Friends and family members can be important sources of support for people who are or have been suicidal. This review aimed to synthesise qualitative evidence regarding carers' perspectives of supporting someone who has experienced suicidal behaviour. Methods: Five electronic databases (Web of Science, CINAHL, PsychINFO, MEDLINE, and SocINDEX) were searched from inception to May 2022. Eligible qualitative studies were published in English and investigated the caring experiences of friends or family members of people who had experienced suicidal behaviour, defined as any form of suicidal ideation and/or attempts. Studies focused on non-suicidal self-injury or suicide bereavement were excluded. Data from 19 eligible studies were analysed using thematic synthesis. Results: Initial carer reactions to suicidal behaviour included profound anxiety and intensive monitoring for signs of increased suicide risk amongst those they supported. Carers also reported significant challenges with understanding how to provide effective interpersonal support following suicidal crises. Professional support was perceived to be most effective when provided in a timely, interpersonally sensitive and safety-focused manner. However, several studies detailed carers' difficulties accessing appropriate support and challenges managing their own distress. Conclusions: Carers face significant challenges with knowing how to respond to suicidal behaviour, where to find appropriate help, and how to manage their own distress.