Fort Walton Beach, often referred to by the initialism FWB, a city in southern Okaloosa County, Florida, United States. As of the 2020 U.S. census, the population was 20,922, up from 19,507 in 2010. It is the principal city of the Fort Walton Beach−Crestview−Destin Metropolitan Statistical Area.

Okaloosa County is located in the northwestern portion of the U.S. state of Florida, extending from the Gulf of Mexico to the Alabama state line. As of the 2020 census, the population was 211,668. Its county seat is Crestview. Okaloosa County is included in the Crestview-Fort Walton Beach-Destin, FL Metropolitan Statistical Area.