An emerging body of research shows Tier 1 Positive Behavioral Interventions and Supports (PBIS) can be successfully implemented in high schools to improve school climate and graduation rates and reduce problem behaviors. However, high schools are often hesitant to adopt PBIS because of contextual barriers such as school size, organizational culture, and student developmental level. Resistance to high school implementation is also related to teachers perceiving PBIS as less socially valid for high school students. Although previous systematic reviews of Tier 1 have examined implementation and effects, none have exclusively focused on the unique contextual needs related to high school implementation. In this review, we synthesized 16 published research studies conducted at the high school level, described how authors addressed the unique challenges of implementing PBIS in high schools, reported findings related to academic and behavioral outcomes, and made recommendations for future research and practice based on our findings.