Background: To determine if thwarted belongingness in combination with frequent alcohol use increased suicidal and homicidal ideation when known predictors were controlled for (eg, depressive disorders, anxiety disorders, drug use, race, sex, age, and employment status). Method: This study utilized an archival database. Participants were 574 individuals at an outpatient substance abuse treatment facility who were under community corrections supervision. The average age was 34.5 (SD=10.9) years; there were 371 (64.6%) men and 287 (50.0%) Black participants. Data were originally gathered from faceto-face interviews with the participants by their case manager or an intake specialist when they entered treatment. Self-reported suicidal and homicidal ideation was used as a dependent variable in unadjusted and adjusted binary logistic regressions to determine the influence of thwarted belongingness and frequent alcohol use. Results: Thwarted belongingness alone (ie, without frequent alcohol use) was associated with risk for suicidal ideation, and was approaching significance for homicidal ideation. The combination of thwarted belongingness and frequent alcohol use was associated with the greatest risk for suicidal and homicidal ideation. Cocaine use and employment status were also identified as significant predictors for suicidal and homicidal ideation in the fully adjusted models. Conclusions: Thwarted belongingness in combination with frequent alcohol use seems to have a large and meaningful relationship with both suicidal and homicidal ideation. Additional research is needed to better understand the relationship between alcohol, thwarted belongingness, and outcomes such as suicide and homicide.