Gold nanoparticle (AuNP)-mediated photothermal therapy (PTT) has emerged as a promising approach for cancer treatment, offering high precision, minimal invasiveness, and selective tumor ablation through localized hyperthermia. This review explores the fundamental principles of AuNP-mediated PTT, including the design of AuNPs, synthesis strategies, and surface modifications that enhance their biocompatibility and targeting efficiency. Additionally, the integration of AuNPs with other therapeutic modalities is also discussed, such as chemotherapy, radiotherapy, and immunotherapy, to achieve synergistic treatment outcomes. The theragnostic potential of AuNPs, combining diagnostic imaging with therapeutic applications, is also highlighted, emphasizing their role in personalized medicine. But, despite significant advancements, challenges such as biodistribution, long-term safety, and regulatory approval remain key barriers to clinical translation. Ongoing research is expected to refine AuNP-based PTT, paving the way for its widespread clinical application in cancer treatment.