The rise of non-cigarette, alternative tobacco product (ATP) use among adolescents may be due to an increase in retail availability of ATPs. This is the first study to examine the relationship of tobacco retailer density and proximity to any ATP use, assess many ATPs simultaneously, and assess this relationship longitudinally. We examine whether the proximity and density of stores near students’ home is associated with a higher likelihood of initiating ATP use over time including e-cigarettes, small and large cigars, chewing or dipping tobacco or moist snuff, tobacco pipes, and hookah. This geospatial analysis of a multilevel, longitudinal data set linked survey data from 728 adolescents (ages 13-19) nested in 191 neighborhoods nested in 10 California high schools with location data for tobacco retailers from a state licensing list. At the individual level, proximity was measured as roadway distance from home to the nearest tobacco retailer. At the census tract level, tobacco retailer density measured tobacco retailers per square mile. Other tract-level and school-level covariates were obtained from the American Community Survey and the California Department of Education. To account for the fact that students who lived in the same census tracts attended different high schools, cross-classified multilevel logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for proximity to a tobacco retailer and tract density (at baseline) with ATP initiation at follow-up. The sample was predominantly female (63.5%) and was racially and ethnically diverse. Approximately one-third of participants (32.5%) reported ever ATP use at Wave 1 and 106 (14.5%) initiated ATP use within one year (Wave 2). The mean number of tobacco retailers per square mile within a tract was 5.66 (SD=6.3) and the average distance from each participant’s residence to the nearest tobacco retailer was 0.61 miles (SD=0.4). In fully adjusted two-level multilevel models (MLM) adjusting for demographic, socioeconomic, and behavioral factors, higher odds of initiating ATP use were associated with living in tracts with higher retail density (OR=1.32, 95% CI= 1.21, 3.81) in the neighborhood-only model and 1.06 (1.03, 1.92) in the school-only model. After adjusting for covariates, greater tobacco retailer density was still associated with higher odds of ATP initiation (AOR=1.22, 95% CI=1.07, 2.12). Neighborhood-level and school-level variations were 4% and 3%, respectively. Only retail density, not proximity, was related to ATP initiation. Our findings show that tobacco retailers clustered around students’ home neighborhood may be an influence on adolescents’ ATP use. These findings suggest the importance of regulating the tobacco retail environment, in order to reduce the marketing and accessibility of ATPs, which can thereby reduce the uptake of ATPs among youth. Moreover, these findings suggest the importance regulations focused on adolescents’ school environment are expanded to also include regulations of the tobacco retail environment in adolescents’ residential neighborhoods. Policy efforts to reduce adolescent ATP use should limit and reduce the density of tobacco retailers.