This study investigated the relationships between self-efficacy, self-regulation, and teaching presence, cognitive presence, and learning engagement during the pandemic. A total of 1435 undergraduate students in Korea completed an online survey on their learning experiences during COVID-19. The findings indicate that self-efficacy had a positive relationship with teaching presence and cognitive presence as well as self-regulation. No direct relationship between self-efficacy on learning engagement was found; however, the relationship between self-efficacy and learning engagement was fully mediated by self-regulation, teaching presence, and cognitive presence. Self-regulation had a positive relationship with both cognitive presence and learning engagement. Teaching presence had a positive impact on cognitive presence, but not on learning engagement. However, cognitive presence fully mediated the relationship between teaching presence and learning engagement. In effect, this study lends support to the significance of the role of cognitive presence in online learning.