James Slack CBE is a British political advisor and journalist who served as Downing Street Director of Communications for Prime Minister Boris Johnson between January and March 2021.

[1] At the Daily Mail, as home affairs editor, Slack was involved in the campaign to stop Gary McKinnon, who has Asperger syndrome, from being extradited to the United States to face charges relating to computer hacking.

[1][2][3] Slack wrote the controversial "Enemies of the People" front-page article on 4 November 2016 which criticised senior judges in England's High Court of Justice who had made a decision the Daily Mail did not agree with.

[9] Following the announcement that the then-Downing Street Director of Communications, Lee Cain, had resigned from government and would leave his post at the end of December 2020 it was confirmed that Slack would assume this position in the new year.

[14] On 13 January 2022, The Daily Telegraph reported on two parties alleged to have been held at 10 Downing Street in April 2021, on the eve of the funeral of Prince Philip, Duke of Edinburgh, when the UK was observing a period of national mourning following the Duke's death the previous week, and as England remained in step two lockdown restrictions, where people were only permitted to meet up outdoors.