
This is a list of the National Register of Historic Places listings in Pennington County, South Dakota.
Pennington County is a county in the U.S. state of South Dakota. As of the 2010 United States Census, the population was 100,948, making it the second-most populous county in South Dakota. Its county seat is Rapid City. The county was created in 1875, and was organized in 1877. It is named for John L. Pennington, fifth Governor of Dakota Territory, who held office in 1875 when the county was formed.

The Gramberg Ranch, in Pennington County, South Dakota near Hermosa, was listed on the National Register of Historic Places in 1999. The listing included eight contributing buildings, six contributing structures, and four contributing sites.

The Keystone School, on 3rd St. in Keystone, South Dakota, was listed on the National Register of Historic Places in 1981.

KFXS is a radio station licensed to serve Rapid City, South Dakota. The station is owned by HomeSlice Media Group, LLC. It airs a classic rock music format.

KOUT is a radio station licensed to serve Rapid City, South Dakota. The station is owned by HomeSlice Media Group, LLC. It airs a country music format.

The Pennington County Sheriff's Office is the sheriff's office for Pennington County, South Dakota, U.S.. The current Sheriff is Kevin Thom. The sheriff's office provides county-wide law enforcement services to over 109,000 residents and visitors to the county. There are 118 deputies in the Patrol Division, in addition court services, investigations, and operation of the Pennington County Jail. The sheriff's office is headquartered in Rapid City. The sheriff's office issues concealed pistol permits to county residents.
The Wasta Rest Stop Tipi-Eastbound and Wasta Rest Stop Tipi-Westbound on Interstate 90 in Wasta, South Dakota were listed on the National Register of Historic Places in 2015.