Although evidence suggests significant and positive relationships between School-Wide Positive Behavioral Interventions and Supports (SWPBIS) implementation and student outcomes, research is still needed to review and consolidate this existing literature base. The current study synthesized findings from 55 cases in order to better understand the (a) general quantity, quality, and types of SWPBIS research being conducted, and (b) overall magnitude of these relationships across studies. The majority of cases were single descriptive studies, included PBIS implementation data, and studied diverse elementary or multigrade populations within the United States. Of the cases that performed statistical analyses, the majority reported unanimously positive or predominately positive findings, and these findings were notably more positive for behavioral outcomes than for academic outcomes. Limitations and implications for future research and practice are discussed.