The blood–brain barrier (BBB), a highly specialized and selective interface, is essential for preserving the homeostasis of the central nervous system (CNS) but also presents a significant barrier to the efficient administration of medications for neurological conditions. The BBB limits the passage of most therapeutic drugs due to its tight junctions, efflux transporters, and regulated permeability. As a result, there are few therapy choices for ailments including brain tumors, Parkinson's disease, Alzheimer's disease, stroke, and other CNS-related disorders. Conventional drug delivery methods, such as altering pharmaceuticals chemically and using intrusive administration. Drug delivery technologies based on nanotechnology have been a viable way to get over BBB-related restrictions in recent years. This paper offers a thorough summary of methods for improving drug transport across the blood-brain barrier that are mediated by nanoparticles. The structural features, BBB penetration mechanisms, and therapeutic applications of a variety of nanocarrier systems—including liposomes, polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, polymeric micelles, dendrimers, inorganic nanoparticles, and biomimetic carriers like exosomes—are examined. Receptor-mediated transcytosis, surface modification techniques, and biomimetic designs that enhance targeting effectiveness and biocompatibility are given particular attention. Furthermore, the review highlights key applications of nanoparticle-based systems in the management of major neurological disorders while critically addressing existing safety concerns, translational challenges, and regulatory limitations. Overall, this article underscores the potential of nanocarrier-based platforms to revolutionize CNS drug delivery and emphasizes future perspectives aimed at improving clinical translation and therapeutic outcome.