Much like his candidacy, Donald Trump’s presidency has been described as populist par excellence and as fundamentally breaking with the liberal internationalist tradition of American foreign policy. Despite a growing interest in populism and the role it has played in shaping Donald Trump’s appeal to the public at election time in 2016, we lack an understanding of how populist rhetoric after his electoral victory shaped his approach to foreign policy. This article proposes a study of President Trump’s official campaign communication through rally speeches and Twitter during the 2 months prior to the mid-term election in November 2018 as well as tweets published in the official personal account @realDonaldTrump from September to November 2018. The analysis finds that resurgent Jacksonian populism promoted by the Tea Party shapes President Trump’s approach to foreign policy. Fundamentally anti-elitist, Trump’s populism opposes migration, multilateralism, and is deeply sceptical of the United States’ capacity to support a liberal global order that he perceives as detrimental to the economic interest of the American people. In addition, the analysis finds inconsistencies between his campaign discourse of non-intervention in military conflicts abroad and his foreign policy action.