Humphreys is a village in southwest Sullivan County, Missouri, United States. The population was 89 at the 2020 census. Humphreys is located in southwestern Sullivan County. The community is at the intersection of Missouri State Routes 6 and 139. The community of Galt is about four miles to the west in Grundy County. Medicine Creek flows past abou…Humphreys is a village in southwest Sullivan County, Missouri, United States. The population was 89 at the 2020 census. Humphreys is located in southwestern Sullivan County. The community is at the intersection of Missouri State Routes 6 and 139. The community of Galt is about four miles to the west in Grundy County. Medicine Creek flows past about three miles to the west and Muddy Creek flows past the east side of the community.