HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Illinois

$59+ Cheap flights from St. Louis (STL) to Illinois

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 3/26. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ORD
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from St. Louis to Illinois 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 Illinois

Keep the following information in mind while searching for St. Louis to Illinois flight deals. Data was last updated February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$71
(Trip.com)

One-way from

$59
(Southwest)

Popular in

November

Cheapest in

May

Average price

$245

Good round-trip deal

$69 or less

Good one-way deal

$93 or less
Provider with most accurate pricing for Lambert-St Louis-Chicago (CHI) flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Chicago (CHI) flights.
Search Deals
From Lambert-St Louis to Illinois
Search Deals
One-way flight from Lambert-St Louis to Illinois
Search Deals
Highest demand for flights based on searches. 11% potential increase in price ($29 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2025
Search Deals
Price to beat on a round-trip flight from Lambert-St Louis to Illinois.
Search Deals
Price to beat on a one-way flight from Lambert-St Louis to Illinois.
Search Deals

Find flight deals from St. Louis to Illinois

Cheapest flights from St. Louis to Illinois
Explore the most affordable flight options available from St. Louis to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.

This Trip.com deal was found by Cheapflights users on 2/20. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/171:00 pmSTL - UIN
Nonstop1h 00mSouthern / Mokulele
Mon 3/2411:10 amUIN - STL
Nonstop1h 00mSouthern / Mokulele
Deal found 2/20$74
This American Airlines deal was found by Cheapflights users on 2/20. 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.
Tue 5/136:00 amSTL - ORD
Nonstop1h 23mAmerican Airlines
Thu 5/1510:21 pmORD - STL
Nonstop1h 20mAmerican Airlines
Deal found 2/20$120
This eDestinos deal was found by Cheapflights users on 2/20. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/1312:15 pmSTL - ORD
1 stop3h 35mSouthern / Mokulele
Thu 5/158:25 amORD - STL
1 stop11h 45mSouthern / Mokulele
Deal found 2/20$123
This Southwest deal was found by Cheapflights users on 2/20. 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.
Thu 3/64:00 pmSTL - MDW
1 stop6h 05mSouthwest
Mon 3/104:25 pmMDW - STL
Nonstop1h 15mSouthwest
Deal found 2/20$127
This Kiwi.com deal was found by Cheapflights users on 2/20. 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.
Fri 3/1411:00 amSTL - ORD
Nonstop1h 17mMultiple Airlines
Mon 3/178:25 amORD - STL
1 stop11h 45mMultiple Airlines
Deal found 2/20$127
This Frontier deal was found by Cheapflights users on 2/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/246:55 pmSTL - MDW
1 stop10h 36mFrontier
Mon 4/141:23 pmMDW - STL
1 stop10h 23mFrontier
Deal found 2/20$130
This Southwest deal was found by Cheapflights users on 2/20. 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.
Tue 5/135:20 amSTL - ORD
2 stops8h 40mSouthwest
Thu 5/155:45 pmORD - STL
1 stop5h 00mSouthwest
Deal found 2/20$142
This United Airlines deal was found by Cheapflights users on 2/20. 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 3/186:30 amSTL - ORD
Nonstop1h 31mUnited Airlines
Thu 3/201:01 pmORD - STL
Nonstop1h 22mUnited Airlines
Deal found 2/20$163
This Delta deal was found by Cheapflights users on 2/20. 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.
Tue 3/186:50 amSTL - MDW
1 stop5h 46mDelta
Fri 4/117:09 pmMDW - STL
1 stop3h 55mDelta
Deal found 2/20$177
This Delta deal was found by Cheapflights users on 2/19. 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.
Fri 4/410:30 amSTL - ORD
1 stop5h 41mDelta
Sat 4/196:45 amORD - STL
2 stops10h 01mDelta
Deal found 2/19$182
This Mytrip deal was found by Cheapflights users on 2/19. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/137:37 pmSTL - ORD
2 stops26h 51mSpirit Airlines
Fri 5/166:34 pmORD - STL
1 stop23h 58mSpirit Airlines
Deal found 2/19$218
This United Airlines deal was found by Cheapflights users on 2/20. 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.
Sun 3/1611:05 amSTL - DEC
1 stop21h 45mUnited Airlines
Wed 3/193:00 pmDEC - STL
1 stop23h 23mUnited Airlines
Deal found 2/20$503

Find flights from St. Louis to Illinois within your budget

Customize your flight search to find flights from St. Louis to 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, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.

