Abstract Purpose Cancer research on sexual and gender minority (SGM) populations is gaining momentum. The purpose of this systematic review was to examine what is currently known in the research literature regarding patient-reported health outcomes after cancer treatment among SGM populations. Methods In March 2021, a medical librarian conducted a systematic keyword search on PubMed, Embase, Scopus, Web of Science, PsycINFO, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials. The primary inclusion criterion was assessment of at least one physical, psychosocial, emotional, or functional patient-reported health outcome related to the impacts of cancer diagnosis and/or treatment. Articles that met inclusion criteria were reviewed in their entirety, charted in a Word Table, and assessed for quality. Quality considerations included study design, sampling approach, diversity of sample, measures used, and analytic procedures. Studies were synthesized based on type of cancer study participants experienced. Results Sixty-four studies were included in the final analysis: most were quantitative, secondary analyses or cross-sectional studies with convenience samples, and focused on people with a history of breast or prostate cancer. Differences between sexual minority men and women in terms of coping and resilience were noted. Few studies reported on experiences of transgender persons and none reported on experiences of intersex persons. Conclusions A growing literature describes the patient-reported health outcomes of SGM people with a history of cancer. This study summarizes important between-group differences among SGM and heterosexual, cisgender counterparts that are critical for clinicians to consider when providing care. Implications for cancer survivors Sexual orientation and gender identity are relevant to cancer survivors’ health outcomes. Subgroups of SGM people have differential experiences and outcomes related to cancer and its impacts.