IntroductionA core facilitator of the transition from suicidal thoughts to suicide attempt is the individual’s capacity for suicide. Suicide capacity is a theoretically universal concept adaptable for specific groups that is hypothesised to comprise three contributing factors: acquired capability, for example, previous self-harm; dispositional, such as genetic influences and practical, knowledge of and access to lethal means. Given that suicide capacity as a concept is continuing to develop, a review and synthesis of the current literature is timely to ensure future research and development of suicide prevention strategies are based on evidential knowledge. The aim of this review is to map the available evidence to provide an overview of factors that contribute to an adult’s capacity for suicide.Methods and analysisThis review will encompass five stages. Studies will be identified through broad search strings applied to 11 academic databases: Academic Search Ultimate, APA PsycArticles, APA PsycINFO, CINAHL, Psychology & Behavioural Sciences, & Sociology Source Ultimate via EBSCOHost Megafile Ultimate; PubMed; Science Direct; Wiley Online; Taylor & Francis and ProQuest dissertations and theses. Grey literature databases and key suicide organisations will also be searched for relevant literature. Two reviewers will independently screen titles and abstracts then review full texts to identify articles meeting inclusion criteria. Articles will be assessed for eligibility based on suicide attempt history, primary research study design, language and publication date. Data from eligible full texts will be extracted using a predesigned template for analysis. The synthesisation method will be textual narrative synthesis with an incorporated quality appraisal checklist tool.Ethics and disseminationEthics approval is not required for this scoping review as no human participants are involved. Study findings will be shared with key suicide organisations, through peer-reviewed publications, and conference presentations.