Ralls County Missouri has 9 places on the National Register of Historic Places including 2 places of National significance and 2 places of Statewide significance. Significant places include Lock and Dam No. 22 Historic District, Ralls County Courthouse and Jail-Sheriff's House, Garth, John, House and St. Paul Catholic Church and Brown, James B., House.
Some of the country's most noteable architects helped create the Ralls County places including Abbott, Edwin E., et al, USCOE, Father Francis Kielty, Martin Hogan, Kielty Francis M. and John Lankford. Prominent architectural styles found in Ralls Country are Gothic Revival, Greek Revival and Second Empire.