AbstractScholarship on Karl Barth's engagement with so-called ‘personalist philosophy’ has claimed that the following three sources exerted a significant influence on this aspect of Barth's thought: (1) the founders of an interdisciplinary society known as the ‘Patmos Circle’; (2) Barth's fellow dialectical theologians, Emil Brunner and Friedrich Gogarten; (3) Martin Buber, in particular his classic work, I and Thou. In spite of these assessments, however, I argue that Barth's initial stance towards personalism is actually best characterised as one of resistance and criticism. Specifically, I claim here that Barth undertakes a highly critical appropriation of personalism in which the categories of encounter (Begegnung), co-humanity (Mitmenschlichkeit) and the I–Thou relation (Ich–Du-Beziehung) are deeply criticised and recast in an explicitly theological – not philosophical – mould. When Barth does use personalist categories in his own theological anthropology – particularly in the Church Dogmatics, III/2 – he roots his notion of the human being as a ‘being in encounter’ in his christology and trinitarian theology, comprehensively restructuring personalist categories by placing them on a new foundation.