AimsThis systematic review aims to identify and synthesise the publicly available research testing treatments for mental health, cognition and psychological well-being in long COVID.MethodsThe following databases and repositories were searched in October–November 2023: Medline, Embase, APA PsycINFO, Cumulative Index to Nursing and Allied Health Literature, China National Knowledge Internet, WANFANG Data, Web of Science’s Preprint Citation Index, The Cochrane Central Register of Controlled Trials, Clinicaltrials.gov and the WHO International Clinical Trials Registry Platform. Articles were selected if they described participants with long COVID symptoms at least 4 weeks after SAR-CoV-19 infection, reported primary outcomes on mental health, cognition and/or psychological well-being, and were available with at least an English-language summary. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for systematic reviews were followed.ResultsThirty-three documents representing 31 studies were included. Seven tested psychosocial interventions, five pharmaceutical interventions, three natural supplement interventions, nine neurocognitive interventions, two physical rehabilitation interventions and five integrated interventions. While some promising findings emerged from randomised controlled trials, many studies were uncontrolled; a high risk of bias and insufficient reporting were also frequent.ConclusionsThe published literature on treatments for mental health, cognition and psychological well-being in long COVID show that the interventions are highly heterogeneous and findings are inconclusive to date. Continued scientific effort is required to improve the evidence base. Regular literature syntheses will be required to update and educate clinicians, scientists, interventionists and the long COVID community.