Few studies have considered the potential role of the built environment in increasing adolescent substance use. The current study explored the relationship between alcohol outlets, a potential malleable component of the neighborhood environment, and adolescent behavioral outcomes. Specifically, we investigated the relationship between alcohol outlet density, perceived alcohol, tobacco, and marijuana availability (ATOD), perception of substance use as a problem at the school, and self-reported ATOD use. Data come from Maryland Safe and Supportive Schools (MDS3) Initiative, a statewide project focused on measuring and improving school climate. The sample includes 25,308 adolescents from 58 high schools (9th–12th grade) across 12 counties. Multi-level path models indicated a positive relationship between the count of alcohol outlets and perceived availability of ATOD among girls but not boys. Perceived availability was associated with increased ATOD use at both the individual- and school-level, as well as other students’ ATOD use. Findings provide support for the potential role of the built environment in adolescent risk for substance use, particularly among girls.