Background: The effectiveness of cognitive-behaviour therapy with young people may be influenced by a young person's capacity for self-reflection and insight. Clinicians who assess clients' proficiencies in these cognitive capacities can better tailor cognitive and behavioural techniques to the client, facilitating engagement and enhancing treatment outcome. It is therefore important that sound instruments for assessing self-reflection and insight in young people are available. Aims: The aim of the current study was to translate and adapt the Self-Reflection and Insight Scale (SRIS) for use with a child and adolescent population (Study 1), and to evaluate the psychometric properties of the resulting measure, the Self-Reflection and Insight Scale for Youth (SRIS-Y; Study 2). Method: In Study 1 (n = 145), the comprehensibility of the SRIS-Y was assessed in a community sample of children and adolescents. Study 2 (n = 215) then explored the reliability and structural, convergent, and divergent validity of the SRIS-Y. Results: The SRIS-Y was found to be comprehensible to young people, and had good reliability and structural validity. Conclusions: It appears that the SRIS-Y is a sound instrument for assessing therapy-relevant cognitive capacities in young people, of potential benefit in both research and clinical contexts. Future research foci include the predictive validity of the instrument.