Several factors may impede ethnoracial minority inclusion in Mindfulness- and Meditation-Based Intervention (MMBI) studies, such as healthcare disparities, historical underrepresentation in clinical research, and a conceptual perspective that emphasizes the universality of Buddhist teachings. This systematic review was performed with the aim of describing MMBI studies with a significant diversity focus, defined as involving minority inclusion in sample composition, cultural adaptations of interventions, and/or planned comparisons of outcomes for different ethnoracial groups. Studies were identified through PsycINFO and MEDLINE databases from 1990 to 2016 in the United States. We reviewed 12,265 citations to include 24 MMBI diversity-focused studies. Aside from Native Alaskans, all other major US ethnoracial minority groups were included in at least one study. Most of the studies (75%) were conducted with child and youth samples; the others included only women. Most (58%) included participants selected for a health or mental health condition, but none required specific diagnoses for study inclusion. The most commonly used MMBI was mindfulness-based stress reduction (29%), and only 12.5% of all studies used a culturally adapted intervention. Only one study reported planned ethnoracial comparisons of treatment outcomes. Cohen’s d effect sizes for single-sample studies ranged from 0.10 to 0.62 and for randomized controlled trials ranged from 0.02 to 0.99. Results from this systematic review highlight the dearth of diversity focus in MMBI research. Future work should include indicators of feasibility, acceptability, and safety; address underrepresentation of ethnoracial minorities, men, and participants with clinically or functionally significant symptoms; and investigate cultural adaptations to optimize treatment effectiveness.