$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 6/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ORD
Jun 10 — Jun 171
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Illinois with Cheapflights
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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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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 May 11, 2026.
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 May 11, 2026.
This Southwest deal was found by Cheapflights users on 5/7. 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 5/289:40 pm
STL
- MDW
Nonstop1h 05m
Southwest
Mon 6/17:50 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/7![Southwest logo]()
$191
This American Airlines deal was found by Cheapflights users on 5/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/221:25 pm
STL
- ORD
Nonstop1h 36m
American Airlines
Thu 9/36:59 am
ORD
- STL
Nonstop1h 25m
American Airlines
Deal found 5/10![American Airlines logo]()
$191
This American Airlines deal was found by Cheapflights users on 5/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/47:03 am
STL
- ORD
Nonstop1h 27m
American Airlines
Mon 6/811:00 pm
ORD
- STL
Nonstop1h 16m
American Airlines
Deal found 5/10![American Airlines logo]()
$192
This American Airlines deal was found by Cheapflights users on 5/7. 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.
Thu 5/286:00 am
STL
- ORD
Nonstop1h 29m
American Airlines
Mon 6/17:04 pm
ORD
- STL
Nonstop1h 26m
American Airlines
Deal found 5/7![American Airlines logo]()
$193
This Delta deal was found by Cheapflights users on 5/8. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/122:10 pm
STL
- MDW
1 stop4h 23m
Delta
Thu 8/139:24 am
MDW
- STL
1 stop3h 50m
Delta
Deal found 5/8![Delta logo]()
$194
This American Airlines deal was found by Cheapflights users on 5/9. 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 6/26:35 am
STL
- ORD
Nonstop1h 29m
American Airlines
Tue 6/93:03 pm
ORD
- STL
Nonstop1h 30m
American Airlines
Deal found 5/9![American Airlines logo]()
$194
This Delta deal was found by Cheapflights users on 5/7. 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 6/28:53 am
STL
- ORD
2 stops9h 12m
Delta
Thu 6/46:24 am
ORD
- STL
1 stop4h 08m
Delta
Deal found 5/7![Delta logo]()
$199
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/134:52 pm
STL
- ORD
1 stop15h 01m
Frontier
Fri 7/171:50 pm
ORD
- STL
1 stop19h 07m
Frontier
Deal found 5/8![Frontier logo]()
$201
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/306:31 pm
STL
- ORD
1 stop25h 19m
Frontier
Mon 7/69:57 pm
ORD
- STL
1 stop21h 26m
Frontier
Deal found 5/8![Frontier logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 5/6. 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.
Thu 7/26:31 pm
STL
- MDW
1 stop27h 40m
Frontier
Sun 7/126:00 am
MDW
- STL
1 stop11h 37m
Frontier
Deal found 5/6![Frontier logo]()
$205
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/295:06 pm
STL
- ORD
1 stop14h 57m
Frontier
Fri 7/171:50 pm
ORD
- STL
1 stop19h 07m
Frontier
Deal found 5/10![Frontier logo]()
$205
This Southwest deal was found by Cheapflights users on 5/7. 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.
Sat 5/308:45 am
STL
- MDW
2 stops8h 05m
Southwest
Mon 6/15:40 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/7![Southwest logo]()
$206
Best flights from St. Louis to IllinoisDiscover carefully curated flight deals from St. Louis to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 11, 2026.
Discover carefully curated flight deals from St. Louis to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated May 11, 2026.
This Southwest deal was found by Cheapflights users on 5/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/110:15 am
STL
- MDW
1 stop3h 50m
Southwest
Mon 6/89:35 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/8![Southwest logo]()
$201
This Delta deal was found by Cheapflights users on 5/6. 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.
Wed 7/156:21 am
STL
- ORD
2 stops6h 42m
Delta
Tue 7/213:22 pm
ORD
- STL
1 stop6h 53m
Delta
Deal found 5/6![Delta logo]()
$223
This United Airlines deal was found by Cheapflights users on 5/8. 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.
Fri 9/45:30 pm
STL
- ORD
Nonstop1h 31m
United Airlines
Tue 9/810:40 am
ORD
- STL
Nonstop1h 33m
United Airlines
Deal found 5/8![United Airlines logo]()
$264
This Southwest deal was found by Cheapflights users on 5/7. 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.
