OBJECTIVE: People with head and neck cancer are up to three times more likely to die by suicide than the general population. There is an urgency to understand and address the growing rates of suicidality within this population. The objectives of this review are (1) to explore the risk factors for thoughts of suicide and self-harm, and suicide completion in patients with head and neck cancer, and (2) to understand the challenges and needs of patients impacted by head and neck cancer who have had thoughts of self-harm and suicide. METHODS: Mixed-methods systematic review following the PRISMA protocol. Electronic databases and grey literature searches were completed using MeSH terms and key word searches. A total of 3665 recorded were identified; with 36 studies included. Of these, 22 focussed on suicide completion, with sufficient data to conduct a meta-analysis on several important risk factors for suicide completion. These are sex, age, time since diagnosis and marital status. The remaining 14 studies reported on suicide ideation for this population, with the findings analysed within a narrative synthesis. Findings and clinical implications were refined with input from nine members of a head and neck cancer patient and public involvement group. FINDINGS: Risk of suicide ideation and suicide completion was greatest in male patients. Suicide completion was highest in patients within the first 6-months of diagnosis, who were widowed, or had cancer of the hypopharynx. Suboptimal pain and symptom management appeared related to a higher risk of suicide ideation. A therapeutic and supportive relationship with health and social care professionals was helpful in managing experiences of suicidal ideation. CONCLUSIONS: Health and social care professionals should identify, assess, support and follow-up regarding thoughts of suicide for patients with head and neck cancer. Clear pathways are necessary for the management of suicidality, to include appropriate referrals to psychiatry/psychology, supportive interventions to include medications that can help with pain, distress or other symptoms.