Langford is a town in Marshall County, South Dakota, United States. The population was 283 at the 2020 census. Langford was laid out in 188…Langford is a town in Marshall County, South Dakota, United States. The population was 283 at the 2020 census. Langford was laid out in 1886, and named in honor of Sam Langford, the original owner of the town site.