Sleep is an eight-and-a-half hour concept album based around the neuroscience of sleep by German-British composer Max Richter. It was released on September 4, 2015, accompanied by a one-hour version with variations, From Sleep, later remixed as Sleep Remixes.

The documentary Max Richter's Sleep, directed by Natalie Johns, was released in April 2020 and focuses on Richter and Mahr's performances of Sleep in Los Angeles, Berlin, Sydney, and Paris. In March 2023, Richter released Sleep: Tranquility Base EP, with new versions of themes from Sleep. In January 2024, a "faded" edition of Sleep was released digitally. In March 2024, a digital Sleep: Piano Edition EP was released.