We investigated perceived impacts of COVID-19 on the delivery of adolescent HIV treatment and prevention services in sub-Saharan Africa (SSA) by administering a survey to members of the Adolescent HIV Prevention and Treatment Implementation Science Alliance (AHISA) from February to April 2021. We organized COVID-19 impacts, as perceived by AHISA teams, under three themes: service interruptions, service adjustments, and perceived individual-level health impacts. AHISA teams commonly reported interruptions to prevention programs, diagnostic testing, and access to antiretroviral therapy (ART). Common service adjustments included decentralization of ART refills, expanded multi-month ART distribution, and digital technology use. Perceived individual-level impacts included social isolation, loss to follow-up, food insecurity, poverty, and increases in adolescent pregnancies and sexually transmitted infections. The need for collaboration among stakeholders were commonly cited as lessons learned by AHISA teams. Survey findings highlight the need for implementation science research to evaluate the effects of pandemic-related HIV service adaptations in SSA.