Background: The existing literature has predominantly focused on instructor social presence in videos in an asynchronous learning environment and little is known about student social presence on webcam in online learning in the context of COVID-19. Objectives: This paper therefore contrasts students' and teachers' perspectives on student social presence on webcam in synchronous online teaching through co-orientation analysis. Methods: Data were collected through an online questionnaire with 14 statements that measured participants' perceptions of webcam use in three constructs in social presence (i.e., emotional expression, open communication, and cohesion). 154 students and 36 teachers from two higher education institutions in Hong Kong responded to the questionnaire, and their responses were analysed using the co-orientation model. Results and conclusion: Results reveal the perceptual gaps between teachers and students on the use of webcam to promote student social presence by showing how teachers were comparatively more positive about its impacts for learning and consistently overestimated students' preference for it. Through analysing individual constructs/items, this paper argues that using webcams in synchronous online learning could enhance student social presence only to a limited extent in that it may help improve emotional expression and open communication but not cohesion. Implications: The paper advises against the adoption of a clear-cut policy that webcams should be either recommended or not recommended for online learning. Instead, teachers should take into account students' perspective to find out the types of activities that are apt for using webcams in online learning, and reflective tasks and oral assessments were amongst the ones considered appropriate by students in the study.