In the past decade, policymakers have increasingly begun to consider School-Based Health Centers (full-service health clinics located in school buildings) as potential means of addressing the worsening adolescent mental health crisis. However, there is little causal evidence on the impacts of these health centers on mental health and student behavior. This paper looks at the effect of access to School-Based Health Centers on suspensions and dropouts, two metrics that may be strong proxies for adolescent mental health status. First, using data from a statewide survey on school climate and socioemotional well-being I provide descriptive evidence that worse reported mental health and school climate are positively correlated with higher suspension rates but not necessarily with higher dropout rates. Next, I look at the effect of access to a school-based health center using a difference-in-differences analysis that leverages the timing of health center openings in California and a propensity-score matched control group. The opening of a new school-based health center decreases school-level suspension rates by around 1.1 percentage points (27% of the baseline suspension rate) within 3 years of the opening when compared to matched schools. A heterogeneity analysis reveals that these effects are driven by decreases in suspensions from “disruptive behavior", rather than weapon possession, violence, or drug use. I find no effect on dropout rates, suggesting that the decline in suspensions is unlikely to be caused by the crowd-out of delinquent behavior by an increase in dropouts. These results suggest that school-based health centers warrant further consideration as an effective means of addressing adolescent mental health.