It’ll be a long journey to power, with the next Conservative leader not likely to be crowned until the party’s autumn conference at the start of October.
Before then there will be leadership camapigns and votes by MPs and Conservative members to whittle down the candidates and then declare a winner.
But a number of high-profile politicians have already been installed as favourites to take over the top job from Johnson.
Here are the top 12 most likely new inhabitants of 10 Downing Street, according to the bookmakers.
Ben Wallace 11/4
Former soldier Ben Lobban Wallace is the current Secretary of State for Defence, a role he has held since July 2019. He is an MP for Wyre and Preston North, and has was formerly a Conservative list MSP for North East Scotland from 1999 to 2003.
Rishi Sunak 9/2
Johnson’s former Chancellor is the bookies’ favourite to take over from his former boss, after leading the way with Sajid Javid in the recent spate of Cabinet resignations. Before being Chancellor, Rishi Sunak served as Chief Secretary to the Treasury from 2019 to 2020 and has been MP for Richmond (Yorks) since 2015.
Penny Mordaunt 11/2
Penny Mordaunt has been Minister of State for Trade Policy since 2021. She is MP for Portsmouth North and served in Theresa May's Cabinet as Secretary of State for International Development from 2017-2019 and Secretary of State for Defence in 2019.
Liz Truss 8/1
Liz Truss has served as Foreign Secretary since 2021 and Minister for Women and Equalities since 2019. She has been MP for South West Norfolk since 2010 and has served in various cabinet positions under Prime Ministers David Cameron, Theresa May, and Boris Johnson.
Tom Tugendhat 14/1
Former journalist and PR consultant Tom Tugendhat has served as Chairman of the Foreign Affairs Committee since 2017. He is an officer in the Territorial Army and served in the Iraq War and the Afghanistan War. Tugendhat has been MP for Tonbridge and Malling since 2015.
Sajid Javid 10/1
Until his recent resignation Sajid Javid served as Secretary of State for Health and Social Care from June 2021 to July 2022, having previously served as Home Secretary from 2018 to 2019 and Chancellor of the Exchequer from 2019 to 2020. He has been MP for Bromsgrove since 2010.
Nadhim Zahawi 12/1
Before his recent appointment as Chancellor, Iraqi-born Nadhim Zahawi was Secretary of State for Education from 2021 to 2022 and Parliamentary Under-Secretary of State for COVID-19 Vaccine Deployment from 2020 to 2021. He has been MP for Stratford-on-Avon since 2010.
Jeremy Hunt 14/1
Jeremy Hunt has served as Chair of the Health and Social Care Select Committee since 2020. He has previously been Secretary of State for Culture, Olympics, Media and Sport from 2010 to 2012, Secretary of State for Health and Social Care from 2012 to 2018, and Secretary of State for Foreign and Commonwealth Affairs from 2018 to 2019. He has been MP for South West Surrey since 2005.
Steve Baker 16/1
Former Royal Air Force engineer, consultant and bank worker Steven John Baker served as chair of the European Research Group (ERG) for two spells from 2016-2017 and 2019-2020. In June 2015 he became co-chair of Conservatives for Britain, a campaigning organisation formed of Eurosceptic MPs. he has been MP for Wycombe in Buckinghamshire since 2010.
Dominic Raab 33/1
Dominic Raab is currently Deputy Prime Minister, Secretary of State for Justice and Lord Chancellor, having previously been Brexit Secretary in 2018 and First Secretary of State and Foreign Secretary from 2019 to 2021. He has been MP for Esher and Walton since 2010.
Michael Gove 33/1
Before being sacked by Boris Johnson, Michael Gove was Secretary of State for Levelling Up, Housing and Communities and Minister for Intergovernmental Relations. He has served in various other cabinet positions under Prime Ministers David Cameron, Theresa May and Boris Johnson, and has twice run to become Leader of the Conservative Party in 2016 and 2019. He has served as MP for Surrey Heath since 2005.
Suella Braverman 40/1
The first person to declare her intention to run, barrister Suella Braverman QC has been the Attorney General for England and Wales since 2020 and chaired the European Research Group (ERG) from 19 June 2017 to 9 January 2018. She has been MP for Fareham since 2015.