While understanding of mental health differs by culture, how cultures impact the mental health of social work students, who have mental health difficulties, remains to be evaluated. We compared the levels of, and relationships among mental health constructs, between social work students in the UK and Ireland, namely self-reported mental health problems (depression, anxiety and stress), mental health shame (shame towards mental health problems) and self-compassion (kindness towards yourself when things go wrong). UK social work students had lower levels of mental health problems and shame, and higher levels of self-compassion than Irish counterparts. Internal shame (how they would see themselves if they had a mental health problem) was most strongly related to mental health problems in UK students, while self-reflected shame (how they would feel if a relative had a mental health problem) was so in Irish students. Self-compassion was a significant predictor of mental health in both groups. Individualistic UK culture may help explain the strong association between internal shame and mental health, whereas more collectivistic Irish culture may help explain the link between reflected shame and mental health. Cultivating self-compassion may be an effective means to protect and enhance the mental health of these social work students. Despite the well-known mental health difficulties of social work students such as high levels of mental health problems and shame, and low levels of self-compassion, effective interventions remain to be evaluated. Moreover, whilst the levels of mental health constructs vary cross-culturally, how cultures impact the mental health has not been appraised in depth. This study aimed to compare the levels of, and relationships among mental health problems, mental health shame and self-compassion between social work students in the UK and Ireland. Opportunity samples of 120 UK students and 129 Irish students completed self-report measures regarding mental health problems, shame and self-compassion. Welch t-tests, correlation and regression analyses were conducted. Levels of mental health problems and shame were lower in British students than Irish students, while self-compassion was lower in Irish students. Internal shame was most strongly related to mental health problems in British students, while self-reflected shame was so in Irish students. Self-compassion was a significant predictor of mental health problems in both groups. Cultivating self-compassion, targeting internal shame in the UK, and reflected shame in Ireland, is recommended to protect and enhance the mental health of social work students.