Sexual and gender minorities (SGM; i.e. lesbian, gay, bisexual, transgender, queer, intersex, asexual and other identities aka LGBTQIA+) experience homelessness at disproportionately higher rates than their cisgender and heterosexual peers. Adverse childhood experiences (ACE)—experiences of abuse, neglect, or challenges in the family setting—have been identified as a key risk factor for experiencing homelessness. The present study assessed the relationship between ACE and first-time homelessness in a community sample of SGM adults in South Texas. Participants (n = 910) completed a cross-sectional survey and logistic regression models were used to estimate associations with first-time homelessness childhood and adulthood. Adjusting for covariates, the odds of first-time homelessness increased by 1.58 times in childhood (95% CI = 1.36–1.84) and 1.33 times in adulthood (95% CI = 1.21–1.46) for every additional ACE reported. Specific ACE categories were also associated with homelessness experiences. Research is needed to understand the breadth of causes and consequences of homelessness among SGM individuals.