Objectives: To describe the development of an original scale that measures perceived school climate for active travel in fourth- and fifth-grade girls and boys. Methods: The data were analyzed using confirmatory factor analysis (CFA) to provide evidence of factorial validity, factorial invariance, and construct validity. Results: The CFA supported the fit of a 3-factor (encouragement, praise, and importance) correlated model for the school climate for active travel measure. This hierarchical model was invariant between sex and across a 7-month time period, and initial evidence for construct validity was provided. Conclusions: School climate for active travel is a measurable construct, and preliminary evidence suggests relationships with more support for active travel from friends and family.