The significant impact of Parkinson disease on sleep was clearly noted in James Parkinson’s remarkable description of the illness in his 1817 monograph, “An Essay on the Shaking Palsy.” He correctly noted that the motoric symptoms of Parkinson disease, such as severe nocturnal emergent tremor or nocturnal immobility, have great potential to interrupt sleep. Today, we are aware that the sleep-Parkinson disease interaction takes many other forms, including the effect of Parkinson drugs or Parkinson-associated behavioral symptoms (depression and psychosis) on sleep, and the (mostly beneficial) effect of sleep on the symptoms of the disease. The authors highlight the common sleep disorders found in Parkinson disease, looking at both the potential etiologies and treatment options. One of the most striking sleep problems in Parkinson disease is excessive daytime sleepiness, which is in part due to medication side effects, but also highly correlated with age and duration of disease. We have also learned that many sleep disorders that are moderately common in the general population, such as restless legs syndrome and REM sleep behavior disorder, are even more prevalent among Parkinson patients, the latter condition sometimes antedating clinical Parkinson disease by years. Finally, this update discusses the role of circadian disruption in the development of Parkinson disease, an exciting new area of research and potential intervention.