Sat 5/308:45 am
STL
- MDW
2 stops8h 05m
Southwest
Mon 6/15:40 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/7![Southwest logo]()
$206
This Delta deal was found by Cheapflights users on 5/6. 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.
Sat 5/304:00 pm
STL
- ORD
1 stop5h 20m
Delta
Sat 6/61:44 pm
ORD
- STL
2 stops9h 37m
Delta
Deal found 5/6![Delta logo]()
$226
This Southwest deal was found by Cheapflights users on 5/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/306:10 am
STL
- ORD
1 stop5h 20m
Southwest
Sat 5/301:55 pm
ORD
- STL
1 stop5h 15m
Southwest
Deal found 5/8![Southwest logo]()
$211
This Southwest deal was found by Cheapflights users on 5/7. 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.
Sat 5/306:10 am
STL
- ORD
2 stops8h 10m
Southwest
Mon 6/12:40 pm
ORD
- STL
1 stop8h 35m
Southwest
Deal found 5/7![Southwest logo]()
$222
This Delta deal was found by Cheapflights users on 5/7. 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.
Thu 9/105:30 pm
STL
- ORD
1 stop6h 27m
Delta
Sat 9/128:15 am
ORD
- STL
1 stop6h 23m
Delta
Deal found 5/7![Delta logo]()
$255
This Delta deal was found by Cheapflights users on 5/5. 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.
Tue 7/146:21 am
STL
- MDW
2 stops6h 17m
Delta
Sat 7/181:18 pm
MDW
- STL
1 stop4h 01m
Delta
Deal found 5/5![Delta logo]()
$256
This Southwest deal was found by Cheapflights users on 5/7. 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.
Wed 7/155:40 am
STL
- MDW
Nonstop1h 05m
Southwest
Sat 7/188:30 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/7![Southwest logo]()
$237
This United Airlines deal was found by Cheapflights users on 5/10. 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.
Fri 6/121:13 pm
STL
- ORD
Nonstop1h 30m
United Airlines
Sun 6/1410:00 pm
ORD
- STL
Nonstop1h 29m
United Airlines
Deal found 5/10![United Airlines logo]()
$337
This KAYAK deal was found by Cheapflights users on 5/7. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/86:30 am
STL
- MDW
1 stop6h 16m
Delta
Tue 6/99:17 am
MDW
- STL
2 stops7h 29m
Delta
Deal found 5/7![Delta logo]()
$269
This KAYAK deal was found by Cheapflights users on 5/7. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/87:12 pm
STL
- ORD
1 stop4h 47m
Delta
Tue 6/97:01 am
ORD
- STL
2 stops9h 45m
Delta
Deal found 5/7![Delta logo]()
$269
This Southwest deal was found by Cheapflights users on 5/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/307:05 am
STL
- MDW
1 stop7h 35m
Southwest
Sat 5/306:30 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/8![Southwest logo]()
$277
This Delta deal was found by Cheapflights users on 5/9. 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 8/15:42 pm
STL
- ORD
1 stop6h 11m
Delta
Sun 8/26:30 am
ORD
- STL
1 stop3h 58m
Delta
Deal found 5/9![Delta logo]()
$284
This Delta deal was found by Cheapflights users on 5/9. 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.
Mon 6/226:30 am
STL
- MDW
1 stop6h 16m
Delta
Mon 6/291:26 pm
MDW
- STL
2 stops9h 57m
Delta
Deal found 5/9![Delta logo]()
$289
This Southwest deal was found by Cheapflights users on 5/9. 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.
Mon 6/225:40 am
STL
- MDW
Nonstop1h 05m
Southwest
Sat 7/256:30 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/9![Southwest logo]()
$337
This Delta deal was found by Cheapflights users on 5/11. 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 8/223:29 pm
STL
- ORD
1 stop6h 18m
Delta
Thu 9/31:35 pm
ORD
- STL
2 stops9h 26m
Delta
Deal found 5/11![Delta logo]()
$289
This Southwest deal was found by Cheapflights users on 5/6. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 6/219:05 am
STL
- MDW
Nonstop1h 05m
Southwest
Sun 6/289:35 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/6![Southwest logo]()
$337
This Expedia deal was found by Cheapflights users on 5/6. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/37:41 pm
STL
- UIN
2 stops17h 59m
Multiple Airlines
Wed 6/109:55 am
UIN
- STL
2 stops14h 04m
Multiple Airlines
Deal found 5/6![Multiple Airlines logo]()
$1,231
This Southwest deal was found by Cheapflights users on 5/9. 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.
