Young people's confidence in their creative abilities, as well as their beliefs about whether these abilities are fixed or malleable, play potentially important roles in educators' efforts to foster creativity. This study explores a multidimensional model of young people's creative self-beliefs that comprises creative self-efficacy, growth-creative mindsets, and fixed-creative mindsets. It operationalizes and tests this model via a new three-factor instrument appropriate for young samples. Drawing on data from 2980 children and adolescents (mean age 12-13 years), confirmatory factor analysis established the construct validity of the scales, and hence, the multidimensional concepts underpinning creative self-beliefs. All measures evinced suitable levels of reliability, and invariance analysis supported configural, metric, and scalar invariance across gender, language background, and school type. Findings supported the convergent and divergent validity of scales against Big Five (openness and conscientiousness) personality measures. Implications of this three-factor creative self-beliefs model for researchers, educational practitioners, and youth are discussed.