While dislike of opposing parties, i.e., affective polarization, is a defining feature of contemporary politics, research on this topic largely centers on the United States. We introduce an approach that analyzes affective polarization between pairs of parties, bridging the US two-party system and multiparty systems in other democracies. Analyzing survey data from 20 Western democracies since the mid-1990s, we first show that partisans’ dislike of out-parties is increasingly linked to elite policy disagreements on cultural issues, as opposed to economics issues. Second, we argue and empirically demonstrate that governing coalition partners in parliamentary democracies display much warmer feelings towards each other than we would expect based on elite policy (dis)agreements. Third, we show that radical right parties are disliked much more intensely than we would expect based on policy disputes and coalition arrangements. These findings highlight the policy-based and institutional underpinnings of affective polarization.