There are a number of measures of life satisfaction for use with adolescent samples. The adapted Cantril Ladder is one such measure. This has been collected by the Health Behaviour in School-aged Children (HBSC) study in HBSC member countries across Europe and North America for several survey cycles, dating back to 2002. Although this measure has been piloted in the HBSC member countries, and analysed and reported in several international scientific journals and reports, it has never been formally validated. This study aims to be a first step in validating the adapted Cantril Ladder to establish if it is fit for purpose in the measurement of global life satisfaction among adolescents in Scotland. The study found that across samples of 11-15 year old pupils, the Cantril Ladder showed good reliability, and among 11 year olds, better than that of the Students’ Life Satisfaction Scale, an often used measure in adolescent samples. The Cantril Ladder also showed good convergent validity with other emotional well-being measures, perceived health and subjective health. Gender differences were noted in the convergent analysis suggesting gender differences in factors influencing or influenced by life satisfaction measured using this instrument.