Newtown (formerly, Sailor Flat, Newton and Sailors Flat) is a former settlement in Nevada County, California. It lies at an elevation of 2113 feet (644 m). Newtown is located west of Nevada City.
Newtown was settled in 1850, but never grew very large; its 1855 population was 53. The Newtown area later became a farming district, particularly for the cultivation of pears.