KFJB was founded by Earl N. Peak, who was president of Marshall Electric Company. KFJB began broadcasting in the spring of 1922 as an experimental amateur radio station. The station claims to be the first radio station in the country to remotely broadcast a high school football game. The station was three blocks away from Franklin Field and Peak was able to string a cable between the studio and the football field to facilitate the broadcast.
On June 2, 1923, the US Department of Commerce granted a commercial broadcast license to KFJB. The first transmitter was a meager 10 watts, but the station received reception reports from Canada and the Hawaiian Islands when conditions were right.
KFJB is one of the commercial stations in the US to have the same call letters for their entire broadcasting history. KFJB observed their 85th anniversary in 2008.