Background: Sexual minorities experience several health disparities. However, risk/protective factors relevant to cognitive health of sexual minority older adults (SMOAs) have not been fully investigated. The aim of this study was to quantify the impact of several psychosocial factors on both subjective and objective cognitive health in SMOAs. Methods: Thirty-nine cognitively unimpaired SMOAs and 30 heterosexual older adults (HOAs) completed an online survey to provide information on psychosocial risks (i.e., depression, anxiety, general stress), subjective cognitive decline (SCD), beliefs about their own memory and dementia worries. SMOAs also completed questionnaires on minority stress and outness. Twenty-seven SMOAs and 24 HOAs underwent a comprehensive neuropsychological assessment. General linear models were used to assess the relationship between psychosocial risks and cognitive health and interactions between sexual orientation and risk factors. Associations between minority stress, outness and cognitive health were assessed in SMOAs only. Results: SMOAs reported worse mental and subjective cognitive health than HOAs, but similar cognitive performance. Worse depression explained more negative beliefs about memory in SMOAs than HOAs. Anxiety and general stress were associated with worse attention/processing speed performance in SMOAs only. Minority stress was associated with higher risk of SCD for language and more negative beliefs about memory, while higher outness levels were associated with better short-term memory. Conclusions: Psychosocial risks affect cognitive health more severely in SMOAs than HOAs. Minority stress affects subjective cognitive health of SMOAs, while outness may provide cognitive resilience. Further investigations are needed to devise prevention strategies aimed at preserving cognitive health in SMOAs.