The aim of this cross-sectional study was to investigate the associations between oral health-related quality of life (OHRQoL) and socioeconomic and demographic variables, suicidal ideation, self-perception of oral health, and experiences of dental care in the Brazilian adult LGBTIQ+ population. A sample of 464 participants completed self-administered online questionnaires and provided information for OHRQoL assessment, using the OHIP-14 instrument at three hierarchical levels of explanatory variables: LGBTIQ+ identities; socioeconomic and demographic data and existential suffering; and self-perception of oral health and experience of dental care. The collected data were fitted to hierarchical multiple logistic regression models, in which the associations between each independent variable with the OHIP-14 prevalence outcome were analyzed. The OHIP-14-prevalence index showed that 33.2% of the participants answered 'frequently' or 'always', and the highest frequencies were obtained for the psychological discomfort (27.8%), psychological disability (18.3%), and physical pain (17.5%) domains. According to the adjusted final model, LGBTIQ+ individuals who were more likely to have their OHRQoL affected were those who were indifferent (OR=3.21; 95% CI: 1.26-8.20), dissatisfied (OR=10.45; 95% CI: 3.86-28.26), or very dissatisfied (OR=53.93; 95% CI: 12.12-239.93) with their oral health status, and also those who had or have difficulty accessing dental treatment (OR=2.06; 95% CI: 1.24-3.41) (p<0.05). It may be concluded that the OHRQoL of the investigated Brazilian LGBTIQ+ population showed associations with individual aspects and with access to dental services.