Background: Evidence show that school connectedness is important to youth wellness. However, considerable inconsistency in the concepts and measures of school connectedness exists across studies. In addition, many measures do not capture the multifaceted dimensions of the school connectedness construct. This study examined the psychometric properties of a school connectedness scale that aimed to measure comprehensively the key constructs of school connectedness. Methods: The scale was developed with teachers and tested with an ethnically diverse sample of 717 high school students enrolled in a school connectedness course using confirmatory factor analysis. Results: Confirmatory factor analyses demonstrated the association of the 15 items with the 5 factors identified in the literature-school involvement, academic motivation, school attachment, teacher support, and peer relations (?[superscript 2] = 439.99, df = 83, p < 0.0001, Comparative Fit Index = 0.991, Tucker-Lewis index = 0.988, root mean square error of approximation = 0.077). Cronbach coefficient alphas for the factors ranged from 0.73 to 0.93. Conclusions: Although further tests need to be conducted to assess its validity and reliability, this newly developed scale may provide researchers a tool to measure comprehensively school connectedness for program evaluation.