O'Fallon is a larger medium-sized city located in the state of Missouri. With a population of 93,663 people and 22 associated neighborhoods, O'Fallon is the seventh largest community in Missouri. Much of the housing stock in O'Fallon was built relatively recently. The construction of new real estate can often be taken as an indication that the local O'Fallon economy is robust, and that jobs or other amenities are attracting an influx of new residents. This seems to be the case in O'Fallon, where the median household income is $104,863.00.

O'Fallon real estate is some of the most expensive in Missouri, although O'Fallon house values don't compare to the most expensive real estate in the U.S.

Also of interest is that O'Fallon has more people living here who work in computers and math than 95% of the places in the US.

One interesting thing about the economy is that relatively large numbers of people worked from their home: 13.95% of the workforce. While this number may seem small overall, as a fraction of the total workforce this is high compared to the rest of the county. These workers are often telecommuters who work in knowledge-based, white-collar professions. For example, Silicon Valley has large numbers of people who telecommute. Other at-home workers may be self-employed people who operate small businesses out of their homes.

Because of many things, O'Fallon is a great place for families with children to consider. First of all, many other families with children live here, making O'Fallon a place where both parents and children are more likely to develop social ties with other families, as well as find family-oriented services and community. The city’s good public school district and large population of college-educated adults provide an environment conducive to academic values. With regard to real estate, O'Fallon has a high rate of owner-occupied single family homes, which tends to reflect stability in the local community. Finally, O'Fallon’s overall crime rate is lower than average for the country.

O'Fallon is a decent-sized city, yet no one gets to work using public transit, because the city has no real transit system.

O'Fallon is one of the most well-educated cities in the nation. 42.41% of adults in O'Fallon have at least a bachelor's degree. Compare that to the average community in America, which has just 21.84% with a bachelor's degree or higher.

The per capita income in O'Fallon in 2018 was $45,938, which is wealthy relative to Missouri and the nation. This equates to an annual income of $183,752 for a family of four.

O'Fallon is a somewhat ethnically-diverse city. The people who call O'Fallon home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of O'Fallon residents report their race to be White, followed by Black or African-American. Important ancestries of people in O'Fallon include German, Irish, English, Italian, and French.

The most common language spoken in O'Fallon is English. Other important languages spoken here include Spanish and Other Asian languages.