De Amerikaanse staat South Dakota is onderverdeeld in 66 county's.
400px|right|thumb|County's van South Dakota
CountyInwonersU.S. Census Bureau: Annual Estimates of the Population for Counties: April 1, 2000 to July 1, 20071 juli 2007HoofdplaatsInwonersU.S. Census Bureau: Population Estimates for All Places: 2000 to 20071 juli 2007Aurora2854Plankinton560Beadle15.669Huron10.902Bennett3441Martin1010Bon Homme7071Tyndall117Brookings29.241Brookings19.463Brown35.113Aberdeen24.410Brule5190Chamberlain2258Buffalo2111Gann Valley---Butte9475Belle Fourche4909Campbell1397Mound City66Charles Mix8953Lake Andes761Clark3472Clark1073Clay13.364Vermillion10.251Codington26.356Watertown20.530Corson4205McIntosh209Custer7818Custer1902Davison19.020Mitchell14.832Day5667Webster1718Deuel4259Clear Lake1222Dewey6005Timber Lake426Douglas3018Armour671Edmunds4008Ipswich862Fall River7210Hot Springs4052Faulk2276Faulkton672Grant7159Milbank3237Gregory4110Burke576Haakon1845Philip741Hamlin5621Hayti351Hand3273Miller1341Hanson3621Alexandria653Harding1180Buffalo330Hughes16.880Pierre14.032Hutchinson7340Olivet64Hyde1465Highmore736Jackson2792Kadoka653Jerauld1993Wessington Springs853Jones1055Murdo542Kingsbury5394De Smet1055Lake11.372Madison6319Lawrence23.347Deadwood1293Lincoln37.765Canton4127Lyman3909Kennebec284Marshall4318Britton1264McCook5755Salem1345McPherson2496Leola390Meade23.999Sturgis5990Mellette2019White River563Miner2475Howard909Minnehaha175.272Sioux Falls151.505Moody6506Flandreau2263Oglala Lakota13.589Hot SpringsOglala Lakota County en Todd County hebben geen hoofdplaats, de bestuurlijke taken worden uitgevoerd in de hoofdplaatsen van de naburige county's, respectievelijk Fall River County en Tripp County.4052Pennington96.280Rapid City63.997Perkins2917Bison328Potter2184Gettysburg1088Roberts9865Sisseton2457Sanborn2444Woonsocket642Spink6739Redfield2290Stanley2787Fort Pierre2068Sully1411Onida647Todd10.157Winner2805Tripp5806Winner2805Turner8379Parker980Union13.952Elk Point1888Walworth5262Selby660Yankton21.645Yankton13.643Ziebach2643Dupree452
South Dakota