Interaction in online learning has a significant role in enhancing students' engagement and learning outcomes. Students' and teachers' perceptions of online learning interaction are essential for online learning success. Despite the various findings in students' and teachers' perceptions of online learning interaction, the perspective comparison of these two groups of participants' perceptions lacks empirical evidence. This study was conducted to investigate and compare teacher and student perceptions of interaction patterns in their online learning experiences. A mixed methods design was used, and samples were drawn from 694 students and 144 teachers at a public university in Vietnam. The quantitative findings showed that both students and teachers had similar positive perceptions of the overall interaction, but there were significant differences in their perceptions of student-student interaction and student-instructor interaction. The qualitative data revealed significant explanations for the similarities and differences. Implications of the findings were provided, alongside suggestions for future research.