Background: As compared to their older peers, youth with HIV (YWH) are less likely to attain viral suppression and have higher rates of sexually transmitted infections (STI). In this exploratory study, we examine the relationship between HIV viral suppression, STI testing, and STI diagnosis among YWH receiving care at a clinic in the southern United States. Methods: Data from 933 clinical visits (2017–2020) were aggregated into singular patient records for YWH aged 10–24 years in Alabama ( N = 139). Analyses included univariate generalized linear mixed models performed with the PROC GLIMMIX procedure approximating the marginal likelihood by using Laplace’s method. Results: Sample median age was 22 years at the index visit. Most YWH were 20–24 years old (69.1%), male (67.6%), and identified as Black (77%); 58.3% were virally unsuppressed at index visit. YWH who identified as White or of other races had 4.79 times higher odds of being virally suppressed as compared to Black YWH ( p < .01); STI testing behavior and STI positive diagnosis were associated with lower odds of being virally suppression. Conclusions: Findings suggest that among YWH, receiving STI testing and having an STI diagnosis is associated with a lack of viral suppression, suggesting that extra efforts may be necessary to support YWH who have an STI to attain suppression. Research is needed to examine individual behaviors, structural forces, and clinic features that could impact STI care engagement, specifically among unsuppressed YWH.