Johnson will officially assume his role on Wednesday afternoon following Theresa May's final prime minister's questions and before she tenders her resignation to the Queen.
Although Johnson hasn't always seen eye-to-eye with Trump, it's more than likely that they will both get along with one another, should it serve their goals as the leaders of their respective nations.
No sooner had Johnson been confirmed as the next prime minister had Trump tweeted to congratulate him on the victory and hailing the former London mayor as being 'great' for the role.
As you can guess, this rather vanilla tweet from the president hasn't gone down too well with critics of both him and Johnson, who share more than a few characteristics.
Trump wasn't the only member of his family to tweet their congratulations to the new prime minister but not before completely botching the tweet, writing 'United Kingston' rather than United Kingdom.