Introduction: Adolescents living with HIV 9 (ALHIV), particularly those with perinatal HIV, face unique challenges in achieving viral suppression, which is crucial for reducing morbidity, mortality, and HIV transmission. Despite global efforts to meet the UNAIDS 95-95-95 targets, viral suppression rates among ALHIV remain suboptimal. This study aimed to identify factors associated with viral suppression among adolescents aged 11–17 years with perinatal HIV in Indonesia. Methods: This retrospective study was conducted in a hospital in Indonesia among 11–17-year-olds living with HIV. Hospital medical records from 2019 to 2022 were used to assess the participants' adherence and viral load suppression. We employed descriptive statistics, including frequencies, proportions, and regression analysis, to determine the relationship between demographic and clinical factors, adherence, and viral load suppression. Result: The study achieved viral suppression in 69.4% of the participants. Multivariate analysis revealed that good adherence to ART (≥95%) was significantly associated with higher odds of viral suppression (AOR: 4.19, p < 0.01). A baseline CD4 count greater than 200 cells/μL (AOR: 3.20, p = 0.03) and the absence of a history of tuberculosis (AOR: 1.56, p = 0.04) significantly predicted viral suppression. Additionally, researchers observed a positive correlation between the duration of antiretroviral therapy (ART) and the viral suppression rate. Discussion: The results of this study show that longer antiretroviral therapy (ART) duration increases the likelihood of achieving viral suppression. The results of this study are consistent with those of previous research, showing that adolescents who had been on ART for 6 to 12 months were more likely than those on treatment for a more extended period to experience viral non-suppression (viral load > 400 RNA copies/mL). Conclusion: Viral suppression among ALHIV in Indonesia is influenced by adherence to ART, baseline immune status, and history of TB. Addressing barriers to adherence and integrating TB-HIV care are essential strategies to improve outcomes for this vulnerable population. 2025, Bentham Science Publishers