How far is Unionville, MO from O'Fallon, MO?
The driving distance from Unionville, MO to O'Fallon, MO is about 227 miles (365.4 km), with a travel time of about 03h 38m by car.
- The straight-line flight distance is about 168.1 miles (270.6 km).
- For a round trip, plan for roughly 07h 16m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 8:00 AM CDT.
Reverse, save, or send this route
This drive is better planned with a longer stop or an overnight stay. Copy the route link, send it to another device, or print a clean version before you head out.
This drive is better planned with a longer stop or an overnight stay.
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 03h 38m.
An early departure helps you fit a real stop into the day without turning the return into a late-night drive.
This departure sits inside the recommended comfort window for the route.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
City in Shelby County, Missouri
Route Weather Snapshot
Check the forecast at both ends before you head out.
Showers And Thunderstorms Likely
Partly Sunny
Driving Route Map
The map below follows the saved road route between Unionville and O'Fallon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Unionville and O'Fallon.
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1
Start on Main Street
24.5 mi · 36 min · Main Street
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2
At the end of the road, turn right
54.5 mi · 1 hr 5 min
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3
Take the exit left toward US 36 East, MO 110 East: Hannibal
929 ft · 12 sec
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4
Merge slight left onto Chicago-Kansas City Expressway
52.9 mi · 1 hr 1 min · Chicago-Kansas City Expressway
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5
Continue on V.F.W. Memorial Highway
5.8 mi · 7 min · V.F.W. Memorial Highway
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6
Take the exit slight right toward Veterans Road
1167 ft · 30 sec
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7
Turn right onto Veterans Road
2.1 mi · 4 min · Veterans Road
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8
At the end of the road, turn left onto County Road 422
85 m · 7 sec · County Road 422
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9
Continue on Paris Gravel Road
2539 ft · 1 min · Paris Gravel Road
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10
Take the ramp right
37 m · 3 sec
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11
Merge slight left onto Avenue of the Saints
73.7 mi · 1 hr 27 min · Avenue of the Saints
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12
Take the exit slight left toward I 70 East: Saint Louis
2705 ft · 51 sec
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13
Merge slight left onto Dwight D Eisenhower Highway
6.4 mi · 8 min · Dwight D Eisenhower Highway
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14
Take the exit slight right toward MO K: O'Fallon
1765 ft · 43 sec
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15
Turn straight onto Drennen Parkway
46 m · 3 sec · Drennen Parkway
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16
Keep slight right to continue on Drennen Parkway
51 m · 6 sec · Drennen Parkway
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17
Turn slight left onto MO K: O'Fallon
19 m · 3 sec
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18
Continue on South Main Street
3115 ft · 2 min · South Main Street
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19
Turn right
8 m · 2 sec
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20
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Unionville and O'Fallon.
Interchange-aware route
The drive includes several ramps, exits, or merges, so checking the next few maneuvers before busy interchanges is useful.
Avenue of the Saints
Merge slight left onto Avenue of the Saints
73.7 mi · 01h 27m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A longer out-and-back drive
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
Showers And Thunderstorms Likely leaving Unionville and Partly Sunny near O'Fallon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Unionville to O'Fallon?
The road trip is about 227 miles (365.4 km) and usually takes 03h 38m in normal driving conditions.
Is this a same-day trip or an overnight route?
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
What is the halfway point on this route?
Hunnewell is a useful midpoint, sitting about 111.2 miles from Unionville and 115.9 miles from O'Fallon.
How much longer is the road route than the straight-line distance?
The direct path is about 168.1 miles (270.6 km), while the road route adds roughly 58.9 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 6:00 AM to 8:00 AM CDT. If you want a more comfortable same-day return, try to leave by 9:44 AM CDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $30.21 one way or $60.41 round trip. Estimated CO2 is about 71.2 kg one way.
What should you check before leaving?
Before you leave, expect Showers And Thunderstorms Likely around Unionville and Partly Sunny near O'Fallon.
Stop Ideas Near Hunnewell
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 Hunnewell.
Quincy
La Plata
Hermann
Fort Madison station
Flight Path Map
This map shows the direct air route between Unionville and O'Fallon. Straight-line distance: 168.14 mi (270.59 km).
#1 Unionville
City in Putnam County, Missouri, United States
| Population | 1,733 |
| Coordinates | 40.4769600, -93.0032600 |
| Altitude | 324 |
| 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: 365 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 07h 33m |
| 40 mph (64.37 km/h) | 05h 40m |
| 50 mph (80.47 km/h) | 04h 32m |
| 60 mph (96.56 km/h) | 03h 47m |
| 70 mph (112.65 km/h) | 03h 14m |
| 80 mph (129 km/h) | 02h 49m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $30.21 | $60.41 |
| Mid-grade | $4.25 | $34.07 | $68.13 |
| Premium | $4.65 | $37.28 | $74.56 |
| Diesel | $5.30 | $42.49 | $84.97 |
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 · May 30, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.