Nemo is an unincorporated community in Lawrence County, South Dakota, United States. The population was 546 at the 2010 census. Nemo has been assigned the ZIP code of 57759.According to the Federal Writers' Project, the origin of the name Nemo is obscure.As of the census of 2010, there were 546 people, 164 households, and 109 families in the town. There were 260 housing units. The racial makeup of the town was 81.7% White, 3.3% African American, 11.7% Native American, 0.4% Asian, 0.2% Pacific Islander, 0.9% from other races, and 1.8% from two or more races. Hispanic or Latino of any race were 4.4% of the population.There were 164 households of which 14.0% had children under the age of 18 living with them, 63.4% were married couples living together, 0.6% had a female householder with no husband present, 2.4% had a male householder with no wife present, and 33.5% were non-families. 29.3% of all households were made up of individuals. The average household size was 2.