Ainsworth is a city in Brown County, Nebraska, United States. The population was 1,862 at the 2000 census. It is the county seat of Brown County.
Ainsworth is located at 42°32′51″N 99°51′32″W / 42.5475°N 99.85889°W / 42.5475; -99.85889 (42.547421, -99.859022).
According to the United States Census Bureau, the city has a total area of 1.0 square miles (2.6 km²), all of it land.