Among the protective factors associated with reduced risk for suicide, scientific inquiries into school connectedness are especially important considering that schools are ideally situated to provide interventions reaching the vast majority of youth. Although there is a wealth of research that supports the association between school connectedness and reduced self-report of adolescents having a suicidal thought or making a suicide attempt, inconsistencies in the way studies have measured and operationalized school connectedness limit synthesis across findings. This meta-analytic study investigates the literature exploring associations between school connectedness and suicidal thoughts and behaviors across general and subpopulations (high risk and sexual minority youth) using a random effects model. Eligible studies examined a measure of school connectedness explicitly referred to as "school connectedness" or "connections at school" in relation to suicidal ideation or suicide attempts among youth enrolled in school (Grades 6-12). Multiple metaregression analyses were conducted to explore the influence of school connectedness measurement variation, as well as participant characteristics. Results, including 16 samples, support that higher school connectedness is associated with reduced reports of suicidal thoughts and behaviors across general (odds ratio [OR] = 0.536), high-risk (OR = 0.603), and sexual minority (OR = 0.608) adolescents. Findings are consistent when analyzed separately for suicidal ideation (OR = 0.529) and suicide attempts (OR = 0.589) and remain stable when accounting for measurement variability. Although limited by its cross-sectional nature, findings support recent calls to increase school connectedness and proffer important implications for screening and intervention efforts conducted in schools.