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Cheap flights from St. Louis to Decatur from $335

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Decatur departing on 11/11. 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
9:23 am - 8:46 am
STL
-
DEC
23h 23m
1 stop
United Airlines Logo
6:55 pm - 12:34 am
DEC
-
STL
5h 39m
1 stop
$335United Airlines
Wed, Nov 11 - Sun, Nov 15
United Airlines Logo
9:40 am - 5:51 pm
STL
-
DEC
8h 11m
1 stop
United Airlines Logo
6:55 pm - 11:09 pm
DEC
-
STL
4h 14m
1 stop
$370United Airlines
Wed, Nov 11 - Sun, Nov 15
United Airlines Logo
8:33 am - 8:46 am
STL
-
DEC
24h 13m
1 stop
United Airlines Logo
6:55 pm - 11:09 pm
DEC
-
STL
4h 14m
1 stop
$374United Airlines
Wed, Nov 11 - Sun, Nov 15
United Airlines Logo
3:22 pm - 8:57 am
STL
-
DEC
17h 35m
1 stop
United Airlines Logo
6:45 pm - 11:29 pm
DEC
-
STL
4h 44m
1 stop
$468United Airlines
Sat, Jul 4 - Fri, Jul 10
United Airlines Logo
11:25 am - 5:56 pm
STL
-
DEC
6h 31m
1 stop
United Airlines Logo
6:45 pm - 11:29 pm
DEC
-
STL
4h 44m
1 stop
$484United Airlines
Sat, Aug 1 - Sat, Aug 8

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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
Nov 11
STL9:23 amLambert-St Louis
23h 23m
1 stop
DEC8:46 amDecatur Arpt
Nov 15
DEC6:55 pmDecatur Arpt
5h 39m
1 stop
STL12:34 amLambert-St Louis
$335
United Airlines
Nov 11
STL9:40 amLambert-St Louis
8h 11m
1 stop
DEC5:51 pmDecatur Arpt
Nov 15
DEC6:55 pmDecatur Arpt
4h 14m
1 stop
STL11:09 pmLambert-St Louis
$370
United Airlines
Nov 11
STL8:33 amLambert-St Louis
24h 13m
1 stop
DEC8:46 amDecatur Arpt
Nov 15
DEC6:55 pmDecatur Arpt
4h 14m
1 stop
STL11:09 pmLambert-St Louis
$374

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 June 21, 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

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Wed 11/11

9:23 am-8:46 am

1 stop23h 23m

Decatur Arpt

Sun 11/15

6:55 pm-12:34 am

1 stop5h 39m

$335

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Wed 11/11

9:40 am-5:51 pm

1 stop8h 11m

Decatur Arpt

Sun 11/15

6:55 pm-11:09 pm

1 stop4h 14m

$370

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Wed 11/11

8:33 am-8:46 am

1 stop24h 13m

Decatur Arpt

Sun 11/15

6:55 pm-11:09 pm

1 stop4h 14m

$374

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Sat 7/4

3:22 pm-8:57 am

1 stop17h 35m

Decatur Arpt

Fri 7/10

6:45 pm-11:29 pm

1 stop4h 44m

$468
Quickest round-trip

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Sat 8/1

11:25 am-5:56 pm

1 stop6h 31m

Decatur Arpt

Sat 8/8

6:45 pm-11:29 pm

1 stop4h 44m

$484

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

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

6h 31m

Direct flights

None
The fastest flight from St. Louis to Decatur, Illinois takes 6h 31m
There are no direct flights from St. Louis to Decatur, Illinois. There are no popular flight routes from St. Louis to Decatur, Illinois.
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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 6h 31m.

  • 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.

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

  • How do I get Price Alerts for flights from St. Louis to Decatur, Illinois?

    Search flight deals from St. Louis to Decatur, Illinois. While viewing offers you’ll have the option to create a Price Alert.

  • How can I save money on flights from St. Louis to Decatur, Illinois with momondo?

    Plan your trips smart with the “Price Forecast” feature, which uses flight data to help you pick the best days to fly for the lowest fares. Our “Price Calendar” helps you get the most for your money by showing you when it’s most advantageous to fly. Curate your own travel experiences for less with “Explore”. Expert travel hacks to fuel your next adventure are a click away with “Discover” by momondo. Set up our “Price Alerts” to track fare changes and book when prices are at their lowest point.

  • How does momondo find its flight prices?

    We show prices from over 700+ competitors with a single click. With options from airlines and OTAs from across our 30 international markets, we are able to show you a diverse range of deals to create your adventure.

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.

An easier way to manage your Decatur, Illinois trip

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