Although there is a growing body of research that suggests the mental health of graduate students differs from that of their undergraduate counterparts, studies examining international students at the graduate level are scarce. This study therefore compares mental health diagnoses, challenges and stressors experienced, and use of mental health support, of international and non-international students who identified as being graduate/professional students. Data from the 2019 Canadian National College Health Assessment were used to compare the international graduate students (n = 1,876) to their non-international peers (n = 4,809). Significant differences were found on prevalence of conditions, certain specific challenges that are experienced, and help-seeking behaviours. Overall, international and non-international students may experience similar challenges, but international students are less likely to seek support. The findings suggest a need for graduate advisors and student affairs professionals to recognize the unique experiences of international graduate students particularly with their help-seeking behaviours.