List of state highways in South Dakota

South Dakota's state highways were assigned in a numbering pattern that followed that of the U.S. Highways followed upon their inception. East-west highways carried even numbers and increased from north to south – while north-south highways carried odd numbers and increased from east to west. This holds true only for two-digit highways. Three-digit highways follow the odd–even routing, but do not sequentially remain near a "parent" route as a spur or alternate route, instead being more independent of any parent two-digit route.

The Bureau of Indian Affairs maintains a set of routes within the reservations of western South Dakota – using the standard BIA shield on green background.