Mental health challenges among Canadian post-secondary students have been on a steep upward trend in recent years, exacerbated by the COVID-19 pandemic. Yet, many students do not reach out to the mental health services available to them. To lessen or remove actual and perceived barriers, research has been exploring how to predict their intentions to seek help for their personal mental health challenges. Much of this work applies the widely used Theory of Planned Behaviour (TPB; Fishbein & Ajzen, 1980) which posits that behavioural intentions are best predicted by attitudes toward the behaviour; perceived normative expectations; and perceived behavioural control. Though the theory also posits that beliefs underlie and are formative of these three predictors, studies have largely neglected their measurement. This is problematic as it deviates from the TPB and frustrates efforts toward the development of interventions to enhance behaviours towards seeking help for mental health challenges. If they are to be effective, such interventions must be directed at changing salient beliefs. This research addresses this gap through a mixed-method sequential design. It provides a unique and valuable contribution to scholarship and practice by identifying and examining the role of students’ attitudinal, normative, and control beliefs with respect to their intentions to seek help. This is examined separately and together with the more traditionally studied direct predictors of attitudes, subjective norms, and perceived behavioural control (i.e., the formative constructs defined by the beliefs). Students relied on six salient beliefs concerning their intentions to seek mental health help: two behavioural, two normative, and two control beliefs. Student attitudes, subjective norms, and PBC mediated the links between salient beliefs and intentions, with PBC being the strongest predictor of intentions to help-seek. The findings help inform interventions to change the beliefs most associated with low intentions to get mental health support. / Thesis / Doctor of Philosophy (PhD) / This dissertation aims to advance the understanding of student intentions or—lack thereof—to seek mental health help following the onset of COVID-19. Salient beliefs that underlie student attitudes, subjective norms and perceived behavioural control are examined, using a Theory of Planned Behaviour approach. The research provides valuable theoretical and practical contribution. It identifies the beliefs held by post-secondary students post COVID-19, which can inform interventions intended to increase mental health service use. In Phase 1 of this study, students’ salient beliefs were examined through survey and interview methods. In Phase 2, I assessed these beliefs as direct predictors of their attitudes, subjective norms, perceived behaviour control, and as indirect predictors of mental health help-seeking intentions. Six beliefs were identified as relevant to student intentions to seek help, and findings lend support for the applied and scholarly value of the TPB to this area of study.