A ketogenic diet(KD) refers to an eating pattern designed to achieve a low-calorie content, minimum carbohydrate intake, high-fat consumption, and standard protein levels. A ketogenic diet is used in clinical practice to treat conditions including heart disease, diabetes, obesity, autism, glioblastoma, and other cancers. Although a ketogenic diet has not been recommended for any neurological disorders except epilepsy, extensive recent research suggests that such a diet may have a neuroprotective effect and may thus represent a new dietary therapy for the treatment of Parkinson’s disease(PD). In this review, we discuss in detail the mechanisms responsible for the neuroprotective effects of a ketogenic diet in Parkinson’s disease, with the aim of providing references for future clinical and experimental studies.