Denison to O'Fallon, Illinois: Road Trip Guide & Distance

How far is Denison from O'Fallon, Illinois?

The distance from Denison to O'Fallon, Illinois is 498 miles (801.4 km) as the crow flies. O'Fallon, Illinois is located NE of Denison. By car, the driving distance is approximately 597.6 miles, taking about 12h 1min. A direct flight would take roughly 1h 30min. Both are located in United States — Denison in Texas and O'Fallon, Illinois in Illinois.

This is a solid day of driving. Be sure to take breaks every 2-3 hours to avoid driver fatigue, and plan your meals ahead of time. Heading East means you'll be driving into the sunrise if you start early. Keep your windshield clean for the best visibility.

Coordinates come from public place data for Denison and O'Fallon, Illinois. The driving distance is estimated from straight-line distance with a road-factor model, so confirm the route in your navigation app. Fuel, flight, bus, and train values are planning estimates and can change by date, provider, road closures, and border rules.