General self-efficacy is a central personality trait often evaluated in surveys as context variable. It can be interpreted as a personal coping resource reflecting individual belief in one’s overall competence to perform across a variety of situations. The German-language Allgemeine-Selbstwirksamkeit-Kurzskala (ASKU) is a reliable and valid instrument to assess this disposition in the German-speaking countries based on a three-item equation. This study develops a French version of the ASKU and tests this French version for measurement invariance compared to the original ASKU. A reliable and valid French instrument would make it easy to collect data in the French-speaking countries and allow comparisons between the French and German results. Data were collected on a sample of 1,716 adolescents. Confirmatory factor analysis resulted in a good fit for a single-factor model of the data (in total, French, and German version). Additionally, construct validity was assessed by elucidating intercorrelations between the ASKU and different factors that should theoretically be related to ASKU. Furthermore, we confirmed configural and metric as well as scalar invariance between the different language versions, meaning that all forms of statistical comparison between the developed French version and the original German version are allowed.