In view of the growing interest regarding binge-watching (i.e., watching multiple episodes of television (TV) series in a single sitting) research, two measures were developed and validated to assess binge-watching involvement (“Binge-Watching Engagement and Symptoms Questionnaire”, BWESQ) and related motivations (“Watching TV Series Motives Questionnaire”, WTSMQ). To promote international and cross-cultural binge-watching research, the present article reports on the validation of these questionnaires in nine languages (English, French, Spanish, Italian, German, Hungarian, Persian, Arabic, Chinese). Both questionnaires were disseminated, together with additional self-report measures of happiness, psychopathological symptoms, impulsivity and problematic internet use among TV series viewers from a college/university student population (N = 12,616) in 17 countries. Confirmatory factor, measurement invariance and correlational analyses were conducted to establish structural and construct validity. The two questionnaires had good psychometric properties and fit in each language. Equivalence across languages and gender was supported, while construct validity was evidenced by similar patterns of associations with complementary measures of happiness, psychopathological symptoms, impulsivity and problematic internet use. The results support the psychometric validity and utility of the WTSMQ and BWESQ for conducting cross-cultural research on binge-watching.