The 2004 South Dakota's at-large congressional district special election was held on July 12, 2004 to select the successor to Republican Representative Bill Janklow who resigned on July 11, 2004, following a conviction of vehicular manslaughter after an accident that had occurred months earlier, creating an open seat and necessitating a special election. Each party held a nominating convention to choose their nominee for the special election. Republicans selected state Senator over , also a member of the South Dakota State Senate, as their nominee while Democrats chose attorney Stephanie Herseth, who had unsuccessfully challenged Janklow in 2002.