Previous research suggests media attention may increase support for populist right-wing parties, but extant evidence is mostly limited to proportional representation systems in which such an effect would be most likely. At the same time, in the United Kingdom’s first-past-the-post system, an ongoing political and regulatory debate revolves around whether the media give disproportionate coverage to the populist right-wing UK Independence Party (UKIP). This study uses a mixed-methods research design to investigate the causal dynamics of UKIP support and media coverage as an especially valuable case. Vector autoregression, using monthly, aggregate time-series data from January 2004 to April 2017, provides new evidence consistent with a model in which media coverage drives party support, but not vice versa. The article identifies key periods in which stagnating or declining support for UKIP is followed by increases in media coverage and subsequent increases in public support. The findings show that media coverage may drive public support for right-wing populist parties in a substantively non-trivial fashion that is irreducible to previous levels of public support, even in a national institutional environment least supportive of such an effect. The findings have implications for political debates in the UK and potentially other liberal democracies.