St. Charles County is named for St. Charles Borromeo, who was an Italian saint and cardinal of the Roman Catholic Church.
Surrounding County Courthouses:
N – Lincoln County, Calhoun County, Illinois and Jersey County, Illinois
E – Madison County, Illinois
S – St. Louis County and Franklin County
W – Warren County
Created: October 1, 1812 
County Seat:
St. Charles 1812 – present
Old County Courthouse – St. Charles
Location: 100 North 3rd Street / Jefferson Street
Built: 1900– 1903
Style: Classical Revival
Architect: Jerome Bibb Legg of St. Louis
Contractor: Nicholas Pelligreen of St. Louis and J W Thompson
Description: The building faces east and is a three story Carthage and Bedford stone structure. The building sits on the crest of Clerks Hill. The east front has a portico with three arches on the first story and four columns rising from the second story to the top of the third story and with a large header above at the roof line. A similar portico is on the west side.
See: The architect, Jerome Bibb Legg of St. Louis, Missouri, also designed the courthouse in Ballard County, Kentucky and Gasconade County, Shelby County and Ste. Genevieve County, Missouri.
Note: The previous courthouse was designed and constructed by Solomon Jenkins in 1846 at a cost of $9,000.. J W Thompson constructed the foundation, walls and roof for the present courthouse at a cost of $37,349, and Nicholas Pelligreen completed the building at a cost of $57,000.
County Courthouse – St. Charles
Location: 100 North 2nd Street / Jefferson Street
Built: 1992– 1993
Style: Modern
Architect: Sverdrup CRSS, a division of Jacobs Facilities Inc. of St. Louis.
Contractor: Sverdrup CRSS, a division of Jacobs Facilities Inc. of St. Louis.
Description: The building faces southwest and is a five story red colored brick, stone and concrete structure. The southwest front has a semi-circular glass and stone one story entrance. Behind rises a semi-circular section with extended roof overhang. The fifth story is recessed with similar overhang. The south side has red colored brick facing and vertical windows and the west side has red colored brick facing on the lower section.
County Justice Center – St. Charles
Location: 301 North 2nd Street / Monroe Street
Built: 1987– 1988
Style: Modern
Architect: Harry C LePique & Associates and Powers Associates Inc.
Contractor: Hankins Construction Company.
Description: The building faces east and is a four story red colored brick, stone and concrete structure. The building has small windows and descends down a slope. A horizontal band of stone runs along the top of the first story. The central entrance on the east side is recessed. The roof line is flat.
See: The 19th Judicial District covers St. Charles County.
County Administration – St. Charles
Location: 201 North 2nd Street / Monroe Street
Built: 1993– 1994
Style: Modern
Architect: JSverdrup CRSS, a division of Jacobs Facilities Inc. of St. Louis.
Contractor: Sverdrup CRSS, a division of Jacobs Facilities Inc. of St. Louis.
Description: The building faces east and is a five story concrete and glass structure. The east front is rounded with columns rising to the roof line and glass windows between.
Old County Courthouse – St. Charles
County Courthouse – St. Charles
County Justice Center – St. Charles
County Administration – St. Charles
Photos taken 2009