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St. Louis

$49+ Cheap flights from Illinois to St. Louis (STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/31. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — STL
dic. 6 — dic. 131
sáb. 12/6
sáb. 12/13
1 adult, Economy
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Find flight deals from Illinois to St. Louis

Cheapest flights from Illinois to St. Louis
Explore the most affordable flight options available from Illinois to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on noviembre 6, 2025.

This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 12/102:49 pmMDW - STL
1 stop20h 18mFrontier
vie. 12/1210:42 amSTL - MDW
1 stop9h 00mFrontier
Deal found 11/5$135
This Southwest deal was found by Cheapflights users on 11/5. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 12/91:55 pmMDW - STL
1 stop5h 30mSouthwest
mié. 12/108:25 amSTL - MDW
1 stop5h 10mSouthwest
Deal found 11/5$137
This Southwest deal was found by Cheapflights users on 11/5. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 12/92:15 pmORD - STL
1 stop7h 20mSouthwest
mié. 12/108:25 amSTL - ORD
1 stop3h 50mSouthwest
Deal found 11/5$137
This American Airlines deal was found by Cheapflights users on 11/6. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 12/86:41 amORD - STL
Nonstop1h 27mAmerican Airlines
mié. 12/105:05 amSTL - ORD
Nonstop1h 30mAmerican Airlines
Deal found 11/6$144
This Kiwi.com deal was found by Cheapflights users on 11/6. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 12/104:01 pmORD - STL
1 stop19h 06mFrontier
vie. 12/1212:07 pmSTL - ORD
1 stop8h 48mFrontier
Deal found 11/6$147
This Priceline deal was found by Cheapflights users on 11/4. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/191:56 pmMDW - STL
1 stop9h 05mFrontier
jue. 11/203:14 pmSTL - MDW
1 stop7h 29mFrontier
Deal found 11/4$150
This Expedia deal was found by Cheapflights users on 11/5. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/1912:37 pmORD - STL
1 stop10h 24mFrontier
jue. 11/203:14 pmSTL - ORD
1 stop8h 54mFrontier
Deal found 11/5$150
This Delta deal was found by Cheapflights users on 11/5. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/47:02 pmMDW - STL
1 stop4h 27mDelta
dom. 12/76:00 amSTL - MDW
1 stop5h 55mDelta
Deal found 11/5$157
This Delta deal was found by Cheapflights users on 11/6. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 12/315:31 pmORD - STL
1 stop6h 07mDelta
mar. 1/135:00 pmSTL - ORD
1 stop6h 57mDelta
Deal found 11/6$157
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 12/88:42 pmMDW - STL
2 stops25h 51mFrontier
sáb. 12/137:43 pmSTL - MDW
1 stop15h 25mFrontier
Deal found 11/5$158
This United Airlines deal was found by Cheapflights users on 11/5. 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.
jue. 12/410:50 amORD - STL
Nonstop1h 25mUnited Airlines
dom. 12/75:27 pmSTL - ORD
Nonstop1h 23mUnited Airlines
Deal found 11/5$162
This Kiwi.com deal was found by Cheapflights users on 11/5. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/45:05 amORD - STL
1 stop6h 02mFrontier
jue. 12/111:16 pmSTL - ORD
2 stops34h 56mFrontier
Deal found 11/5$165

Cheap flight deals from Illinois to St. Louis

Keep the following information in mind while searching for Illinois to St. Louis flight deals. Data was last updated noviembre 6, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$121
(Southwest)

One-way from

$49
(Southwest)

Popular in

October

Cheapest in

August

Average price

$300

Good round-trip deal

$61 or less

Good one-way deal

$128 or less
Provider with most accurate pricing for Chicago (CHI)-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-Lambert-St Louis flights.
Search Deals
From Illinois to Lambert-St Louis
Search Deals
One-way flight from Illinois to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 9% potential increase in price ($34 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
Search Deals
Price to beat on a round-trip flight from Illinois to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Illinois to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois to St. Louis 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 noviembre 6, 2025.
Use the filters below to find and compare flights from Illinois to St. Louis that are best for you.

