Nemo is an unincorporated community in Lawrence County, South Dakota, United States.

[2] According to the Federal Writers' Project, the origin of the name Nemo is obscure.

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.

39.5% of the population were below the poverty line, including 4.3% of those under age 18.

Nemo has a humid continental climate (Köppen Dfb).