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

How far is O'Fallon, Illinois from Portsmouth, Ohio?

The distance from O'Fallon, Illinois to Portsmouth, Ohio is 373 miles (600.3 km) as the crow flies. Portsmouth, Ohio is located E of O'Fallon, Illinois. By car, the driving distance is approximately 447.6 miles, taking about 9h 0min. A direct flight would take roughly 1h 15min. Both are located in United States — O'Fallon, Illinois in Illinois and Portsmouth, Ohio in Ohio.

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 O'Fallon, Illinois and Portsmouth, Ohio. 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.