Academics, members of Parliament, the general public and journalists alike have attempted to rank prime ministers of the United Kingdom and prime ministers of Great Britain. Those included below generally consist of only a subset of prime ministers, typically those of the 20th century or those who served after the Second World War.

Generally, Clement Attlee, Winston Churchill, David Lloyd George, Margaret Thatcher and Tony Blair appear toward the top of rankings, while Anthony Eden generally appears at the bottom.

In December 1999 a BBC Radio 4 poll of 20 prominent historians, politicians and commentators for The Westminster Hour produced the verdict that Churchill was the best British prime minister of the 20th century, with Lloyd George in second place and Clement Attlee in third place. As Blair was still in office he was not ranked. The worst prime minister in that survey was judged to be Anthony Eden.^[1]

In 2004, the University of Leeds and Ipsos Mori conducted an online survey of 258 academics who specialised in 20th-century British history and/or politics. There were 139 replies to the survey, a return rate of 54% – by far the most extensive survey done so far.^{[citation needed]} The respondents were asked, among other historical questions, to rate all the 20th-century prime ministers in terms of their success and asking them to assess the key characteristics of successful ones. Respondents were asked to indicate on a scale of 0 to 10 how successful or unsuccessful they considered each prime minister to have been in office (with 0 being highly unsuccessful and 10 highly successful). A mean of the scores was calculated and a league table based on the mean scores.^[2] The five Labour prime ministers were, on average, judged to have been the most successful, with a mean of 6.0 (median of 5.9). The three Liberals averaged 5.8 (median of 6.2) and the twelve Conservatives 4.8 (median of 4.1).

In a 2006 issue of BBC History, historian Francis Beckett ranked the 20th-century prime ministers with points out of five in 2006, based on how well the leaders implemented their policies – not on the policies themselves. Margaret Thatcher and Clement Attlee shared the highest ranking.^[3]

In 2010, the University of Leeds and Woodnewton Associates carried out a survey of 106 academics who specialised in British politics or British history, to rank the performance of all 12 prime ministers who served between 1945 and 2010. Churchill's ranking was thus determined from his second term only.^[4][5]

In October 2016 the University of Leeds, in conjunction with Woodnewton Associates, surveyed 82 academics specialising in post-1945 British history and politics, following the Brexit referendum. Due to the date range, Churchill's oft-lauded war ministry and caretaker ministry were not in contention and he was judged solely on his second premiership.^[6]

In June 2021 the University of Leeds, again with Woodnewton Associates, surveyed 93 academics specialising in British politics and modern British history to rank the performance of post-war prime ministers from Churchill to Theresa May.^[7][8]

The following table collects these surveys, although they are not all comparable.

Key:

•   blue background indicates a rank within the first quartile of its respective ranking
•   green background indicates a rank within the second quartile of its respective ranking
•   yellow background indicates a rank within the third quartile of its respective ranking
•   orange background indicates a rank within the fourth quartile of its respective ranking
•   yellow-green background indicates a median which does not fall into any quartile, used when the total number of figures ranked is not a multiple of four

In 2013, a group of academic staff and students at Royal Holloway, University of London, conducted a postal survey of British members of Parliament, asking them to evaluate the success of post-war British prime ministers. Some 158 MPs replied to the survey, a response rate of 24%. The respondents were 69 Conservatives, 67 Labour MPs, 14 Liberal Democrats and 8 MPs from other parties.^[9]

The survey used the same question employed in the 2004 and 2010 University of Leeds studies: MPs were asked how successful or unsuccessful they considered each prime minister to have been using a 0 to 10 scale, where 0 meant highly unsuccessful and 10 meant highly successful.

Overall, MPs rated Margaret Thatcher as the most successful post-war prime minister, just ahead of Clement Attlee. With the exception of Edward Heath, who was judged more favourably by Labour MPs than by Conservatives, evaluations were split along party lines: Conservative MPs tended to consider Conservative prime ministers to be more successful than did Labour MPs, and Labour MPs generally gave Labour prime ministers higher scores than did Conservative MPs.

In 2023 the survey was redone with 65 correspondences.

Key:

•   blue background indicates a rank within the first quartile of its respective ranking
•   green background indicates a rank within the second quartile of its respective ranking
•   yellow background indicates a rank within the third quartile of its respective ranking
•   orange background indicates a rank within the fourth quartile of its respective ranking
•   yellow-green background indicates a median which does not fall into any quartile, used when the total number of figures ranked is not a multiple of four

Both The Times^[14] and Iain Dale^[15] have specifically ranked all (or almost all) prime ministers of the United Kingdom and prime ministers of Great Britain.

Key:

•   blue background indicates a rank within the first quartile of its respective ranking
•   green background indicates a rank within the second quartile of its respective ranking
•   yellow background indicates a rank within the third quartile of its respective ranking
•   orange background indicates a rank within the fourth quartile of its respective ranking
•   yellow-green background indicates a median which does not fall into any quartile, used when the total number of figures ranked is not a multiple of four

• List of current heads of government in the United Kingdom and dependencies
• 100 Greatest Britons

Other countries

• Historical rankings of prime ministers of Australia
• Historical rankings of prime ministers of Canada
• Historical rankings of chancellors of Germany
• Historical rankings of prime ministers of the Netherlands
• Historical rankings of presidents of the United States