Aim We sought: (a) to explore the roles of complex posttraumatic stress disorder (CPTSD), racism, and heterosexist discrimination in linking exposure to traumatic events and lifetime suicide attempt among sexually diverse racial and ethnic minority adults; and (b) to explore differences by race/ethnicity. Methods We used structural equation modeling methods (moderated mediation analysis) to analyze a sample of sexually diverse racial and ethnic minority adults from the National Epidemiological Study of Alcohol and Related Conditions (NESARC-III) dataset (n = 632). Descriptive results are included for underpowered subgroups. Results We found significant differences by racial/ethnic identity, with CPTSD mediating associations between trauma exposure and suicide attempt status among Hispanic respondents, but not Black respondents. Furthermore, racism and heterosexist discrimination amplified the effects of trauma exposure on CPTSD symptoms among Hispanic respondents. Conclusion CPTSD may be an important mechanism in the trauma-suicide connection among some sexually diverse racial and ethnic minority people. These findings have important implications for suicide prevention work among sexually diverse populations, including the need for interventions that integrate traumatic stress treatment and employ an intersectional approach, addressing the influence of racism and heterosexism, particularly for Latinx and Hispanic groups.