Lost Springs is a city in Marion County, Kansas, United States. As of the 2020 census, the population of the city was 55. The city was named for a nearby lost spring that was a camping spot along the 19th century Santa Fe Trail. It is located south of Herington, about 0.6 miles west of the intersection of U.S. Route 77 highway and 340th Street next to the Union Pacific Railroad.

Marion County is a county located in the U.S. state of Kansas. Its county seat is Marion and its most populous city is Hillsboro. As of the 2020 census, the county population was 11,823. The county was named in honor of Francis Marion, a brigadier general of the American Revolutionary War, known as the "Swamp Fox".