The role of childhood gender role nonconformity (CGNC) and childhood harassment (CH) in explaining suicidality (suicide ideation, aborted suicide attempts, and suicide attempts) was examined in a sample of 142 lesbian, gay, and bisexual (LGB) adults and 148 heterosexual adults in Austria. Current and previous suicidality, CGNC, and CH were significantly greater in LGB participants compared to heterosexual participants. After controlling for CGNC, the effect of sexual orientation on CH diminished. CGNC correlated significantly with current suicidality in the LGB but not in the heterosexual group, and only non-significant correlations were found for CGNC with previous suicidality. Controlling for CH and CGNC diminished the effect of sexual orientation on current suicidality. Bayesian multivariate analysis indicated that current suicidality, but not previous suicidality, depended directly on CGNC. CH and CGNC are likely implicated in the elevated levels of current suicidality among adult LGB participants. As for previous suicidality, the negative impact of CGNC on suicidality might be overshadowed by stress issues affecting sexual minorities around coming out. The association of CGNC with current suicidality suggests an enduring effect of CGNC on the mental health and suicide risk of LGB individuals.