Pea Ridge is a census-designated place in Shelby County, Alabama, United States. The community is named for Pea Ridge, the broadest ridge in the Cahaba Coal Field. This ridge divides the waters of the Cahaba River and Little Cahaba River. Pea Ridge has maintained a volunteer fire department since 1972. It was first named as a CDP in the 2020 Census which listed a population of 841.