Abstract: Neurological disorders are now among the leading causes of death, disability, and overall disease burden worldwide, making the development of effective preventive and therapeutic strategies a major global health priority. A central challenge in this field is the efficient delivery of bioactive agents across the blood-brain barrier (BBB), which severely restricts brain access for most exogenous compounds. Chitosan, a natural cationic polysaccharide, has attracted considerable interest because of its biocompatibility, biodegradability, mucoadhesive behavior, and facile chemical modifiability, all of which are advantageous for drug and nutrient delivery. In particular, chitosan-based nanoparticles, liposomes, and micelles have shown distinct potential for protecting bioactive compounds, enabling controlled or stimuli-responsive release, and improving BBB transport. This review systematically summarizes the design and fabrication strategies of chitosan-based nano-delivery systems, with emphasis on the structural features and delivery behaviors of nanoparticles, liposomes, and micelles, as well as their applications and potential mechanisms in neurological disorders, including Alzheimer’s disease, Parkinson’s disease, stroke, and brain tumors. These advances provide a useful foundation for the future development of functional foods and nutritional interventions targeting neurological diseases.