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.

View of an actual South Dakota state highway sign. The signs enclose the route number within the state's shape on top of a green background.

Standard South Dakota state highway shields
System information
Notes	South Dakota highways are generally state-maintained.
Highway names
Interstates	Interstate X (I-X)
US Highways	U.S. Highway X (US X)
State	(State) Highway X (SD X)
System links
South Dakota State Trunk Highway System Interstate US State