Aumsville is a city in Marion County, Oregon, United States. The population was 4,234 at the 2020 census. It is part of the Salem Metr…Aumsville is a city in Marion County, Oregon, United States. The population was 4,234 at the 2020 census. It is part of the Salem Metropolitan Statistical Area. Aumsville is on the site of the pioneer farm of Henry L. Turner, who named the settlement for his son-in-law, Amos M. Davis, more familiarly known as "Aumus", who had died on December 23, 1863. Aumsville was incorporated on August 3, 1911.