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Cheap flights from St. Louis to Decatur from $349

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Decatur departing on 8/19. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Find the cheapest flights from St. Louis to Decatur

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
1:08 pm - 5:51 pmSTL  Lambert-St Louis-DEC Decatur Arpt
4h 43m1 stop Chicago O'Hare Intl
United Airlines Logo
6:55 pm - 11:09 pmDEC  Decatur Arpt-STL Lambert-St Louis
4h 14m1 stop Chicago O'Hare Intl
$354United Airlines
Sat, Jan 30 - Mon, Feb 1
United Airlines Logo
1:08 pm - 5:51 pmSTL  Lambert-St Louis-DEC Decatur Arpt
4h 43m1 stop Chicago O'Hare Intl
United Airlines Logo
6:55 pm - 6:06 pmDEC  Decatur Arpt-STL Lambert-St Louis
23h 11m1 stop Chicago O'Hare Intl
$361United Airlines
Sat, Jan 30 - Mon, Feb 1
United Airlines Logo
12:59 pm - 5:59 pmSTL  Lambert-St Louis-DEC Decatur Arpt
5h 00m1 stop Chicago O'Hare Intl
United Airlines Logo
9:12 am - 3:38 pmDEC  Decatur Arpt-STL Lambert-St Louis
6h 26m1 stop Chicago O'Hare Intl
$379United Airlines
Tue, Sep 1 - Mon, Sep 7
United Airlines Logo
8:00 am - 6:43 pmSTL  Lambert-St Louis-DEC Decatur Arpt
10h 43m1 stop Chicago O'Hare Intl
United Airlines Logo
9:12 am - 9:21 pmDEC  Decatur Arpt-STL Lambert-St Louis
12h 09m1 stop Chicago O'Hare Intl
$400United Airlines
Wed, Oct 14 - Thu, Oct 15
United Airlines Logo
5:30 pm - 5:59 pmSTL  Lambert-St Louis-DEC Decatur Arpt
24h 29m1 stop Chicago O'Hare Intl
United Airlines Logo
7:20 pm - 3:43 pmDEC  Decatur Arpt-STL Lambert-St Louis
20h 23m1 stop Chicago O'Hare Intl
$417United Airlines
Fri, Sep 4 - Fri, Sep 11
United Airlines Logo
12:59 pm - 6:44 pmSTL  Lambert-St Louis-DEC Decatur Arpt
5h 45m1 stop Chicago O'Hare Intl
United Airlines Logo
9:12 am - 2:17 pmDEC  Decatur Arpt-STL Lambert-St Louis
5h 05m1 stop Chicago O'Hare Intl
$462United Airlines
Tue, Sep 22 - Thu, Sep 24
United Airlines Logo
12:59 pm - 6:44 pmSTL  Lambert-St Louis-DEC Decatur Arpt
5h 45m1 stop Chicago O'Hare Intl
United Airlines Logo
7:20 pm - 10:59 pmDEC  Decatur Arpt-STL Lambert-St Louis
3h 39m1 stop Chicago O'Hare Intl
$528United Airlines
Fri, Sep 18 - Mon, Sep 21
United Airlines Logo
12:59 pm - 6:44 pmSTL  Lambert-St Louis-DEC Decatur Arpt
5h 45m1 stop Chicago O'Hare Intl
United Airlines Logo
7:20 pm - 10:59 pmDEC  Decatur Arpt-STL Lambert-St Louis
3h 39m1 stop Chicago O'Hare Intl
$553United Airlines
Fri, Sep 18 - Mon, Sep 21

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United Airlines flights from St. Louis to Decatur, Illinois

Our best United Airlines deals on St. Louis to Decatur, Illinois flight tickets
United Airlines
Jan 30
STL1:08 pmLambert-St Louis
4h 43m
1 stop
DEC5:51 pmDecatur Arpt
Feb 1
DEC6:55 pmDecatur Arpt
4h 14m
1 stop
STL11:09 pmLambert-St Louis
$354
United Airlines
Jan 30
STL1:08 pmLambert-St Louis
4h 43m
1 stop
DEC5:51 pmDecatur Arpt
Feb 1
DEC6:55 pmDecatur Arpt
23h 11m
1 stop
STL6:06 pmLambert-St Louis
$361
United Airlines
Sep 1
STL12:59 pmLambert-St Louis
5h 00m
1 stop
DEC5:59 pmDecatur Arpt
Sep 7
DEC9:12 amDecatur Arpt
6h 26m
1 stop
STL3:38 pmLambert-St Louis
$379

