Reflection has been emphasized as crucial for learning and development. Yet, the social dimension of reflection is under-researched. Thus, this article proposes a conceptual framework to shed light on the social aspect of reflection and promote consistent and coherent research on group reflection. The authors first revisited reflection to recognize and justify the importance of group reflection as an explicit form of reflective practice in social contexts. Next, we conducted a 10-year (2010-2020) systematic review to examine the recent research on group reflection and identify gaps for future investigation. Based on the review findings, group composition and guidance on the practice were identified as two critical features in examining how individuals reflect at the interpersonal level to construct shared understanding within the group. Considering individuals' attributes as the source for various group compositions, we propose a three-dimensional framework to direct research on group reflection, including dimensions of (a) personal attributes, (b) group diversity, and (c) guidance on group reflection. This conceptual framework includes key attributes of group composition and four categories of guidance that may influence group reflection. Furthermore, we illustrate the application of the conceptual framework in three main research areas with specific examples of research questions. Last, we discuss the implications for future research beyond the conceptual framework.