This paper lays out a definition of 'unpolitics' and makes an attempt to unpack the relationship with populism. Unpolitics is used as a concept to describe the appeal and behaviour of some political actors based on transgressive, conflictual and polarising elements. The argument is made that some populist actors draw on unpolitics but that not all populist actors do. And that some non-populist actors also display unpolitics. The paper is a conceptual contribution but draws on a range of cases from Europe, the US and Latin America, and aims to produce a workable definition and conceptualisation that can be empirically applied to the study of political actors and political parties.