Learner well-being is one of the most important factors to be considered in foreign language education, but little is currently known about its socio-cultural aspects. In view of this, the present study attempted to develop a measurement scale for the sociocultural well-being of EFL learners based on literature analysis, semi-structured interviews, and multiple rounds of focus group discussions. Utilizing questionnaire data from 1341 Chinese EFL learners, item analysis, exploratory factor analysis, and confirmatory factor analysis were conducted to examine the reliability and validity of the scale. The final scale comprised two dimensions (social well-being and cultural well-being)and five sub-dimensions (social integration, social acceptance, social contribution, cultural awareness, and cultural recognition),totaling 35 items. Statistical analyses affirmed the developed scale’s high reliability and validity, meeting established psychometric criteria. Consequently, this scale can serve as a robust and effective tool for researching the sociocultural well-being of EFL learners in the Chinese educational context.