How far is Sainte Genevieve County, MO from O'Fallon, MO?
The driving distance from Sainte Genevieve County, MO to O'Fallon, MO is about 86.2 miles (138.7 km), with a travel time of about 01h 27m by car.
- The straight-line flight distance is about 69 miles (111 km).
- For a round trip, plan for roughly 02h 54m 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 01h 27m.
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 Jefferson County, Missouri, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms
Chance Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between Sainte Genevieve County and O'Fallon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Sainte Genevieve County and O'Fallon.
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1
Start on the route
3020 ft · 2 min
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2
Turn right onto River Aux Vases Church Road
1.5 km · 4 min · River Aux Vases Church Road
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3
Turn right
6.9 mi · 10 min
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4
Take the ramp sharp left toward I 55 North: Saint Louis
1298 ft · 32 sec
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5
Merge slight left
44.6 mi · 48 min
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6
Continue on Rosa Parks Highway
1.3 mi · 2 min · Rosa Parks Highway
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7
Take the exit slight right toward I 270 West, I 255 East: Kansas City, Chicago
1279 ft · 27 sec
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8
Keep slight left to continue on I 270 West: Kansas City
118 m · 8 sec
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9
Continue on I 270 West
1.2 km · 1 min
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10
Merge slight left
18.1 mi · 23 min
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11
Take the exit slight right toward I 70: Kansas City, Saint Louis, Saint Louis Lambert International Airport
1 mi · 1 min
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12
Keep slight left to continue on I 70 West: Kansas City
645 ft · 11 sec
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13
Continue on I 70 West: Kansas City
1 km · 57 sec
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14
Merge slight left
13.6 mi · 17 min
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15
Take the exit slight right toward MO K: O'Fallon, Main Street
119 m · 8 sec
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16
Turn straight onto East Terra Lane
1.4 km · 2 min · East Terra Lane
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17
Turn right onto South Main Street
2830 ft · 1 min · South Main Street
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18
Turn right
8 m · 2 sec
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19
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Sainte Genevieve County 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.
I 55 North
Merge slight left
44.6 mi · 00h 48m
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.
Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms leaving Sainte Genevieve County and Chance Showers And Thunderstorms near O'Fallon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Sainte Genevieve County to O'Fallon?
The road trip is about 86.2 miles (138.7 km) and usually takes 01h 27m 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?
Kimmswick is a useful midpoint, sitting about 45.3 miles from Sainte Genevieve County and 40.8 miles from O'Fallon.
How much longer is the road route than the straight-line distance?
The direct path is about 69 miles (111 km), while the road route adds roughly 17.2 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 3:36 PM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $12.08 one way or $24.17 round trip. Estimated CO2 is about 27 kg one way.
What should you check before leaving?
Before you leave, expect Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms around Sainte Genevieve County and Chance Showers And Thunderstorms near O'Fallon.
Stop Ideas Near Kimmswick
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Kimmswick.
Kirkwood
Gateway Transportation Center
Washington
Alton
Flight Path Map
This map shows the direct air route between Sainte Genevieve County and O'Fallon. Straight-line distance: 68.97 mi (111 km).
#1 Sainte Genevieve County
County in Missouri, United States
| Population | 17,919 |
| Coordinates | 37.8944000, -90.1944200 |
| Altitude | 218 |
| 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: 139 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 02h 52m |
| 40 mph (64.37 km/h) | 02h 09m |
| 50 mph (80.47 km/h) | 01h 43m |
| 60 mph (96.56 km/h) | 01h 26m |
| 70 mph (112.65 km/h) | 01h 13m |
| 80 mph (129 km/h) | 01h 04m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.98 | $12.08 | $24.17 |
| Mid-grade | $4.34 | $13.20 | $26.39 |
| Premium | $4.71 | $14.31 | $28.62 |
| Diesel | $5.99 | $18.20 | $36.41 |
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 · Oct 15, 2026