The circadian clock controls daily rhythms in animal physiology, metabolism, and behavior, such as the sleep-wake cycle. Disruption of circadian rhythms has been revealed in many diseases including neurodegenerative disorders. Interestingly, patients with many neurodegenerative diseases often show problems with circadian clocks even years before other symptoms develop. Here we review the recent studies identifying the association between circadian rhythms and several major neurodegenerative disorders. Early intervention of circadian rhythms may benefit the treatment of neurodegeneration.