Fly from

St. Louis

Fly to

Illinois

Route

Depart

Return

Price

St. LouisQuincy

STL - UIN

STLUIN

Lambert-St Louis

Mon 3/17

1:00 pm-2:00 pm

Nonstop1h 00m

Quincy Regional

Mon 3/24

11:10 am-12:10 pm

Nonstop1h 00m

$74

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 5/13

6:00 am-7:23 am

Nonstop1h 23m

Chicago O'Hare Intl

Thu 5/15

10:21 pm-11:41 pm

Nonstop1h 20m

$120

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 5/13

12:15 pm-3:50 pm

1 stop3h 35m

Chicago O'Hare Intl

Thu 5/15

8:25 am-8:10 pm

1 stop11h 45m

$123

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Thu 3/6

4:00 pm-10:05 pm

1 stop6h 05m

Chicago Midway

Mon 3/10

4:25 pm-5:40 pm

Nonstop1h 15m

$127

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Fri 3/14

11:00 am-12:17 pm

Nonstop1h 17m

Chicago O'Hare Intl

Mon 3/17

8:25 am-8:10 pm

1 stop11h 45m

$127

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Mon 3/24

6:55 pm-5:31 am

1 stop10h 36m

Chicago Midway

Mon 4/14

1:23 pm-11:46 pm

1 stop10h 23m

$130

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 5/13

5:20 am-2:00 pm

2 stops8h 40m

Chicago O'Hare Intl

Thu 5/15

5:45 pm-10:45 pm

1 stop5h 00m

$142

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 3/18

6:30 am-8:01 am

Nonstop1h 31m

Chicago O'Hare Intl

Thu 3/20

1:01 pm-2:23 pm

Nonstop1h 22m

$163

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Tue 3/18

6:50 am-12:36 pm

1 stop5h 46m

Chicago Midway

Fri 4/11

7:09 pm-11:04 pm

1 stop3h 55m

$177

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Fri 4/4

10:30 am-4:11 pm

1 stop5h 41m

Chicago O'Hare Intl

Sat 4/19

6:45 am-4:46 pm

2 stops10h 01m

$182

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/20

Showing 1-10 of 24 results
1
2
3

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

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

Travel insights for flights from St. Louis to Illinois

Get recent, data-driven insights about flights from St. Louis to Illinois including ideal travel times, pricing trends, and more.

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

Currently, August is the cheapest month in which you can book a flight from St. Louis to Illinois (average of $245). Flying from St. Louis to Illinois in March is currently the most expensive (average of $321). 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 STL to IL?

Find hourly flight availability from St. Louis to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 20, 2025.

When flying from St. Louis to Illinois, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from St. Louis to Illinois

Explore weekly flight availability from St. Louis to Illinois. 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 February 20, 2025.

The most flights from STL to USIL are scheduled on a Thursday (58 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (31 on average).

Rainfall in Illinois by month

Plan your trip to Illinois by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Illinois ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Illinois when rainfall is around 1.7 in.

