Purpose: Although long-term viral suppression and antiretroviral therapy (ART) success depend on sustained adherence, adolescents’ adherence rates are suboptimal. Optimal adherence is influenced by various factors. Since Sub-Saharan Africa is home to over 80% of adolescents living with human immunodeficiency virus (HIV) and considering their unique characteristics and susceptibility to poor adherence, it is crucial to provide updated knowledge on adherence rates and their determinants among this population. This review aims to present up-to-date data on adherence rates and associated factors among HIV-positive adolescents in Sub-Saharan Africa. Methods: A systematic review was conducted following the PRISMA guidelines. The PubMed and Scopus databases were used to identify documents corresponding to the study's objectives. Eleven studies were included in this review after being selected from among all studies that were found online from 2017 to 2023. Results: The reported adherence rates ranged from 55% to 86%. In total, 32 factors were found to be related to adherence among HIV-positive adolescents in Sub-Saharan Africa. These included 12 adherence-facilitating factors and 20 adherence-inhibiting factors. The most often mentioned factors affecting adherence were advanced World Health Organization clinical stage (i.e., stage IV), ART dose and regimens, a lack of support, and violence victimization. Conclusion Our findings can help healthcare providers collaborate with HIV-positive adolescents to improve ART adherence and ensure the best possible health outcomes.