Cancer remains one of the leading causes of mortality worldwide, with conventional chemotherapy facing significant limitations including poor selectivity, systemic toxicity, and drug resistance. Nanoparticle-based drug delivery systems have emerged as a revolutionary approach to overcome these challenges, offering enhanced drug targeting, controlled release, and reduced side effects. This comprehensive review examines the current state of nanotechnology in cancer therapeutics, including various types of nanocarriers such as liposomes, polymeric nanoparticles, dendrimers, carbon nanotubes, and inorganic nanoparticles. The review discusses targeting strategies including passive targeting through the enhanced permeability and retention (EPR) effect and active targeting using ligand-receptor interactions. Clinical applications and FDA-approved nanomedicines are analyzed, along with recent advances in stimuli-responsive drug delivery systems. Despite promising results, challenges including manufacturing scalability, regulatory approval, and potential toxicity concerns remain. Future directions focus on personalized nanomedicine, combination therapies, and advanced targeting mechanisms. The integration of artificial intelligence and machine learning in nanoparticle design represents an emerging frontier with significant potential for improving therapeutic outcomes in cancer treatment.