ABSTRACTWith the rise of positive psychology in the field of second/foreign (L2) language acquisition, an increasing number of studies have delved into the factors influencing L2 engagement. While the interplay between environmental and personal factors has been acknowledged, we know little about whether and how different sources of social support influence L2 engagement via personal sources. To fill the gap, the current study recruited 649 Chinese English as a foreign language undergraduates and measured their perceived social support, L2 resilience, control, and engagement. Correlation analyses found that the four variables were positively correlated. Structural equation modeling analysis revealed that out of the three sources of social support, only teacher support had a direct impact on L2 engagement. Additionally, L2 resilience and control co‐mediated the path between teacher support and L2 engagement. Further inspection found that L2 resilience mediated the path from teacher support to all four dimensions of L2 engagement. However, L2 control only mediated the path from teacher support to cognitive and emotional engagement. The findings echoed the importance of teacher support in motivating L2 learning behaviors. Theoretical and pedagogical implications are also discussed.