Background: Depression is a common mental health concern among college students. To better understand students’ service needs, it is imperative to explore their perceptions of professional treatments and help-seeking intentions. The existing literature highlighted the need to investigate students’ etiological beliefs about depression. This study examined students’ beliefs about the biological, psychosocial, and systemic causes of depression and the relationship between such beliefs and their perceptions of antidepressants, counselling, and help-seeking intentions. Methods: 201 college students were recruited from Canada and the USA to complete an online survey consisting of measures on etiological beliefs, attitudes toward treatments, and help- seeking intentions. Using a series of hierarchical regression analyses, we examined the associations between etiological beliefs and measures of treatment attitudes and help-seeking intentions, while controlling for sex and depression status. Results: The results showed that endorsing biological explanations of depression was positively associated with the perceived benefits of antidepressants and negatively linked to the perceived risks of antidepressants. Endorsing psychosocial explanations was positively associated with help-seeking intentions for suicidal thoughts. Moreover, male students were more likely to view counselling as risky and less likely to see the benefit of antidepressants and counselling than female students. Last, students with higher depressive symptoms were less likely to engage in help-seeking and more likely to see the risk of counselling. Conclusions: Understanding students’ etiological beliefs about depression could help tailor effective mental health interventions on college campuses and improve support for students with depression and suicidal thoughts.