The aims of the study were (a) to establish norms for the Swedish child self-report and caregiver rating versions of the Junior and Temperament Character Inventory (JTCI) among young adolescents, (b) to investigate its psychometric properties, and (c) to investigate congruence between children’s self-reports and caregivers’ ratings of a child’s personality. The sample was a general population of 1,046 children ages 12–14 years and 654 caregivers. The JTCI was found to be reliable on all dimensions except Persistence in the child self-report version. Caregivers rated their own children’s personalities as more mature than did the children themselves. Caregivers especially overestimated their daughters’ self-reported capabilities for self-acceptance and self-efficacy and might have underestimated their daughters’ need for emotional support. This highlights the importance of including the child’s self-report on personality in both research and clinical assessments. The results also support the importance of age- and gender-separated norms.