KFUO is still owned and operated by its original owner, the Lutheran Church-Missouri Synod (LCMS).
In February 1923, the chairman of the LCMS' seminary board proposed a Lutheran radio station. The Lutheran Laymen's League, the Walther League, and students at the LCMS' Concordia Seminary raised the money for the station.
KFUO was licensed October 25, 1924, and went on the air December 14, 1924, sharing time with KSD. KSD's owner, the St. Louis Post-Dispatch, informed listeners that KSD would be silent at 546 meters (550 kHz) on Sunday and Thursday evenings.
For two months in October 1927, KFUO shared time instead with KFVE (later KWK) at 1280 kHz, but on November 20, 1927 was ordered again to share time with KSD. KFUO moved back on December 1, 1927.
Beginning in 1933, KSD tried to get fulltime use of 550 kHz by finding KFUO a different frequency.
In the middle of this controversy, St. Louis Star-Times publisher Elzey Roberts attempted to buy the station for $100,000, according to research by St. Louis media historian Frank Absher. The church turned down the offer. Roberts turned to Columbia where he bought station KFRU and subsequently put St. Louis station KXOK on the air.
Finally, in 1936, a hearing was held before the Federal Communications Commission. The next year, in July 1937, examiner P.W. Seward issued a recommendation that was the opposite of what KSD wanted, increasing KFUO's time on 550 from 26 to 60 hours per week.
KSD appealed to the FCC, the FCC reversed its examiner; then KFUO appealed to the U.S. Court of Appeals of the District of Columbia, which upheld the Commission on June 26, 1939.
Finally, on April 22, 1940, KFUO applied for limited-time operation on 830 kHz, a clear-channel dominated by KOA in Denver, Colorado. The FCC expedited the application and, on July 1, 1940, KFUO moved to 830.
In the March 29, 1941 reallocation of frequencies, KFUO moved to 850 kHz, still operating "limited time" from local sunrise to local sunset at Denver. The station is still one of the few remaining that operates in this manner.
In 1995, the NAACP challenged the license renewal of KFUO-AM/FM (the FM is a commercial classical music station) for lack of efforts in recruiting and hiring minority employees. In 1996, the FCC fined the stations and gave them a one-year renewal.
KFUO subsequently challenged the FCC's action in the U.S. Court of Appeals for the District of Columbia. The court not only overturned the FCC's fine, it threw out the Commission's 30-year-old affirmative action policies in a ruling on April 14, 1998. On September 16, the court refused to hear an appeal of its decision.
KFUO has for many years been the originating station for The Lutheran Hour. Dr. Walter Maier became the "voice" of the Lutheran Hour after he became known for his talks on KFUO. Do the call letters stand for a slogan? Frank Absher has found one reference in printed material about the station that read "Keep Forward-Upward-Onward!"