This paper presents the collective results of three independent studies in two countries, Australia and Iceland, aimed to develop a psychometrically sound adolescent coping scale, the Measure of Adolescent Coping Strategies (MACS). Study 1, relying on 3034 Australian and 6908 Icelandic adolescents, revealed five conceptually distinct first-order factors. Two second-order factors (dimensions) were derived: (a) adaptive coping encompassing stoicism/distraction, seeking social support, and self-care, and (b) maladaptive coping encompassing acting out and rumination. This factor structure was supported by multisample confirmatory factor analysis (MSCFA) across age, gender and national samples. Study 1 established evidence of discriminant validity. In Study 2, including 534 Australian adolescents, the factor structure was verified through confirmatory factor analysis (CFA). Studies 1 and 2 provided evidence of construct validity. Study 3, employing 118 Icelandic adolescents, established 16-week test-retest reliability and evidence of convergent validity. Therefore, the MACS is a short, reliable and valid scale to measure adolescent coping, thus enabling clinicians, researchers and educators to improve their practice when conducting research and guiding adolescents in developing effective coping methods.