The advancement of novel cancer therapies is critical to addressing the limitations of traditional treatments. Nanotechnology has emerged as a transformative approach, offering precision and efficiency in cancer treatment and diagnostics. This work explores the foundational principles of nanotechnology, emphasizing key nanomaterials and mechanisms for drug delivery. It delves into the application of nanotechnologies in cancer therapy, including targeted drug delivery, enhanced chemotherapy, immunotherapy, RNA-based treatments, and hyperthermia. Additionally, the study highlights advancements in cancer diagnostics, focusing on early detection, nanosensors, and imaging technologies. Despite its potential, the translation of nanotechnology into clinical practice faces significant challenges, including biocompatibility, safety concerns, and regulatory hurdles. Looking forward, personalized nanomedicine, combination therapies, and global accessibility present promising future directions. This discussion underscores nanotechnology’s pivotal role in revolutionizing cancer treatment while addressing critical barriers to its widespread adoption.