Neurological disorders, particularly neurodegenerative diseases, pose significant therapeutic challenges due to the limited regenerative capacity of the central nervous system (CNS) and the restrictive nature of brain barriers that obstruct drug delivery. Stem cell-based therapies present a promising approach for neuronal regeneration, neuroprotection, and disease modification. This chapter explores the developmental origins of neurons and glial cells, establishing a foundation for understanding regenerative strategies. It also includes a thorough review of clinical trials examining stem cell therapies for amyotrophic lateral sclerosis (ALS), Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, stroke, and macular degeneration. While numerous phase I/II trials affirm the safety of mesenchymal stem cells (MSCs), neural progenitor cells, and neurons derived from embryonic stem cells, their long-term effectiveness remains uncertain. Key challenges—including immune rejection, limited stem cell survival, and the challenging blood-brain barrier—hinder clinical translation. Nonetheless, advancements in stem cell engineering, biomaterials, and targeted delivery methods provide promising strategies to address these obstacles. This chapter underscores the need for further research and optimization to fully realize the therapeutic potential of stem cell-based treatments for neurological diseases.