The study found that within a school’s district, the level of economic disadvantage, residential mobility, and violent crime were not significantly associated with students bringing weapons to school. Regarding the school factors, this study did not find an association between school structural and climate factors and the likelihood of students bringing weapons to school. Supplemental analyses revealed that after adjusting for only student-level sociodemographic characteristics, the proportion of students feeling unsafe at school was significantly associated with increased student weapon-carrying. Being male, having weak attachment to school and parents, experiencing/witnessing interpersonal victimization, and delinquent peer association were all related to school weapon-possession. The null effects for school community disadvantage, residential mobility, and violent crime being related to student weapon-carrying may be partly due to the use of security measures to suppress student weapon-carrying in such communities. Future research should attempt to control for the nonrandom use of school security devices. The study sample consisted of 10,308 students attending 55 high schools serving students in grades 8 through 12. The dependent variable was carrying a weapon (gun, knife, or club) to school at least once during the prior 30 days. Independent variables pertained to community characteristics, school characteristics, and student characteristics. 3 tables, 1 figure, appended survey items, 16 notes, and 91 references