AimsTo summarise and critically appraise the evidence of mindfulness-based interventions for psychological distress in patients with cancer and their partners.DesignA critical review.MethodsThe critical appraisal checklists of the Centre for Evidence-Based Management were utilised for the quality appraisal while reporting the results using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement.Data SourcesSix electronic databases were searched, including MEDLINE, CINHAL, Embase, PsycINFO, the Cochrane Library, and Web of Science, from inception to August 2023.ResultsA total of six studies were included. Mindfulness-based interventions in general improved psychological distress among patients with cancer and their partners. However, the components of the interventions varied.ConclusionTreating patients with cancer and their partners as a unit may improve psychological distress for both parties. It is recommended that cancer couples be involved in mindfulness-based interventions simultaneously to achieve positive effects. Future research into the effectiveness and best practices of mindfulness-based interventions remains necessary.Implications for the Profession and/or Patient CareThe findings provide information and evidence for improving psychological distress among patients with cancer and their partners to guide the development of a mindfulness-based intervention.Impact Mindfulness-based interventions were effective in improving psychological distress in patients with cancer and their partners. The effectiveness of mindfulness-based interventions varied based on intervention formats. Engaging cancer couples in mindfulness-based intervention together may have a positive impact on both partners.Reporting MethodPreferred Reporting Item for Systematic Reviews and Meta-Analyses Statement 2020.Patient or Public ContributionNo Patient or Public Contribution.