HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Decatur

$304+ Cheap flights from St. Louis to Decatur, IL (STL - DEC)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/7. Fares are subject to change and may not be available on all flights or dates of travel.
STL — DEC
Apr 10 — Apr 171
Fri 4/10
Fri 4/17
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from St. Louis to Decatur with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from St. Louis to Decatur

Cheapest flights from St. Louis to Decatur
Explore the most affordable flight options available from St. Louis to Decatur. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 11, 2026.

This United Airlines deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/77:45 am
STL
-
DEC
1 stop25h 13m
United Airlines
Tue 4/147:37 pm
DEC
-
STL
1 stop16h 45m
United Airlines
Deal found 3/10$304
This United Airlines deal was found by Cheapflights users on 3/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/257:45 am
STL
-
DEC
1 stop5h 09m
United Airlines
Wed 4/297:37 pm
DEC
-
STL
1 stop3h 34m
United Airlines
Deal found 3/8$314
This United Airlines deal was found by Cheapflights users on 3/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/255:00 am
STL
-
DEC
1 stop3h 52m
United Airlines
Sun 3/297:20 pm
DEC
-
STL
1 stop3h 36m
United Airlines
Deal found 3/10$344

Find flight deals from St. Louis to Decatur

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Decatur (DEC). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 11, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$304
(United Airlines)
Provider with most accurate pricing for Lambert-St Louis-Decatur Arpt flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Decatur Arpt flights.
Search Deals
From Lambert-St Louis to Decatur Arpt
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Decatur 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, Cheapflights users made 2,558,603 searches. Data last updated March 11, 2026.
Use the filters below to find and compare flights from St. Louis to Decatur that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Tue 4/7

7:45 am-8:58 am

1 stop25h 13m

Decatur Arpt

Tue 4/14

7:37 pm-12:22 pm

1 stop16h 45m

$304

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Sat 4/25

7:45 am-12:54 pm

1 stop5h 09m

Decatur Arpt

Wed 4/29

7:37 pm-11:11 pm

1 stop3h 34m

$314
Quickest round-trip

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Wed 3/25

5:00 am-8:52 am

1 stop3h 52m

Decatur Arpt

Sun 3/29

7:20 pm-10:56 pm

1 stop3h 36m

$344

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/10

Sorted by cheapest first
  • Most accurate provider: When it comes to deals on St. Louis-Decatur, Illinois flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Decatur, Illinois flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Decatur, Illinois flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on St. Louis-Decatur, Illinois flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Decatur, Illinois flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from St. Louis to Decatur

Have a flexible travel schedule? Discover the best time to fly to Decatur from St. Louis with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Decatur. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from St. Louis to Decatur, Illinois?

    A quick flight from St. Louis to Decatur, Illinois can take about 25h 13m. United Airlines provides one of the quickest options available for as low as $304. St. Louis and Decatur, Illinois are separated by a distance of 110 mi.

  • Can I find deals for flights from St. Louis to Decatur that include hotel bookings?

    Yes. In addition to deals on St. Louis to Decatur flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from St. Louis to Decatur?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Decatur.

  • Can I find deals for business class flights from St. Louis to Decatur?

    Yes. Cheapflights offers flight deals from St. Louis to Decatur by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

Traveling to a place near Decatur?

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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.