Johnson first attended the European School in Uccle, before attending The Hall School in Hampstead, London, Ashdown House School in East Sussex, and then Eton College. In 1991, he went to Balliol College, Oxford, to read Modern History. He was a Scholar at Balliol, edited Isis, the Oxford University student magazine, and was awarded a First Class degree in both Honour Moderations (June 1992) and Finals (Honour School, June 1994).

After graduating from the Université libre de Bruxelles, in 1995 Johnson joined Deutsche Bank as an investment banker.

In 1997, he switched career paths and joined the Financial Times. After a sabbatical in 1999/2000 during which he gained an MBA from INSEAD, he returned to become Paris correspondent (2001–05), and then as South Asia bureau chief based in New Delhi (2005–08). On return to London he became an associate editor of the Financial Times and head of the Lex Column, one of the most influential positions in British financial journalism.

Johnson’s books include the co-authored The Man Who Tried To Buy the World (Penguin, 2003), about the French businessman Jean-Marie Messier. This was serialised in The Guardian and published in France as Une faillite française by Albin Michel in 2002. He co-edited, with Dr Rajiv Kumar (Secretary General, Federation of Indian Chambers of Commerce and Industry) Reconnecting Britain and India: Ideas for an Enhanced Partnership (Academic Foundation 2011).

In 2009, he was selected as the Conservative parliamentary candidate for the safe seat of Orpington in the London Borough of Bromley from a shortlist of six contenders. At the 2010 general election, he retained the seat for the Conservatives, tripling the majority of his predecessor John Horam to over 17,000. His majority increased again in the general election of 2015, to 19,979.

Previous ‘Heads of Lex’ include Nigel Lawson, former Chancellor of the Exchequer, Martin Taylor, former chief executive of Barclays Bank, and Richard Lambert, director-general of the Confederation of British Industry. Johnson left the Lex column in April 2010. He received awards for his journalism from a range of organisations, including the Foreign Press Association, the Society of Publishers in Asia and The Indian Express’s Excellence in Journalism Awards.

On 25 April 2013, he was appointed Head of the Number 10 Policy Unit by David Cameron to help develop the 2015 Conservative manifesto.

On 11 May 2015, it was announced that Johnson had been appointed Minister for Universities and Science at the Department for Business, Innovation and Skills (BIS). Writing about Johnson’s appointment for Times Higher Education, John Morgan said: “Mr Johnson’s reputation as a pro-European is likely to please vice-chancellors, many of whom are concerned by the Tories’ pledge to hold an in-out referendum on EU membership by 2017. Universities UK pointed out that British higher education institutions benefit from around £1.2 billion in European research funding each year.”

He increased the Conservative share of the vote in the constituency by 5.5% points to 62.9% at the general election in June 2017, although his majority declined to 19,453.

On 9 January 2018, Johnson left his role as Minister for Universities and accepted a new position as Minister of Transport and Minister for London.

On 9 November 2018, Johnson resigned his position, citing disillusionment with the government’s Brexit strategy and called for a fresh vote on Brexit with an option to remain. Johnson argued that Britain was “on the brink of the greatest crisis” since World War Two and claimed that what was on offer was not “anything like what was promised”.

Johnson called on his Conservative Party MPs to vote down Theresa May’s Brexit deal on 11 December 2018, stating that it was ‘half baked’ and the ‘worst of both worlds’. Johnson resigned as a minister in December 2018 because he wanted to be free to endorse a proposed referendum on the Brexit withdrawal agreement.

On 24 July 2019, it was announced that Jo Johnson was appointed Minister of State for Universities, Science, Research and Innovation – this position would mean he would be attending the meetings of the cabinet. He was appointed to the privy council the next day. On 5 September, Johnson resigned as a Minister and announced he would stand down as MP, describing his position as “torn between family and national interest”. He stood down at the next general election rather than resigning, therefore minimising any potential political embarrassment for his brother, the prime minister. A Downing Street spokesman said: “The prime minister would like to thank Jo Johnson for his service… The constituents of Orpington could not have asked for a better representative.”

On 31 July 2020, the announcement was made of Johnson’s elevation to the House of Lords as part of the 2019 Dissolution Honours. He was created Baron Johnson of Marylebone, of Marylebone in the City of Westminster on 12 October.