People’s proclivity for favoring their ingroups over outgroups has negative consequences for individuals, groups, and societies. Social psychologists have explored a variety of techniques to reduce these intergroup biases. Emerging research suggests that mindfulness may be effective for this purpose. Mindfulness is defined as present-moment attention and awareness with an accepting attitude, and it is often cultivated through meditation. Our systematic review of the mindfulness-intergroup literature suggests that, across the heterogeneity of paradigms, mindfulness attenuates intergroup bias. Supporting this supposition, for all studies in the current review, regardless of operationalization of mindfulness (i.e., mindfulness-based intervention, brief mindfulness induction, expert meditators, dispositional mindfulness), the overall effect size was g = +.29 ( k-number of studies = 36; 95% CI [0.20, 0.39]; Z = 5.94, p < .0001), suggesting a small but significant effect of mindfulness on improved levels of intergroup bias. In the current work, we review the eligible studies and their findings in detail and conclude by discussing critical issues and implications for future research.