Homelessness is a complex social, economic and psychological issue, and compared with the general population, people experiencing homelessness suffer disproportionately from mental health and substance use issues. Evidence suggests that psychological interventions can improve the quality‐of‐life of people experiencing homelessness. A systematic review and meta‐analysis were conducted on studies identified in five databases. Global studies published before July 2023 were included. A total of 35 studies were identified from 30 independent trials conducted in five countries. Outcomes were divided into six domains: substance use, mental health, psychological wellbeing, health behaviour, antisocial behaviour and social outcomes. A meta‐analysis was performed on data from 22 studies investigating outcomes of substance use, abstinence, anxiety, depression and PTSD. Evidence demonstrates the effectiveness of psychological interventions for a range of outcomes affecting people experiencing homelessness. Cognitive behaviour therapy and motivational interviewing were deemed particularly effective across a range of outcomes and were also considered a cost‐effective option. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement.