AbstractHigh rates of mental ill-health in postgraduate researchers (PGRs) represent a significant barrier to life satisfaction and academic success. Nevertheless, there is little knowledge about the extent and origins of mental health problems of PGRs in the UK. The current study addresses this gap by investigating the prevalence and provenance of anxiety, depression, sleep problems, subjective mental wellbeing, and suicide behaviours of PGRs in the UK. An online survey (N = 479) was used to measure the mental health outcomes and assess their relationships with demographic, trait and academic variables, policy, and social support. We found a high prevalence of mental ill-health and low levels of wellbeing in the current sample. Factors associated with poorer outcomes were female and non-binary gender, non-heterosexual identity, maladaptive perfectionism, workaholism and being in the 5th year of study or above. Resilience, adaptive perfectionism, higher levels of social support and positive evaluations of progress and preparation, departmental climate, and supervisory relationship were associated with more positive outcomes. The current findings contribute new knowledge about the prevalence of mental health symptoms in PGRs in the UK, implying that institutional efforts to improve PGR wellbeing should include strategies to promote equality, diversity, resilience, integration, social support, and work-life balance of PGRs.