Although young people's face-to-face and digital social interactions have been frequently examined in relation to their psychological well-being, few studies have considered how day-to-day variations in digital social interactions relate to fluctuations in self-esteem. To fill this gap, this study used a daily diary method over a five-day period to examine the same-day and lagged-day associations between the quantity and quality of social interactions (i.e., face-to-face vs. digital) and self-esteem in a diverse sample of young adults (N = 219; 51% women, 49% men; M age = 21). Additionally, this study also investigated the moderating role of social anxiety on this relation. Over a five-day period, participants completed a daily diary checklist at the end of each day and reported on their social interactions (i.e., quantity and quality) and self-esteem for that day. Results showed that the quality of interactions via face-toface settings and text messaging as well as the quantity and quality of interactions via social media were positively associated with self-esteem. Only the quality of faceto-face interactions on the prior day positively predicted self-esteem on a given day.Social anxiety moderated the same-day associations between quality of interactions via face-to-face and text messaging, and self-esteem. Findings suggest that only high-quality face-to-face interactions may be associated with longer lasting gains to psychological well-being. The implications of these exploratory findings for our understanding of the role of emerging technologies are discussed.