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Decatur, Illinois that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated August 10, 2026.
Use the filters below to find and compare flights from St. Louis to Decatur, Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Sat 1/30

1:08 pm-5:51 pm

1 stop4h 43m

Decatur Arpt

Mon 2/1

6:55 pm-11:09 pm

1 stop4h 14m

$354

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Sat 1/30

1:08 pm-5:51 pm

1 stop4h 43m

Decatur Arpt

Mon 2/1

6:55 pm-6:06 pm

1 stop23h 11m

$361

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Tue 9/1

12:59 pm-5:59 pm

1 stop5h 00m

Decatur Arpt

Mon 9/7

9:12 am-3:38 pm

1 stop6h 26m

$379

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Wed 10/14

8:00 am-6:43 pm

1 stop10h 43m

Decatur Arpt

Thu 10/15

9:12 am-9:21 pm

1 stop12h 09m

$400

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Fri 9/4

5:30 pm-5:59 pm

1 stop24h 29m

Decatur Arpt

Fri 9/11

7:20 pm-3:43 pm

1 stop20h 23m

$417

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Tue 9/22

12:59 pm-6:44 pm

1 stop5h 45m

Decatur Arpt

Thu 9/24

9:12 am-2:17 pm

1 stop5h 05m

$462

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Fri 9/18

12:59 pm-6:44 pm

1 stop5h 45m

Decatur Arpt

Mon 9/21

7:20 pm-10:59 pm

1 stop3h 39m

$528

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Fri 9/18

12:59 pm-6:44 pm

1 stop5h 45m

Decatur Arpt

Mon 9/21

7:20 pm-10:59 pm

1 stop3h 39m

$553
Cheapest one-way
Quickest one-way

St. LouisDecatur

STL Lambert-St Louis - DEC Decatur Arpt

STLDEC

Lambert-St Louis

Wed 8/19

12:59 pm-5:59 pm

1 stop5h 00m

$349

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to Decatur from

How to get the cheapest flight ticket from St. Louis to Decatur, Illinois

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest airline that flies from Lambert-St Louis to Decatur Arpt?

United Airlines is the most popular carrier operating from Lambert-St Louis to Decatur Arpt

When to book flights from St. Louis to Decatur, Illinois

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Decatur, Illinois according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Decatur, Illinois (STL to DEC) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Decatur, Illinois

Fastest flight time

4h 43m

Direct flights

None
The fastest flight from St. Louis to Decatur, Illinois takes 4h 43m
There are no direct flights from St. Louis to Decatur, Illinois. There are no popular flight routes from St. Louis to Decatur, Illinois.
Search flight deals

Frequently asked questions about flying from St. Louis to Decatur, Illinois

  • How far is Lambert-St Louis to Decatur Arpt by plane?

    The straight-line distance from Lambert-St Louis to Decatur Arpt is 106.9 mi. In terms of flight time, this usually takes a little over 4h 43m.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Decatur Arpt Airport?

    Prices for flights from Lambert-St Louis Airport to Decatur Arpt Airport were last updated today.

  • How old do you have to be to fly from Lambert-St Louis Airport to Decatur Arpt Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Decatur Arpt Airport.

  • What documentation or ID do you need to fly to Decatur Arpt Airport?

    The necessary travel and health documents for your Decatur Arpt Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Traveling to a place near Decatur?

Book flights to Decatur if you plan to visit one of these locations
Effingham
Mattoon
Forsyth

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Decatur?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Decatur from St. Louis.

Can I find flights from St. Louis to Decatur with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to Decatur from St. Louis with this policy.

How can momondo help me find flights from St. Louis to Decatur?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Decatur.

I’m not ready to book a flight from St. Louis to Decatur right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Decatur, momondo offers a useful price alert feature which will track prices for flights to Decatur from St. Louis and alert you when they change.

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