Fly from

Illinois

Fly to

St. Louis

Route

Depart

Return

Price

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

lun. 12/8

6:41 am-8:08 am

Nonstop1h 27m

Lambert-St Louis

mié. 12/10

5:05 am-6:35 am

Nonstop1h 30m

$144

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

jue. 12/4

5:13 pm-11:42 pm

1 stop6h 29m

Lambert-St Louis

lun. 12/8

5:12 pm-11:47 pm

1 stop6h 35m

$157

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

jue. 12/4

7:02 pm-11:29 pm

1 stop4h 27m

Lambert-St Louis

dom. 12/7

6:00 am-11:55 am

1 stop5h 55m

$157

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

mié. 12/31

5:31 pm-11:38 pm

1 stop6h 07m

Lambert-St Louis

mar. 1/13

5:00 pm-11:57 pm

1 stop6h 57m

$157

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

jue. 12/4

10:50 am-12:15 pm

Nonstop1h 25m

Lambert-St Louis

dom. 12/7

5:27 pm-6:50 pm

Nonstop1h 23m

$162

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

mar. 12/30

9:10 pm-10:43 pm

Nonstop1h 33m

Lambert-St Louis

mar. 1/13

6:40 pm-8:23 pm

Nonstop1h 43m

$170

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

lun. 12/8

2:30 pm-11:29 pm

2 stops8h 59m

Lambert-St Louis

mié. 12/10

6:00 am-1:50 pm

2 stops7h 50m

$184

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

mar. 12/2

8:10 am-1:30 pm

1 stop5h 20m

Lambert-St Louis

mar. 12/9

1:50 pm-2:55 pm

Nonstop1h 05m

$197

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

lun. 12/8

2:30 pm-11:29 pm

2 stops8h 59m

Lambert-St Louis

sáb. 12/13

6:00 am-2:17 pm

2 stops8h 17m

$201

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

sáb. 12/6

6:00 am-10:33 pm

2 stops16h 33m

Lambert-St Louis

dom. 12/7

10:42 am-10:12 pm

1 stop11h 30m

$209

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/4

Showing 1-10 of 50 results
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Best time to book a flight from Illinois to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Illinois 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.

Cheapflights Insights

Everything you need to know about your flight from Illinois to St. Louis

What is the cheapest month to book a flight from Illinois to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Illinois to St. Louis (average of $77). Flying from Illinois to St. Louis in February is currently the most expensive (average of $161). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to STL?

Find hourly flight availability from Illinois to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated noviembre 6, 2025.

It’s typically best to fly out from Illinois to St. Louis in the evening. Doing so could potentially save you 31% on the flight price compared to flying in the afternoon, which is usually more expensive.

What is the cheapest day to fly from Illinois to St. Louis?

Use this chart to determine the cheapest time to fly round-trip from Illinois to St. Louis. Price data was last updated on November 24, 2024.

Travelers seeking maximum savings on their Illinois to St. Louis flight should consider departing on Thursday mornings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Illinois to St. Louis

Explore weekly flight availability from Illinois to St. Louis. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated noviembre 6, 2025.

The most flights from USIL to STL are scheduled on a Thursday (59 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (37 on average).

Related info for your journey

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

  • What airport do you fly into for flights to St. Louis from Illinois?

    If you book a flight to St. Louis from Illinois, you will be flying to Lambert-St Louis, which is the city’s only airport. Lambert-St Louis (STL) is located 12.7 mi from the center of St. Louis.

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

    Airlines like American Airlines, Delta, and United Airlines fly from Illinois to St. Louis in about 1h 25m. The time it takes to get you to your destination can typically vary by up to 5h 04m. There are 258 mi between Illinois and St. Louis. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the most popular routes from Illinois to St. Louis?

    When deciding which route to take from Illinois to St. Louis consider Chicago O'Hare Intl - Lambert-St Louis, Chicago Midway - Lambert-St Louis or Springfield Capital - Lambert-St Louis as they are the most popular.

  • What are the most reliable airlines from Illinois to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Illinois to St. Louis on time: Envoy Air (92%), Turkish Airlines (90%), United Airlines (89%).

  • What are the cheapest flights from Illinois to St. Louis?

    Looking at all options, your cheapest flight can be booked for $63. While the most popular route (Chicago O'Hare Intl - Lambert-St Louis) can be booked for $101 on average, our data indicates $283 when flying from Illinois to St. Louis.

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

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

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

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

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

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

  • What is the cheapest month to book a flight from Illinois to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Illinois to St. Louis (average of $77). Flying from Illinois to St. Louis in February is currently the most expensive (average of $161). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

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Alternative routes for Illinois to St. Louis

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Top 4 airlines flying from Illinois to St. Louis

Discover the top 4 airlines that operate flights from Illinois to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated noviembre 6, 2025.
AirlineCheapestAverageFlexibilityOn-time
SouthwestCheapest$77Average$298FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$115Average$299FlexibilityNo cancel feeOn-time71%
Southern / MokuleleCheapest$145Average$214FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$152Average$306FlexibilityNo cancel feeOn-time69%

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