Psychological sense of community among early adolescents has been investigated using instruments developed for adolescents/adults or ad hoc scales. The aim was to contribute to the validation of a scale of Sense of Community in Early Adolescents (SoC-EA) using a 3-year longitudinal study. Participants were 576 Italian students attending middle schools. Participants filled out a questionnaire 3 times, in the second term of their first, second, and third middle school years. Results provided support for a five-factor model and both bifactor and exploratory structural equation modeling (ESEM) models had excellent fit. The SoC-EA can be scored according to each subscale or a total score. In addition, the SoC-EA demonstrated (a) longitudinal measurement invariance across the middle school years; (b) good internal consistency, test-retest reliability, and test-retest correlation across the 3 years; and (c) adequate construct validity. Findings support the use of the SoC-EA to measure sense of community in early adolescence.