4.35% of the population for whom poverty status is determined in Castlewood, SD (35 out of 804 people) live below the poverty line, a number that is lower than the national average of 12.5%. The largest demographic living in poverty are Males 6 - 11, followed by Females 25 - 34 and then Females < 5.

The most common racial or ethnic group living below the poverty line in Castlewood, SD is White, followed by Other and Black.

The Census Bureau uses a set of money income thresholds that vary by family size and composition to determine who classifies as impoverished. If a family's total income is less than the family's threshold than that family and every individual in it is considered to be living in poverty.