| St. Charles County is a county located in the U.S. state | | | | Hispanic or Latino of any race were 1.47% of the |
| of Missouri. As of 2000, the population was 283,883. | | | | population. |
| Saint Charles County is part of the St. Louis Metro | | | | There were 101,663 households out of which 40.50% |
| Area. Its county seat is Saint Charles6. The county | | | | had children under the age of 18 living with them, |
| was organized in 1812 and named for the Spanish | | | | 63.20% were married couples living together, 9.20% |
| district once located here, San Carlos, from Saint | | | | have a woman whose husband does not live with her, |
| Charles Borromeo. | | | | and 24.20% were non-families. 19.40% of all |
| Geography | | | | households were made up of individuals and 5.90% |
| The county has a total area of 1,534 km² (592 | | | | had someone living alone who was 65 years of age |
| mi²). 1,451 km² (560 mi²) of it is land and | | | | or older. The average household size was 2.76 and |
| 83 km² (32 mi²) of it (5.39%) is water. | | | | the average family size was 3.18. |
| Adjacent counties | | | | In the county the population was spread out with |
| Lincoln County (northwest) | | | | 29.00% under the age of 18, 8.20% from 18 to 24, |
| Calhoun County, Illinois (north) | | | | 32.60% from 25 to 44, 21.60% from 45 to 64, and |
| Jersey County, Illinois (northeast) | | | | 8.80% who were 65 years of age or older. The |
| Madison County, Illinois (east) | | | | median age was 34 years. For every 100 females |
| St. Louis County (southeast) | | | | there were 97.10 males. For every 100 females age 18 |
| Franklin County (south) | | | | and over, there were 94.10 males. |
| Warren County (west) | | | | The median income for a household in the county was |
| Major highways | | | | $57,258, and the median income for a family was |
| Interstate 64 | | | | $64,415. Males had a median income of $44,528 |
| Interstate 70 | | | | versus $29,405 for females. The per capita income |
| U.S. Route 40 | | | | for the county was $23,592. 4.00% of the population |
| U.S. Route 61 | | | | and 2.80% of families were below the poverty line. Out |
| U.S. Route 67 | | | | of the total people living in poverty, 4.90% are under |
| Route 79 | | | | the age of 18 and 5.10% are 65 or older. |
| Route 94 | | | | St. Charles County, with a population of 337,572, has |
| Route 364 | | | | been one of the fastest-growing counties in the |
| Route 370 | | | | country for decades, with 55 percent growth in the |
| Demographics | | | | 1980s, 33 percent in the 1990s, and another 13 percent |
| As of 2000, there were 283,883 people, 101,663 | | | | between 2000 and 2004. The county features a |
| households, and 77,060 families residing in the county. | | | | cross-section of industry, as well as extensive retail |
| The population density was 196/km² (507 | | | | and some agriculture. With the Missouri River on the |
| mi²). There were 105,514 housing units at an | | | | south and the Mississippi on the north and east, the |
| average density of 73 persons/km² (188 persons | | | | county is bisected east to west by Interstate 70. St. |
| mi²). The racial makeup of the county was | | | | Charles County has two small airports and two ferries |
| 94.67% White, 2.69% African American, 0.23% Native | | | | that cross the Mississippi River. The City of St. Charles |
| American, 0.85% Asian, 0.03% Pacific Islander, 0.46% | | | | is the county seat. |
| from other races, and 1.07% from two or more races. | | | | |