Waterloo is a village in Douglas County, Nebraska, United States. The population was 935 at the 2020 census. Waterloo was founded by Elias Kelsey and John Logan in 1883 after two failed attempts at incorporation. In 1870, the Union Pacific Railroad designated a stop at the location. The name possibly commemorates the Battle of Waterloo or Kelsey's birt…Waterloo is a village in Douglas County, Nebraska, United States. The population was 935 at the 2020 census. Waterloo was founded by Elias Kelsey and John Logan in 1883 after two failed attempts at incorporation. In 1870, the Union Pacific Railroad designated a stop at the location. The name possibly commemorates the Battle of Waterloo or Kelsey's birthplace Waterloo, New York.