Study Design: Systematic review. Objectives: To identify, critically appraise, and synthesize research findings on the associations between acceptance, quality of life (QOL), and mental health outcomes in individuals living with spinal cord injury (SCI). Methods: Five databases (PubMed, PsycINFO, Embase, Web of Science, and Scopus) were systematically searched. Studies were included if they provided findings on the association between acceptance and QOL, mental health outcomes, or both in an SCI population aged 16 years or older. Only peer-reviewed original quantitative and qualitative studies were included. Screening, quality assessment, and data extraction were conducted independently by two researchers. Findings were tabulated and synthesized by outcome. Results: Forty-one studies were included. Greater acceptance was consistently associated with greater global and psychological QOL, life satisfaction, sense of well-being, mental health, and with lower levels of depression and anxiety. Inconsistent evidence was found with regards to social QOL and post-traumatic stress disorder. Acceptance was generally not associated with adjustment outcomes further than two years into the future. Study quality of the quantitative studies was mostly fair (n = 17) followed by good (n = 13), and poor (n = 9). Conclusion: Health-care professionals may regard acceptance as a psychological resource they can aim to support in improving QOL and mental health following SCI. A range of methodological and conceptual limitations were present in the research. Future studies should prioritize longitudinal designs, consider dyadic effects, explore subjective meaning(s) of acceptance, and investigate the effectiveness of therapeutic approaches that stimulate the acceptance process. AA was responsible for designing and writing the review protocol, conducting the literature search, screening identified records, conducting quality assessment, extracting and synthesizing data, interpreting results, creating figures and tables, and writing the manuscript. SLR was responsible for screening identified records, conducting quality assessment, and extracting and synthesizing data. She further contributed with guidance and continuous feedback on the review protocol, tables and figures, and revisions of the manuscript. HK contributed with guidance and continuous feedback on the review protocol, tables and figures, and revisions of the manuscript. TEA was responsible for arbitrating potentially eligible studies and further contributed with guidance and continuous feedback on the review protocol, tables and figures, and revisions of the manuscript.