Purpose: A comprehensive school physical activity program (CSPAP) is designed to help school-aged youth meet physical activity guidelines as well as develop the knowledge, skills, and dispositions that foster meaningful lifelong physical activity participation. In this study, we employed a "diffusion of innovations theory" perspective to examine the adoption of CSPAPs in relation to physical education teachers' domain-specific innovativeness, educational background, demographics, and perceived school support. Methods: Physical education teachers (N = 407) responded to an electronic survey with validated measures for each of the above-mentioned variables. Results: Latent profile analysis classified teachers into three domain-specific innovativeness levels (high, average, and low). CSPAP-related professional training, knowledge, and perceived school support were found to be significant factors in domain-specific innovativeness and CSPAP adoption. Discussion/Conclusion: This study provides novel evidence to inform professional development initiatives so that they can be tailored to physical education teachers who may be less likely to adopt a CSPAP.