Objective: Nonsuicidal self-injury (NSSI) is a commonly occurring, yet historically poorly understood, mental health concern among post-secondary students. The present study sought to identify the current knowledge needs of university stakeholders to inform training efforts around effective NSSI response and student support on university campuses. Participants: Participants were 1,762 university students, staff, and student-staff (77% female) from seven universities in Canada, the USA, New Zealand, and Australia. Methods: Methods: Participants completed an online survey about their attitudes and knowledge of both general mental health and NSSI. Results: University stakeholders reported significantly greater stigma toward NSSI than mental illness in general. Student-staff reported greater perceived knowledge and comfort, and demonstrated greater knowledge of NSSI, than students and staff. Conclusions: Findings underscore the need for additional training and resources to reduce stigma and increase knowledge about NSSI on university campuses internationally.