福尔里弗县（Fall River County, South Dakota）是美国南达科他州西南角的一个县，西邻怀俄明州，南邻内布拉斯加州。面积4,530平方公里。根据美国2000年人口普查，共有人口7,453人。县治温泉市 （Hot Springs）也是香农县的行政中心 （该县并无县治）。

县政府成立于1883年3月6日，曾名福赛斯县 （Forsythe County）。县名来自当地主要河流。

Fall River County is a county located in the U.S. state of South Dakota. As of the 2010 census, the population was 7,094. Its county seat is Hot Springs. The county was founded in 1883. It is named for Fall River which runs through it.