School-Wide Positive Behavior Interventions and Supports (SWPBIS) is a systems approach to supporting the social and emotional needs of all children utilized by more than 21,000 schools across the nation. Data from numerous studies and state projects’ evaluation reports point to the impact of SWPBIS on student outcomes (office discipline referrals [ODRs], in-school suspensions [ISSs], out-of-school suspensions [OSSs]) and the possible relationship between implementation fidelity and those student outcomes. With data from 1,122 Florida schools, this study used a longitudinal design to examine the associations between the total score and 10 subscale scores on the Benchmarks of Quality (BoQ), a validated SWPBIS implementation fidelity measure, and school-level behavioral outcomes: ODRs, ISSs, and OSSs. Results of these analyses found a decreasing trend across all three behavioral outcomes, and schools having higher BoQ total scores realized lower ODRs and had corresponding fewer ISSs and OSSs. Of the 10 subscales, the Classroom was negatively and significantly associated with ODRs and OSSs, whereas the BoQ Data Entry Plan was positively and significantly associated with ODRs at initial status and across time after controlling for school-level characteristics (e.g., size, number of years of implementation). The implications of the findings for SWPBIS assessment and intervention in the classroom are discussed.