This review systematically examines the IL-17A-mediated neuro-inflammatory cascades; the mechanistic contributions to neurodegenerative pathology in the established disease models including multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis; and current therapeutic strategies targeting the IL-17A signaling pathways. Here, IL17A is linked to early-onset autosomal dominant Alzheimer disease.