Sleep is an essential human function, but many aspects of its regulation remain poorly understood. Adequate sleep is important for health and wellbeing, and variation in sleep quality, quantity and timing have been strongly associated with several human diseases and psychiatric disorders. Identifying genetic variants influencing sleep patterns will provide new insights into the molecular regulation of sleep in humans and help clarify the genetic contribution to causal links with disease. The recent availability of data from the UK Biobank has provided an unprecedented amount of data related to genetics, lifestyle factors and objective measures of activity through actigraphy data in 103,00 individuals. I will discuss the methods we have developed to estimate sleep-characteristics from the activity monior data in the UK Biobank and how we have used polysomnography data to validate our estimates. We have performed genome-wide analyses for these derived traits as well as a range of self-report sleep traits, and I will present the findings from these analyses and the new insights into the biology of sleep that we have gained.