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. There's nothing like the smell of a brand new house, and in O'Fallon, you'll find that a large proportion of houses were recently built. New growth in residential real estate is an indication that people are choosing to move to O'Fallon, and putting down their money on brand new construction. O'Fallon’s real estate is, on average, some of the newest in the nation. O'Fallon does seem to be experiencing an influx of affluent people, because 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.

Telecommuters are a relatively large percentage of the workforce: 13.95% of people work from home. While this number may seem small overall, as a fraction of the total workforce it is high relative to the nation. 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 very good place for families to consider. With an enviable combination of good schools, low crime, college-educated neighbors who tend to support education because of their own experiences, and a high rate of home ownership in predominantly single-family properties, O'Fallon really has some of the features that families look for when choosing a good community to raise children. Is O'Fallon perfect? Of course not, and if you like frenetic nightlife, it will be far from your cup of tea. But overall this is a solid community, with many things to recommend it as a family-friendly place to live.

The city of O'Fallon is a decent size, but despite this, it doesn't have a viable public transit system that people can use to get to work.

The citizens of O'Fallon are among the most well-educated in the nation: 42.41% of adults in O'Fallon have a bachelor's degree or even advanced degree, whereas the average US city has 21.84% holding at least a bachelor's degree.

The per capita income in O'Fallon in 2022 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.