Ainsworth is a city and county seat of Brown County, Nebraska, United States. The population was 1,728 at the 2010 census.
Ainsworth was platted in 1883 when the railroad was extended to that point. It was named for James E. Ainsworth, a railroad engineer who was instrumental in building the railroad through Brown County. Ainsworth was incorporated as a village in December 1883.
Ainsworth is located at 42°32′51″N 99°51′32″W (42.547421, -99.859022). According to the United States Census Bureau, the city has a total area of 1.00 square mile (2.59 km2), all land.
The climate in this area is characterized by hot, humid summers and generally cool to cold winters. According to the Köppen Climate Classification system, Ainsworth has a humid continental climate, abbreviated "Dfa" on climate maps.
As of the census of 2010, there were 1,728 people, 804 households, and 450 families living in the city. The population density was 1,728.0 inhabitants per square mile (667.2/km2). There were 961 housing units at an average density of 961.0 per square mile (371.0/km2).