This study aimed to validate a Religious Collective Self-Esteem Scale (RCSES) that assesses children’s evaluations and judgments about their belonging to a religious group. The RCSES includes 3 subscales: Private Religious Self-Esteem (PrRSE), Public Religious Self-Esteem (PuRSE), and Importance to Religious Identity (RI). Data were gathered from students in 39 primary schools (9 Reformed Protestant, 9 Islamic, 3 Hindu and 18 public schools) across five regions in the Netherlands. Students were asked to complete an anonymous questionnaire containing measures of variables of interest. Subjects were 1,437 6th graders (Mage = 11.72, SD = 0.61; 51.7% girls. 680 Students identified themselves as Muslim (47.3%), 442 (30.8%) as Christian, 278 (19.3%) as Hindu, and 37 (2.6%) children had another religion. Results indicated sufficient internal consistency of RCSES (α = .80), PrRSE (α = .77), PuRSE (α = .73), and RI (α = .60), moderate to high correlations between the subscales and moderate to large test–retest reliability across 1 year (r = .57). Three-factor model fitted the best. Overall, findings support partial measurement and structural invariance across religious groups. Convergent validity was supported by small to moderate correlations with other scales (Individual Self-Esteem Scale, r = .29; Private Ethnic Self-Esteem Scale (PESES), r = .40). Divergent validity was supported by positive small significant correlations with school well-being (r = .18) and social school motivation (r = .19). RCSES and its subscales significantly predicted, over and above PESES, school well-being and school motivation scores. Findings support the reliability and validity of the RCSES for assessing religious collective self-esteem. (PsycINFO Database Record (c) 2017 APA, all rights reserved)