New Underwood (Lakota: wóȟešma tȟéča;[5] "new undergrowth") is a city in Pennington County, South Dakota, United States.

According to the United States Census Bureau, the city has a total area of 1.00 square mile (2.59 km2), all land.

There were 280 housing units at an average density of 280.0 per square mile (108.1/km2).

28.6% of all households were made up of individuals, and 7.6% had someone living alone who was 65 years of age or older.

There were 265 housing units at an average density of 265.0 per square mile (102.3/km2).

The racial makeup of the city was 93.34% White, 5.84% Native American, and 0.81% from two or more races.

20.3% of all households were made up of individuals, and 11.6% had someone living alone who was 65 years of age or older.