Boulder to O'Fallon, Missouri: Road Trip Guide & Distance

How far is Boulder from O'Fallon, Missouri?

The distance from Boulder to O'Fallon, Missouri is 781.4 miles (1257.5 km) as the crow flies. O'Fallon, Missouri is located E of Boulder. By car, the driving distance is approximately 937.6 miles, taking about 18h 52min. A direct flight would take roughly 2h 4min. Both are located in United States — Boulder in Colorado and O'Fallon, Missouri in Missouri.

This is a serious multi-day road trip! We strongly recommend breaking this journey up with an overnight stay to ensure you arrive safely and refreshed. Heading East means you'll be driving into the sunrise if you start early. Keep your windshield clean for the best visibility. For a trip of this distance, flying is significantly faster. However, driving offers the flexibility to explore stops along the way.

Coordinates come from public place data for Boulder and O'Fallon, Missouri. 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.