How far is Montgomery City, MO from O'Fallon, MO?
The driving distance from Montgomery City, MO to O'Fallon, MO is about 49.6 miles (79.8 km), with a travel time of about 00h 49m by car.
- The straight-line flight distance is about 44.8 miles (72.1 km).
- For a round trip, plan for roughly 01h 38m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 8:00 AM to 10:00 AM CDT.
Reverse, save, or send this route
This route works well as a day trip with time at the destination. Copy the route link, send it to another device, or print a clean version before you head out.
This route works well as a day trip with time at the destination.
Flight Distance
Driving Distance
Gas Cost Calculator
Leave and Arrive Planner
Pick a departure time to see your estimated arrival and same-day return window.
Drive time stays fixed at 00h 49m.
A morning start gives you useful time at the destination and keeps the return out of the late evening.
You are leaving earlier than the recommended window, which gives you extra margin for breaks and traffic.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
City in Warren County, Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Sunny
Driving Route Map
The map below follows the saved road route between Montgomery City and O'Fallon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Montgomery City and O'Fallon.
-
1
Start on East 2nd Street
12 m · 7 sec · East 2nd Street
-
2
Turn left onto North Sturgeon Street
6.1 mi · 9 min · North Sturgeon Street
-
3
Enter the roundabout and take exit 3 toward the route
68 m · 4 sec
-
4
Exit the roundabout
76 m · 4 sec
-
5
Turn straight
620 ft · 14 sec
-
6
Enter the roundabout and take exit 4 toward I 70 East, US 40 East: Saint Louis
158 m · 10 sec
-
7
Exit the roundabout onto I 70 East, US 40 East: Saint Louis
1168 ft · 15 sec
-
8
Merge slight left onto Dwight D. Eisenhower Highway
42.1 mi · 51 min · Dwight D. Eisenhower Highway
-
9
Take the exit slight right toward MO K: O'Fallon
1765 ft · 43 sec
-
10
Turn straight onto Drennen Parkway
46 m · 3 sec · Drennen Parkway
-
11
Keep slight right to continue on Drennen Parkway
51 m · 6 sec · Drennen Parkway
-
12
Turn slight left onto MO K: O'Fallon
19 m · 3 sec
-
13
Continue on South Main Street
3115 ft · 2 min · South Main Street
-
14
Turn right
8 m · 2 sec
-
15
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Montgomery City and O'Fallon.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
Dwight D. Eisenhower Highway
Merge slight left onto Dwight D. Eisenhower Highway
42.1 mi · 00h 51m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A comfortable day-trip route
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
Sunny leaving Montgomery City and Sunny near O'Fallon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Montgomery City to O'Fallon?
The road trip is about 49.6 miles (79.8 km) and usually takes 00h 49m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
What is the halfway point on this route?
Warrenton is a useful midpoint, sitting about 24.9 miles from Montgomery City and 24.7 miles from O'Fallon.
How much longer is the road route than the straight-line distance?
The direct path is about 44.8 miles (72.1 km), while the road route adds roughly 4.8 extra miles because roads do not follow the straight air line.
When is the best time to leave for this route?
A good departure window is usually 8:00 AM to 10:00 AM CDT. If you want a more comfortable same-day return, try to leave by 4:52 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $6.60 one way or $13.20 round trip. Estimated CO2 is about 15.6 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Montgomery City and Sunny near O'Fallon.
Stop Ideas Near Warrenton
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Warrenton City Animal Control
Moscow Mills City Hall
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Warrenton.
Hermann
Washington
Kirkwood
Gateway Transportation Center
Flight Path Map
This map shows the direct air route between Montgomery City and O'Fallon. Straight-line distance: 44.8 mi (72.1 km).
#1 Montgomery City
City in Missouri, United States
| Population | 2,678 |
| Coordinates | 38.9775400, -91.5048800 |
| Altitude | 251 |
| Country | United States |
#2 O'Fallon
The most populous city in St.
| Population | 89,769 |
| Coordinates | 38.8106100, -90.6998500 |
| Altitude | 165 |
| Country | United States |
End: (-90.699849, 38.810674)
Estimated Travel Time
Distance: 80 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 39m |
| 40 mph (64.37 km/h) | 01h 14m |
| 50 mph (80.47 km/h) | 00h 59m |
| 60 mph (96.56 km/h) | 00h 49m |
| 70 mph (112.65 km/h) | 00h 42m |
| 80 mph (129 km/h) | 00h 37m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $6.60 | $13.20 |
| Mid-grade | $4.25 | $7.44 | $14.89 |
| Premium | $4.65 | $8.14 | $16.29 |
| Diesel | $5.30 | $9.28 | $18.56 |
Assumes 8.3 L/100 km (about 28.3 MPG). CO2 is an estimate and varies by vehicle, fuel blend, traffic, and terrain.
Prices in Missouri · Apr 19, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.