Abstract: This study examined mental health treatment nonutilization among sexual minority versus heterosexual Veterans with demonstrated psychiatric need. Data were analyzed from 820 Veterans with psychiatric need who participated in the National Health and Resilience in Veterans Study, which surveyed a nationally representative sample of U.S. military Veterans. Results revealed that current mental health service nonutilization did not differ between sexual minority versus heterosexual Veterans (70.5% vs. 74.0%). Significant interactions between sexual orientation and sex assigned at birth, primary source of health care (Veteran Affairs [VA] vs. non-VA), and beliefs that peers would blame them for their mental health problems were observed in analyses predicting current mental health treatment utilization. Among Veterans primarily utilizing VA health care, sexual minority Veterans were less likely than heterosexual Veterans to engage in mental treatment; among those primarily using non-VA, this pattern was reversed. Sexual minority Veterans were significantly more likely than heterosexual Veterans to report not knowing where to get help, not having adequate transportation, and having difficulty scheduling an appointment. Taken together, the results of this study suggest that rates of mental health nonutilization are high for both sexual minority and heterosexual Veterans, and that factors that influence utilization may differ by sexual orientation.