O'Fallon City Hall is located at 255 South Lincoln Avenue, O'Fallon IL 62269; phone: 618-624-4508.
The O'Fallon area was originally settled by Captain Joseph Ogle who settled in Prairie Ridge in 1802. The City was named after Colonel John O'Fallon who was a wealthy gentleman from St. Louis. He had an interest in the Ohio and Mississippi Railroad, which built a depot and water tower in 1854 in what is the present location of the City of O'Fallon. In that same year, town lots were platted by Ernest Tiedemann, with the first lots being sold on May 13, 1854 for up to $10.00 each. O'Fallon was incorporated as a Village on January 27, 1874, however, a referendum held on March 14, 1905 changed its structure to a City form of government.
The City of O'Fallon has evolved from its early rural railroad and mining beginnings to its present state as a fast growing suburban activity center. This has received considerable momentum since the opening of the St. Clair Square Mall. This transition continues today as office and employment centers are being developed in and around the city. Previously, citizens residing in O'Fallon commuted to work at Scott Air Force Base, Belleville, and downtown St. Louis. While this pattern still occurs, O'Fallon is increasingly becoming an employment center itself O'Fallon, Illinois and is experiencing an increased share of regional office and retail activity. Development of Central Park Plaza, Regency Park, Wal-Mart, Sam's, St. Clair Auto Mall, and Eagle Center exemplifies this trend. The major force behind this change has been Interstate 64, which is becoming increasingly attractive as a development corridor. The factors influencing O'Fallon's growth include: a fifteen minute drive to downtown St. Louis, "build-out" that is occurring in the western suburbs, a strong regional and national economy, highly regarded school systems, small town scale and atmosphere, and attractive residential neighborhoods.