Bristol is a city located in western Day County, South Dakota, United States. It lies in Section 25 of Bristol Township, on the main line of what is now the BNSF Railway alongside U.S. Route 12. The population was 288 at the 2020 census.` Similar to many towns of the area and of the Midwest in general, Bristol came into being as a result of railroad expansion. The railroad, which first came through the area in the 1870s, identified the site which would become Bristol as Station#70. C.P.