<p>This study develops and analyzes a Caputo fractional model for HIV/AIDS transmission dynamics that incorporates drug-resistant strain and pre-exposure prophylaxis (PrEP). The purpose of this study is to explore the impact of key biological model parameters on transmission patterns of the disease. A novelty of our work relies on the fact that it utilizes a Caputo fractional operator that takes into account the impact of the past history of the disease on its current and future state and considers PrEP users and drug-resistant groups as crucial disease compartments. Basic model properties such as non-negativity, boundedness, existence, and uniqueness of the model solutions are examined. The basic reproduction number of the model is determined using the next generation matrix approach. Mathematical analysis of the model indicates that the HIV/AIDS-free equilibrium point is both locally and globally asymptotically stable if the basic reproduction number is less than unity and unstable if it exceeds unity. Sensitivity analysis highlights parameters most influential to the basic reproduction number, showing that reduced baseline transmission rate, PrEP discontinuation rate, and ART treatment failure rate, along with increased fraction of symptomatic individuals receiving ART medication, significantly decrease HIV/AIDS prevalence. Furthermore, simulation results indicate that by taking memory effects into account, a Caputo fractional derivative enhances a comprehensive understanding of HIV/AIDS dynamics, supporting the design of long-term and persistent intervention strategies.</p>