This review presents the contributions of anti-foreigner sentiment research, its theoretical and methodological limitations, and potential solutions for its further development. Six different explanations are proposed to account for the distribution of anti-foreigner sentiment within and across countries: economic competition, human capital, cultural affinity, social capital, political values, and the institutional environment. In this review, we argue that much of the extant literature heavily emphasizes variables, rather than causal mechanisms, and exhibits three main methodological limitations: (a) variable selection bias; (b) determining causality; and (c) endogeneity. We propose synthesizing prevailing theoretical perspectives around causal mechanisms and reformulating predictive models to strengthen a promising research program.