory | ||
| Henry Addington | 17 March 1801 | 10 May 1804 | Tory | ||
| William Pitt the Younger | 10 May 1804 | 23 January 1806 | Tory | ||
| The Lord Grenville | 11 February 1806 | 31 March 1807 | Whig | ||
| The Duke of Portland | 31 March 1807 | 4 October 1809 | Whig | ||
| Spencer Perceval | 4 October 1809 | 11 May 1812 | Tory | ||
| The Earl of Liverpool | 9 June 1812 | 10 April 1827 | Tory | ||
| George Canning | 10 April 1827 | 8 August 1827 | Tory | ||
| The Viscount Goderich | 31 August 1827 | 22 January 1828 | Tory | ||
| The Duke of Wellington | 22 January 1828 | 22 November 1830 | Tory | ||
| The Earl Grey | 22 November 1830 | 16 July 1834 | Whig | ||
| The Viscount Melbourne | 16 July 1834 | 14 November 1834 | Whig | ||
| The Duke of Wellington | 14 November 1834 | 10 December 1834 | Tory | ||
| Sir Robert Peel | 10 December 1834 | 8 April 1835 | Tory | ||
| The Viscount Melbourne | 18 April 1835 | 30 August 1841 | Whig | ||
| Sir Robert Peel | 30 August 1841 | 29 June 1846 | Conservative | ||
| Lord John Russell | 30 June 1846 | 23 February 1852 | Whig | ||
| The Earl of Derby | 23 February 1852 | 19 December 1852 | Conservative | ||
| The Earl of Aberdeen | 19 December 1852 | 6 February 1855 | Peelite | ||
| The Viscount Palmerston | 6 February 1855 | 20 February 1858 | Liberal | ||
| The Earl of Derby | 20 February 1858 | 12 June 1859 | Conservative | ||
| The Viscount Palmerston | 12 June 1859 | 18 October 1865 | Liberal | ||
| The Earl Russell | 29 October 1865 | 28 June 1866 | Liberal | ||
| The Earl of Derby | 28 June 1866 | 27 February 1868 | Conservative | ||
| Benjamin Disraeli | 27 February 1868 | 3 December 1868 | Conservative | ||
| William Ewart Gladstone | 3 December 1868 | 20 February 1874 | Liberal | ||
| Benjamin Disraeli | 20 February 1874 | 23 April 1880 | Conservative | ||
| William Ewart Gladstone | 23 April 1880 | 23 June 1885 | Liberal | ||
| The Earl of Iddesleigh | 29 June 1885 | 1 February 1886 | Conservative | ||
| William Ewart Gladstone | 1 February 1886 | 25 July 1886 | Liberal | ||
| The Marquess of Salisbury | 3 August 1886 | 14 January 1887 | Conservative | ||
| William Henry Smith | 14 January 1887 | 6 October 1891 | Conservative | ||
| Arthur Balfour | 6 October 1891 | 15 August 1892 | Conservative | ||
| William Ewart Gladstone | 15 August 1892 | 5 March 1894 | Liberal | ||
| The Earl of Rosebery | 5 March 1894 | 25 June 1895 | Liberal | ||
| Arthur Balfour | 25 June 1895 | 5 December 1905 | Conservative | ||
| Henry Campbell-Bannerman | 5 December 1905 | 3 April 1908 | Liberal | ||
| H. H. Asquith | 8 April 1908 | 5 December 1916 | Liberal | ||
| David Lloyd George | 6 December 1916 | 19 October 1922 | Liberal | ||