Background: The Pacific Islands have some of the highest rates of suicide in the Western Pacific region. The purpose of this study was to systematically review the literature on suicidal behaviour in the Pacific Islands. Methods: A comprehensive search of Web of Science, PubMed, PsycINFO, Cochrane, CINAHL and Embase databases was conducted for all articles published until 1st February 2021. Inclusion criteria included papers that referred to a pre-specified list of Pacific Islands. Papers referring exclusively to other countries were excluded. Other exclusion criteria included not being about suicide or suicide attempts or not presenting original research. Narrative synthesis was applied without meta-analysis. The review followed PRISMA guidelines. Findings: A total of 36 papers were included for review. Of the Pacific Islands, Kiribati has the highest age-standardised rate of suicide mortality. Key risk groups across the Islands included youth, people of Indian ethnicity in Fiji (a prominent ethnic group in Fiji), and Indigenous peoples across other Islands. Prominent methods were self-poisoning and hanging. A distinct lack of intervention studies was found. Interpretation: Overall, the Pacific Islands appear to have relatively high rates of suicide and suicide attempts compared to other countries in the region. This was particularly striking among youth. This review provides important directions for future suicide prevention activities, including means restriction, sensitive media/community coverage, enhanced surveillance, and the development and evaluation of interventions tailored to the needs of young people and other cultural groups.