The advent of CRISPR/Cas9 genome editing has significantly transformed the landscape of cancer therapeutics by facilitating precise and programmable manipulation of disease-associated genetic modifications. This review comprehensively evaluates the current clinical and translational landscape of CRISPR/Cas9-based cancer therapies through an analysis of published literature and registered clinical trials. The current CRISPR/Cas9 applications in oncology are primarily centred on three mechanistic strategies: immune cell engineering for enhanced tumor recognition, direct targeting of oncogenic mutations, and modulation of tumor-supportive pathways. Analysis of 32 clinical trials indicates that CRISPR-based interventions have demonstrated encouraging safety profiles and early signs of clinical activity, particularly in ex vivo engineered immune-cell therapies. Notable examples include CRISPR-edited CAR-T cell products targeting CD19 and BCMA, which have achieved objective responses in relapsed or refractory hematological malignancies while demonstrating sustained persistence of edited cells in vivo. In contrast, clinical translation into solid tumors remains comparatively limited due to challenges associated with delivery efficiency, tumor heterogeneity, and the immunosuppressive tumor microenvironment. Technological advancements, including multiplex genome editing, base editing, and prime editing have expanded the precision and versatility of CRISPR-based interventions, while integration with immunotherapy and nanotechnology-based delivery systems continues to broaden therapeutic potential. Despite these advances, several significant challenges still need to be addressed, including off-target editing, manufacturing scalability, delivery limitations, and regulatory considerations. Overall, CRISPR/Cas9 represents a promising yet evolving platform in oncology, with its future clinical success dependent on achieving a balance between precision, safety, scalability, and long-term therapeutic durability.