Research rooted in self-determination theory (SDT) has shown that need-supportive teaching, which involves support for students' needs for autonomy, competence, and relatedness, is associated with better motivation, engagement, and achievement. However, there is a lack of research on how need-supportive teaching is associated with student well-being. In addition, past studies on SDT have mostly confined themselves to a limited range of cultural contexts, usually Western cultures. To address these gaps, we examined the association between need-supportive teaching and students' well-being across eight distinct cultural groups (Western Europe, East-Central Europe, East Europe, Latin America, English-speaking, Confucian, Southeast Asia, African, and the Middle East). We analyzed secondary data from the Program for International Student Assessment which included responses from 513,295 students nested in 70 societies. Data were analyzed using hierarchical linear modeling. Results indicated that need-supportive teaching was associated with better subjective, eudaimonic, and social well-being. Results held across the eight cultural groups and were robust to the inclusion of covariates at the individual (gender, socioeconomic status, immigration status, and parent support) and school (school socioeconomic status and percentage of local students within a school) levels. Our study provides strong support to the SDT assumption that need-supportive teaching is associated with optimal functioning across different cultural contexts. Theoretical and practical implications are discussed.