Most research has examined flipped learning within the context of face-to-face (F2F) instruction. However, previous research has not effectively explored the possibility of how online synchronous flipped learning influences pre-service teachers (PSTs) in teacher education programs during Coronavirus disease (COVID-19). Recognizing the gap in the literature, this paper explored three aspects of online synchronous flipped learning by understanding 1) PSTs' learner engagement, 2) self-directed learning, and 3) learner satisfaction in a Korean university. The data was collected from Korean PST's interviews, reflection notes, and course evaluations. The thematic analysis was used to analyze qualitative data sources. The study findings showed that PSTs favored a synchronous online FL because it encouraged them to engage in various collaborative activities through Zoom breakout sessions. Also, pre-class materials from online FL can positively enhance the PSTs' self-directed learning process. Based on these findings, this study provides suggestions on how to effectively implement online synchronous flipped learning in teacher education programs.