Postgraduate research students have poorer mental health than the general community. Improving their experiences of diversity, inclusion, and belonging at university may bolster their overall wellbeing and reduce poor mental health outcomes. The aim was to explore postgraduate research students' views on diversity, inclusion, and belonging, to understand how these experiences impact their mental health and wellbeing, and to identify ways to improve their experiences. Thirty-one postgraduate research students (aged 24-68 years, M = 35.78 years, SD = 10.38; 69% female), enrolled in health sciences degrees at a research-intensive Australian university, completed either an online qualitative survey or participated in a focus group. Content analysis was undertaken to identify core themes. The three main content areas included: diversity (promoting diversity, staff and student training), inclusion (support from supervisors and peers, support in the perinatal period) and belonging (social isolation, suggestions to improve a sense of belonging). Most participants had not received training in diversity, inclusion and belonging, and identified this as an important area of need. Strategies to reduce isolation may potentially improve students experience of inclusion and belonging.