Young Black men who have sex with men (BMSM) in the USA face disproportionate rates of HIV incidence. Mental health vulnerabilities, including depression, anxiety, substance use, and trauma, further exacerbate the HIV epidemic among this population. Internalized homophobia, discrimination, and depression contribute to elevated rates of suicidal behavior among young BMSM, which in turn may influence engagement in HIV prevention behaviors, such as HIV testing. However, limited research has examined the interplay among suicidal behaviors, internalized homophobia, depression, and HIV testing among young BMSM. This study utilized syndemic theory to explore the relationships among these factors in a sample of 400 young BMSM ages 18–29. Results indicate alarming rates of suicidal behavior among young BMSM, with significant associations among internalized homophobia, depression symptoms, suicidal behavior, and HIV testing. The findings underscore the urgent need for targeted mental health interventions and HIV prevention services tailored to address the unique challenges faced by young BMSM. Comprehensive, multi-level, community-centered interventions are essential to address the syndemics affecting young BMSM, promoting holistic health and well-being while improving outcomes across the HIV prevention continuum.