Correctional workers (CWs) endure several operational stressors (e.g., exposures to potentially psychologically traumatic events) and organisational stressors (e.g., shift work, staff shortages), which are associated with positive screens for mental disorders and self-reports of suicidal behaviours and thus urgently warrant further inquiry. The Canadian Provincial and Territorial Correctional Worker Mental Health and Well-Being Study (CWMH) used an online survey to collect data from Canadian correctional service organisations across all 13 provinces and territories. This national Canadian study investigates suicidal behaviours among CWs across diverse occupational roles and provincial and territorial jurisdictions (n=3740, 50.1% female). The results estimated prevalence proportions for self-reported past-year and lifetime suicidal thoughts, planning, and attempts across the 13 Canadian provincial and territorial correctional systems, with the exceptions of past-year suicidal planning in Alberta, Newfoundland and Labrador, New Brunswick, and Yukon where jurisdictional considerations and requests precluded the inclusion of select questions. Substantial proportions of participants reported past-year or lifetime suicidal ideation (i.e., 9.1%, 29.2%, respectively), planning (i.e., 4.1%, 14.7%, respectively), or attempts (i.e., 0.8%, 7.2%, respectively). Sociodemographic variables (i.e., sex, age, marital status, total years of service, occupational category) were associated with past-year and lifetime suicidal behaviours. Findings provide opportunities for future research and can inform tailored efforts by clinicians, service providers, and organisational leaders to support proactive interventions and treatments, including supporting the partners and families of CWs, fostering social support networks, and improving access to timely mental health treatment.