This study aims to map the field of research on informal caregivers’ use of online support communities (OSCs) and synthesize different theoretical, conceptual, and methodological approaches by conducting a scoping review of 61 articles. The results suggest the multidisciplinary nature of the topic, with scholars from communication, medical and healthcare, business, sociology, and other disciplines addressing various research perspectives. Scholars from various disciplines tend to examine informal caregivers’ communication messages in OSCs, with significant attention given to types of social support seeking and provision based on social support theories. However, other communication behaviors (e.g., self-disclosure) received less attention, and their conceptualization varied across studies. This review also identified a trend within the medical and healthcare disciplines of investigating caregiver well-being outcomes associated with OSCs use with few theoretical foundations, and using diverse research methods. Drawing on insights from multidisciplinary perspectives, suggestions are made to inform future research agendas for communication scholars.