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$74+ 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 12/26. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ORD
Dec 25 — Jan 11
Wed 12/25
Wed 1/1
1 adult, Economy
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Cheap flight deals from St. Louis to Illinois

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Illinois (USIL). 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 December 20, 2024.

Round-trip from

$148
(CheapOair)

One-way from

$74
(Booking.com)
From Lambert-St Louis to Illinois
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One-way flight from Lambert-St Louis to Illinois
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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 December 20, 2024.

This Mytrip deal was found by Cheapflights users on 12/19. 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.
Thu 12/191:00 pmSTL - ORD
1 stop18h 25mSouthern / Mokulele
Mon 1/208:15 amORD - STL
1 stop11h 55mSouthern / Mokulele
Deal found 12/19$180
This American Airlines deal was found by Cheapflights users on 12/19. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/315:45 amSTL - ORD
Nonstop1h 29mAmerican Airlines
Wed 1/18:15 amORD - STL
Nonstop1h 21mAmerican Airlines
Deal found 12/19$247
This Southwest deal was found by Cheapflights users on 12/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/316:55 pmSTL - MDW
Nonstop1h 10mSouthwest
Wed 1/17:15 amMDW - STL
Nonstop1h 20mSouthwest
Deal found 12/19$248
This Southwest deal was found by Cheapflights users on 12/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/3111:05 amSTL - ORD
2 stops7h 05mSouthwest
Wed 1/15:45 pmORD - STL
1 stop4h 20mSouthwest
Deal found 12/19$301
This Mytrip deal was found by Cheapflights users on 12/19. 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.
Thu 12/191:00 pmSTL - ORD
1 stop18h 37mMultiple Airlines
Mon 1/206:06 pmORD - STL
2 stops20h 37mMultiple Airlines
Deal found 12/19$309
This Delta deal was found by Cheapflights users on 12/19. 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.
Tue 12/316:04 amSTL - MDW
1 stop5h 04mDelta
Thu 1/25:04 pmMDW - STL
1 stop5h 02mDelta
Deal found 12/19$323
This Frontier deal was found by Cheapflights users on 12/19. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/307:43 amSTL - MDW
1 stop10h 11mFrontier
Thu 1/28:00 amMDW - STL
1 stop11h 20mFrontier
Deal found 12/19$358
This United deal was found by Cheapflights users on 12/18. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/276:25 amSTL - ORD
Nonstop1h 35mUnited Airlines
Tue 12/3112:55 pmORD - STL
Nonstop1h 29mUnited Airlines
Deal found 12/18$429
This United Airlines deal was found by Cheapflights users on 12/19. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/258:00 amSTL - DEC
1 stop6h 42mUnited Airlines
Thu 12/2610:00 amDEC - STL
1 stop4h 24mUnited Airlines
Deal found 12/19$489
This Delta deal was found by Cheapflights users on 12/19. 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.
Tue 12/246:00 amSTL - ORD
2 stops10h 40mDelta
Tue 12/3110:30 amORD - STL
1 stop6h 29mDelta
Deal found 12/19$549
This Mytrip deal was found by Cheapflights users on 12/19. 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 12/314:27 pmSTL - ORD
2 stops15h 20mSpirit Airlines
Wed 1/111:12 amORD - STL
3 stops28h 09mSpirit Airlines
Deal found 12/19$746

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 December 20, 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Thu 1/30

5:05 pm-2:42 pm

1 stop21h 37m

Chicago Midway

Sun 2/2

10:58 am-11:31 pm

1 stop12h 33m

$148

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 1/7

12:15 pm-3:50 pm

1 stop3h 35m

Chicago O'Hare Intl

Thu 1/9

8:25 am-7:55 pm

1 stop11h 30m

$151

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sat 1/4

12:15 pm-3:50 pm

1 stop3h 35m

Chicago O'Hare Intl

Mon 1/6

10:59 am-11:40 pm

1 stop12h 41m

$154

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Mon 2/3

5:40 am-7:08 am

Nonstop1h 28m

Chicago O'Hare Intl

Mon 2/10

8:45 pm-10:09 pm

Nonstop1h 24m

$242

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Fri 1/17

6:30 am-8:05 am

Nonstop1h 35m

Chicago O'Hare Intl

Fri 1/24

8:15 pm-9:45 pm

Nonstop1h 30m

$245

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Thu 1/9

7:50 am-9:00 am

Nonstop1h 10m

Chicago Midway

Mon 1/13

8:50 pm-10:05 pm

Nonstop1h 15m

$246

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Wed 1/22

6:30 am-1:08 pm

1 stop6h 38m

Chicago Midway

Thu 1/23

6:00 am-11:47 am

1 stop5h 47m

$264

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Thu 1/9

6:50 am-2:00 pm

1 stop7h 10m

Chicago O'Hare Intl

Mon 1/13

7:30 am-5:15 pm

1 stop9h 45m

$264

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Wed 1/22

6:00 am-12:55 pm

2 stops6h 55m

Chicago O'Hare Intl

Thu 1/23

6:45 am-4:53 pm

2 stops10h 08m

$274

St. LouisDecatur

STL - DEC

STLDEC

Lambert-St Louis

Fri 1/3

8:00 am-2:42 pm

1 stop6h 42m

Decatur Arpt

Tue 1/7

6:39 pm-12:16 pm

1 stop17h 37m

$394

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/20

Showing 1-10 of 22 results
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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 $317). 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 December 20, 2024.

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 December 20, 2024.

The most flights from STL to USIL are scheduled on a Friday (60 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (26 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 December 20, 2024.
Peruse reviews from past customers who have flown with Southern / Mokulele, United Airlines and Delta 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
4,821 reviews

Boarding

8.2

Comfort

8.1

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Southwest
8.1
Very good
4,821 reviews
Southwest
8.1
Very good
4,821 reviews

Boarding

8.2

Comfort

8.1

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Delta
8.0
Very good
8,601 reviews
Southwest
8.1
Very good
4,821 reviews

Boarding

8.2

Comfort

8.1

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

United Airlines
7.4
Good
9,041 reviews
Southwest
8.1
Very good
4,821 reviews

Boarding

8.2

Comfort

8.1

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,821 reviews

Boarding

8.2

Comfort

8.1

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

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 Southern / Mokulele. According to our data, you can fly for as low as $74. Users have also found prices from $80 and $123 on Frontier and Southwest, 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 - Decatur Arpt 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: Copa Airlines (96%), Japan Airlines (88%), ANA (87%).

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

    The cheapest flight price from St. Louis to Illinois is $148. On average you can expect to pay $1,402. The most popular route, (Lambert-St Louis - Chicago O'Hare Intl), can usually be booked for $99.

  • 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 $317). 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.

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Alternative routes for St. Louis to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
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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 December 20, 2024.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$115Average$259FlexibilityNo cancel feeOn-time71%
Southern / MokuleleCheapest$118Average$183FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$119Average$302FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$168Average$284FlexibilityNo cancel feeOn-time63%
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