$39+ 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 9/3. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ORD
Jul 8 — Jul 151
1 adult, Economy
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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
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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 July 3, 2025.
Round-trip from | $70 (Trip.com) |
|---|---|
One-way from | $39 (Orbitz) |
Popular in | June |
Cheapest in | August |
Average price | $208 |
Good round-trip deal | $167 or less |
Good one-way deal | $109 or less |
Find flight deals from St. Louis to Illinois
Cheapest flights from St. Louis to IllinoisExplore 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 July 3, 2025.
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 July 3, 2025.
This Trip.com deal was found by Cheapflights users on 7/2. 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.
Wed 7/239:20 amSTL - UIN
Nonstop1h 00mSouthern / Mokulele
Wed 7/307:50 amUIN - STL
Nonstop1h 00mSouthern / Mokulele
Deal found 7/2![Southern / Mokulele logo]()
$70
This Southwest deal was found by Cheapflights users on 7/2. 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 7/298:35 pmSTL - MDW
Nonstop1h 05mSouthwest
Wed 7/309:45 pmMDW - STL
Nonstop1h 10mSouthwest
Deal found 7/2![Southwest logo]()
$91
This American Airlines deal was found by Cheapflights users on 7/3. 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.
Sat 8/97:44 pmSTL - ORD
Nonstop1h 31mAmerican Airlines
Tue 8/127:00 pmORD - STL
Nonstop1h 25mAmerican Airlines
Deal found 7/3![American Airlines logo]()
$91
This Southwest deal was found by Cheapflights users on 7/1. 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 8/122:25 pmSTL - ORD
1 stop7h 05mSouthwest
Tue 8/267:30 amORD - STL
1 stop7h 00mSouthwest
Deal found 7/1![Southwest logo]()
$111
This Priceline deal was found by Cheapflights users on 7/3. 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.
Thu 9/114:00 pmSTL - ORD
1 stop8h 10mFrontier
Sun 9/145:10 amORD - STL
1 stop9h 54mFrontier
Deal found 7/3![Frontier logo]()
$112
This United Airlines deal was found by Cheapflights users on 7/1. 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.
Thu 7/318:00 amSTL - ORD
Nonstop1h 25mUnited Airlines
Thu 8/79:20 pmORD - STL
Nonstop1h 25mUnited Airlines
Deal found 7/1![United Airlines logo]()
$124
This Priceline deal was found by Cheapflights users on 7/1. 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.
Sat 7/122:52 pmSTL - MDW
1 stop7h 43mFrontier
Sun 7/136:20 amMDW - STL
1 stop7h 14mFrontier
Deal found 7/1![Frontier logo]()
$162
This Jettzy deal was found by Cheapflights users on 6/30. 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 Jettzy is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/21:00 pmSTL - ORD
1 stop18h 37mSouthern / Mokulele
Mon 8/48:15 amORD - STL
1 stop3h 55mSouthern / Mokulele
Deal found 6/30![Southern / Mokulele logo]()
$165
This Delta deal was found by Cheapflights users on 7/1. 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.
Sat 8/96:40 amSTL - MDW
1 stop5h 49mDelta
Tue 8/129:31 amMDW - STL
1 stop3h 49mDelta
Deal found 7/1![Delta logo]()
$177
This Delta deal was found by Cheapflights users on 7/3. 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.
Sat 8/910:30 amSTL - ORD
1 stop6h 03mDelta
Tue 8/127:05 amORD - STL
1 stop7h 36mDelta
Deal found 7/3![Delta logo]()
$177
This FlightHub deal was found by Cheapflights users on 7/2. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/262:52 pmSTL - ORD
1 stop8h 37mMultiple Airlines
Tue 7/291:10 pmORD - STL
1 stop3h 35mMultiple Airlines
Deal found 7/2![Multiple Airlines logo]()
$180
This United Airlines deal was found by Cheapflights users on 7/1. 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 10/412:25 pmSTL - DEC
1 stop20h 26mUnited Airlines
Tue 10/79:38 amDEC - STL
1 stop4h 49mUnited Airlines
Deal found 7/1![United Airlines logo]()
$286
Cheapflights Fare Finder
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 July 3, 2025.
Use the filters below to find and compare flights from St. Louis to Illinois that are best for you.
Fly from
St. Louis
Fly to
Illinois
Route
Depart
Return
Price
St. LouisQuincy
STL - UIN
STLUIN
Lambert-St Louis
Wed 7/23
9:20 am-10:20 am
Nonstop1h 00m
Quincy Regional
Wed 7/30
7:50 am-8:50 am
Nonstop1h 00m
$70
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Tue 7/29
8:35 pm-9:40 pm
Nonstop1h 05m
Chicago Midway
Wed 7/30
9:45 pm-10:55 pm
Nonstop1h 10m
$91
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 8/9
7:44 pm-9:15 pm
Nonstop1h 31m
Chicago O'Hare Intl
Tue 8/12
7:00 pm-8:25 pm
Nonstop1h 25m
$91
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Tue 8/12
2:25 pm-9:30 pm
1 stop7h 05m
Chicago O'Hare Intl
Tue 8/26
7:30 am-2:30 pm
1 stop7h 00m
$111
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 9/11
4:00 pm-12:10 am
1 stop8h 10m
Chicago O'Hare Intl
Sun 9/14
5:10 am-3:04 pm
1 stop9h 54m
$112
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 7/31
8:00 am-9:25 am
Nonstop1h 25m
Chicago O'Hare Intl
Thu 8/7
9:20 pm-10:45 pm
Nonstop1h 25m
$124
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Sat 7/12
2:52 pm-10:35 pm
1 stop7h 43m
Chicago Midway
Sun 7/13
6:20 am-1:34 pm
1 stop7h 14m
$162
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 8/2
1:00 pm-7:37 am
1 stop18h 37m
Chicago O'Hare Intl
Mon 8/4
8:15 am-12:10 pm
1 stop3h 55m
$165
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Sat 8/9
6:00 am-11:48 am
1 stop5h 48m
Chicago Midway
Tue 8/12
10:31 am-2:41 pm
1 stop4h 10m
$177
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 8/9
10:30 am-4:33 pm
1 stop6h 03m
Chicago O'Hare Intl
Tue 8/12
7:05 am-2:41 pm
1 stop7h 36m
$177
Showing 1-10 of 26 results
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.
Cheapflights Insights
Everything you need to know about your flight from St. Louis to Illinois
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 July 3, 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 July 3, 2025.
The most flights from STL to USIL are scheduled on a Wednesday (63 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (11 on average).
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 July 3, 2025.
See what other customers who have flown with Southwest, Delta, and United Airlines from St. Louis to Illinois have to say. 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.
Boarding
8.2
Entertainment
7.6
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Reviews
1 / 20
8.0
ExcellentJohn,May 2025
PVD - BNA
Boarding
8.2
Entertainment
7.6
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Reviews
1 / 20
8.0
ExcellentJohn,May 2025
PVD - BNA
Boarding
8.2
Entertainment
7.6
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Reviews
1 / 20
8.0
ExcellentJohn,May 2025
PVD - BNA
Boarding
8.2
Entertainment
7.6
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Reviews
1 / 20
8.0
ExcellentJohn,May 2025
PVD - BNA
Boarding
8.2
Entertainment
7.6
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Reviews
1 / 20
8.0
ExcellentJohn,May 2025
PVD - BNA
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.
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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.
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 July 3, 2025.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$115 | Average$271 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$118 | Average$190 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$133 | Average$312 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$168 | Average$286 | FlexibilityNo cancel fee | On-time63% |