Temperature in Illinois by month

Plan your trip to Illinois by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Illinois, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated February 20, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta and United Airlines from St. Louis to Illinois to help guide your decision. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Food

7.1

Crew

8.7

Overall

8.1

Comfort

8.1

Boarding

8.2

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Southwest
8.1
Very good
4,411 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Food

7.1

Crew

8.7

Overall

8.1

Comfort

8.1

Boarding

8.2

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Delta
8.0
Very good
8,220 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Food

7.1

Crew

8.7

Overall

8.1

Comfort

8.1

Boarding

8.2

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

United Airlines
7.4
Good
8,766 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Food

7.1

Crew

8.7

Overall

8.1

Comfort

8.1

Boarding

8.2

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Food

7.1

Crew

8.7

Overall

8.1

Comfort

8.1

Boarding

8.2

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Illinois. 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 from for flights from St. Louis to Illinois?

    Located just 12.7 mi from the city center, Lambert-St Louis (STL) is the airport most travelers will use when flying to Illinois from St. Louis.

  • What are the cheapest airlines to fly from St. Louis to Illinois one-way?

    For one-way options, check prices for Southwest. According to our data, you can fly for as low as $59. Users have also found prices from $59 and $62 on American Airlines and Frontier, respectively.

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

    Most travelers choose Lambert-St Louis - Chicago O'Hare Intl, Lambert-St Louis - Chicago Midway or Lambert-St Louis - Quincy Regional when deciding on the best route from St. Louis to Illinois.

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

    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 St. Louis to Illinois on time: Republic Airways (96%), Royal Jordanian (94%), ANA (86%).

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

    The cheapest flight price from St. Louis to Illinois is $125. On average you can expect to pay $1,381. The most popular route, (Lambert-St Louis - Chicago O'Hare Intl), can usually be booked for $122.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Illinois 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 St. Louis to Illinois?

    Currently, August is the cheapest month in which you can book a flight from St. Louis to Illinois (average of $245). Flying from St. Louis to Illinois in March is currently the most expensive (average of $321). 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

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.

Alternative routes for St. Louis to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
St. Louis to Seattle flights
Kansas City to Las Vegas flights
St. Louis to Las Vegas flights
Kansas City to Sky Harbor Intl flights
Kansas City to Seattle flights
Kansas City to LaGuardia flights
Kansas City to Los Angeles flights
St. Louis to Miami flights
St. Louis to Orlando flights
Kansas City to O'Hare Intl flights
St. Louis to Sky Harbor Intl flights
Kansas City to John F Kennedy Intl flights
St. Louis to Denver flights
St. Louis to Newark flights
St. Louis to LaGuardia flights
Kansas City to Newark flights
Kansas City to Orlando flights
Kansas City to Miami flights
Kansas City to Dallas/Fort Worth flights
Kansas City to Hobby flights
St. Louis to Hobby flights
St. Louis to Los Angeles flights
Kansas City to Boston flights
Kansas City to San Diego flights
Kansas City to Denver flights
Kansas City to Atlanta flights
St. Louis to John F Kennedy Intl flights
St. Louis to Dulles Intl flights
St. Louis to Atlanta flights
Kansas City to George Bush Intcntl flights
St. Louis to Dallas/Fort Worth flights
Kansas City to Dulles Intl flights
St. Louis to Boston flights
St. Louis to George Bush Intcntl flights
Kansas City to Reagan-National flights
St. Louis to Fort Lauderdale flights
Kansas City to Portland flights
Kansas City to San Francisco flights
Kansas City to Fort Lauderdale flights
St. Louis to Tampa flights
St. Louis to Honolulu flights
St. Louis to San Francisco flights
St. Louis to O'Hare Intl flights
St. Louis to Salt Lake City flights
St. Louis to Philadelphia flights
St. Louis to New Orleans flights
Kansas City to Tampa flights
St. Louis to Baltimore flights
Kansas City to Salt Lake City flights
St. Louis to Reagan-National flights

Top 4 airlines flying from St. Louis to Illinois

Discover the top 4 airlines that operate flights from St. Louis to Illinois. 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 February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$115Average$264FlexibilityNo cancel feeOn-time71%
Southern / MokuleleCheapest$118Average$181FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$120Average$295FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$168Average$280FlexibilityNo cancel feeOn-time63%
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.