A brief 15-item version of the California School Climate Scale (Brief-CSCS) is presented to fill a need for a measure that could be used for periodic monitoring of school personnel's general perception of the climate of their school campus. From a sample of 81,261 California school personnel, random subsamples of 2,400 teachers and 2,400 administrators were used in the analyses. Confirmatory factor analyses supported a model in which general school climate was a second-order latent factor composed of 2 first-order latent traits, organizational supports and relational supports. Measurement invariance of factor loadings for teachers and administrators was found. Additional analyses revealed that administrators held more positive perceptions of school climate than teachers, with this difference increasing from primary through high school. The implications for these findings for educational research and policy reform are outlined.