Many individuals who identify as lesbian, gay, bisexual, queer, and with other non-heterosexual orientations (LGBQ+) experience stigma, prejudice, and/or discrimination because of their sexuality. According to minority stress and identity development theories, these experiences can contribute to difficulties with self-acceptance of sexuality. Lower self-acceptance is considered a risk factor for adverse mental health outcomes. The current review aims to investigate whether self-acceptance of sexuality is associated with minority stressors or difficulties with mental health in LGBQ+ individuals, as well as whether there are differences in self-acceptance between different sexual orientations. Five bibliographic databases were searched. Thirteen studies were identified which used quantitative methodology to investigate associations between self-acceptance, minority stressors, and/or mental health within LGBQ+ samples, or differences in self-acceptance between different sexual orientations. The results from these cross-sectional studies suggested that lower self-acceptance of sexuality was associated with higher levels of self-reported minority stressors, including a lack of acceptance from friends and family, a lack of disclosure to others, and internalized heterosexism. Lower self-acceptance of sexuality was associated with poorer mental health outcomes, including greater global distress, depression symptoms, and lower psychological well-being. There was no significant relationship with suicidality. Studies also found that LGBQ+ individuals had lower general self-acceptance compared to heterosexual participants, bisexual individuals had lower sexuality self-acceptance compared to lesbian/gay individuals, and lesbian women had lower sexuality self-acceptance compared to gay men. Given the potential importance of self-acceptance for LGBQ+ populations, further research is required with more robust methodology. Self-acceptance could be a potential target in clinical interventions for LGBQ+ individuals.