In 2016, an estimated 1.5 million adolescent girls and young women were living with HIV infection in Eastern and Southern Africa, where HIV prevalence among adolescent girls and young women is more than twice that of their male peers. In this report, analysis of data from Population-based HIV Impact Assessment surveys conducted during 2015–2017 in seven countries in Eastern and Southern Africa found that the prevalence of HIV infection among adolescent girls and young women was 3.6%. Among those who were HIV-positive, 46.3% reported being aware of their status, and among those aware of their HIV-positive status, 85.5% reported current antiretroviral treatment (ART) use. Overall, viral load suppression among HIV-infected adolescent girls and young women, regardless of status awareness or current use of ART, was 45.0%, well below the UNAIDS target of 73%. There is a need to design, implement, and evaluate strategies aimed at ensuring HIV-positive adolescent girls and young women know their HIV status and are on ART treatment to improve their immunity status and reduce transmission to others.