Rapid Valley is a census-designated place (CDP) and unincorporated community in Pennington County, South Dakota, United States, and a suburb of Rapid City.

[5] Rapid Valley has been a retreat for people living in Rapid City due to its low crime, cheap land, and views of the Black Hills.

Rapid Valley is home to many industrial and financial businesses, and is the headquarters for many corporations specializing in transport and engineering.

According to the United States Census Bureau, the CDP has a total area of 10.1 square miles (26.3 km2), all land.

Rapid Valley is often portrayed as the ideal example of urban sprawl.