INTRODUCTION: Young adults with HIV (YWH) experience worse clinical outcomes than adults and have high rates of substance use (SU) and mental illness that impact their engagement in care and adherence to antiretroviral therapy (ART). The intervention for Virologic Suppression in Youth (iVY) aims to address treatment engagement/adherence, mental health (MH) and SU in a tailored manner using a differentiated care approach that is youth friendly. Findings will provide information about the impact of iVY on HIV virological suppression, MH and SU among YWH who are disproportionately impacted by HIV and at elevated risk for poor health outcomes. METHODS AND ANALYSIS: The iVY study will test the effect of a technology-based intervention with differing levels of resource requirements (ie, financial and personnel time) in a randomised clinical trial with an adaptive treatment strategy among 200 YWH (18-29 years old). The primary outcome is HIV virological suppression measured via dried blood spot. This piloted and protocolised intervention combines: (1) brief weekly sessions with a counsellor via a video-chat platform (video-counselling) to discuss MH, SU, HIV care engagement/adherence and other barriers to care; and (2) a mobile health app to address barriers such as ART forgetfulness, and social isolation. iVY has the potential to address important, distinct and changing barriers to HIV care engagement (eg, MH, SU) to increase virological suppression among YWH at elevated risk for poor health outcomes. ETHICS AND DISSEMINATION: This study and its protocols have been approved by the University of California, San Francisco Institutional Review Board. Study staff will work with a Youth Advisory Panel to disseminate results to YWH, participants and the academic community. TRIAL REGISTRATION NUMBER: NCT05877729.