The purpose of the current study is to develop the Adolescent Happiness Scale (AHS). A systematic approach was utilized for developing the scale. In this study, the data were collected from 1136 adolescents including 490 females and 646 males between 11-17 years of age. The psychometric properties of AHS were analyzed by means of item analysis, exploratory and confirmatory factor analyses, criterion-related validity, internal consistency and test-retest methods. The exploratory and confirmatory factor analyses results revealed that the scale had a single-factor structure. Within the scope of the criterion-related validity studies, significant positive correlations were found between AHS and positive affects and overall happiness levels, and a significant negative correlation was found between AHS and negative affects. The internal consistency coefficient of AHS was 0.92 for the first study and 0.91 for the second study. Test-retest reliability coefficient was determined to be 0.74. In conclusion, AHS can be recommended as a reliable and valid tool in measuring the happiness level of adolescents.