Antiretroviral therapy (ART) has significantly extended the lifespan of people living with Human Immunodeficiency Virus (HIV) or Acquired Immunodeficiency Syndrome (AIDS), thereby transforming the disease into a manageable chronic condition. However, this increased longevity has led to a higher incidence of non-AIDS-defining cancers (NADCs) among this population. In this holistic review, we explore the complex interactions between HIV, ART, and cancer development, focusing on how ART influences tumor initiation and progression in people living with HIV/AIDS (PLWHA). Our findings from this reveal several critical aspects of cancer risk in PLWHA. Firstly, while ART restores immune function, it does not fully normalize it. Chronic immune activation and persistent inflammation continue to be prevalent, creating a conducive environment for oncogenesis. Additionally, PLWHA are more susceptible to persistent infections with oncogenic viruses such as human papillomavirus (HPV) and Epstein–Barr virus (EBV), further increasing cancer risk. Some ART drugs have been implicated in genotoxicity and mitochondrial dysfunction, potentially promoting tumorigenesis. ART-induced metabolic changes, including insulin resistance and dyslipidemia, are also associated with heightened cancer risk. Common NADCs in PLWHA include lung cancer, liver cancer, anal cancer, and Hodgkin lymphoma, each with distinct etiologies linked to both HIV-related and ART-related factors. The interplay between HIV infection, chronic inflammation, immune restoration via ART, and the direct effects of ART drugs creates a unique cancer risk profile in PLWHA. Although ART reduces the incidence of AIDS-defining cancers, it does not confer the same protective effect against NADCs. Persistent HIV-related inflammation and immune activation, despite viral suppression, are key factors in cancer development. Additionally, long-term exposure to ART may introduce new oncogenic risks. These insights highlight the need for integrated cancer screening and prevention strategies tailored to PLWHA. Future research is needed to focus on identifying biomarkers for early cancer detection and developing ART regimens with lower oncogenic potential. Healthcare providers should be vigilant in monitoring PLWHA for cancer and adopt comprehensive screening protocols to mitigate the increased cancer risk associated with ART.