Sun 6/75:50 am
STL
- MDW
Nonstop1h 05m
Southwest
Fri 6/129:35 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/9![Southwest logo]()
$348
This Delta deal was found by Cheapflights users on 5/6. 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.
Wed 6/176:00 am
STL
- ORD
1 stop6h 36m
Delta
Wed 6/175:57 pm
ORD
- STL
1 stop5h 26m
Delta
Deal found 5/6![Delta logo]()
$318
This Delta deal was found by Cheapflights users on 5/9. 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.
Thu 7/166:21 am
STL
- MDW
2 stops6h 17m
Delta
Sun 7/199:19 am
MDW
- STL
1 stop3h 46m
Delta
Deal found 5/9![Delta logo]()
$362
This Delta deal was found by Cheapflights users on 5/9. 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.
Thu 7/168:48 am
STL
- ORD
2 stops9h 41m
Delta
Sun 7/196:30 am
ORD
- STL
1 stop3h 58m
Delta
Deal found 5/9![Delta logo]()
$362
This Expedia deal was found by Cheapflights users on 5/8. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/57:41 pm
STL
- UIN
2 stops16h 49m
Multiple Airlines
Fri 6/129:55 am
UIN
- STL
2 stops14h 04m
Multiple Airlines
Deal found 5/8![Multiple Airlines logo]()
$1,283
Last-minute flights from St. Louis to IllinoisDiscover last-minute flight deals from St. Louis to Illinois. Data last updated May 11, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Illinois. Data last updated May 11, 2026 and is based on user searches.
This Southwest deal was found by Cheapflights users on 5/7. 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 5/281:45 pm
STL
- MDW
Nonstop1h 10m
Southwest
Sat 6/66:30 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/7![Southwest logo]()
$191
This American Airlines deal was found by Cheapflights users on 5/7. 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.
Thu 5/286:00 am
STL
- ORD
Nonstop1h 29m
American Airlines
Mon 6/17:04 pm
ORD
- STL
Nonstop1h 26m
American Airlines
Deal found 5/7![American Airlines logo]()
$193
This United Airlines deal was found by Cheapflights users on 5/8. 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 5/307:22 am
STL
- ORD
Nonstop1h 38m
United Airlines
Sat 5/304:45 pm
ORD
- STL
Nonstop1h 29m
United Airlines
Deal found 5/8![United Airlines logo]()
$191
This Southwest deal was found by Cheapflights users on 5/7. 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.
Sat 5/308:45 am
STL
- MDW
2 stops8h 05m
Southwest
Mon 6/15:40 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 5/7![Southwest logo]()
$206
This Southwest deal was found by Cheapflights users on 5/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/306:10 am
STL
- ORD
1 stop5h 20m
Southwest
Sat 5/301:55 pm
ORD
- STL
1 stop5h 15m
Southwest
Deal found 5/8![Southwest logo]()
$211
This American Airlines deal was found by Cheapflights users on 5/9. 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 6/26:35 am
STL
- ORD
Nonstop1h 29m
American Airlines
Tue 6/93:03 pm
ORD
- STL
Nonstop1h 30m
American Airlines
Deal found 5/9![American Airlines logo]()
$194
This Delta deal was found by Cheapflights users on 5/7. 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 6/28:53 am
STL
- ORD
2 stops9h 12m
Delta
Thu 6/46:24 am
ORD
- STL
1 stop4h 08m
Delta
Deal found 5/7![Delta logo]()
$199
This American Airlines deal was found by Cheapflights users on 5/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/47:03 am
STL
- ORD
Nonstop1h 27m
American Airlines
Mon 6/811:00 pm
ORD
- STL
Nonstop1h 16m
American Airlines
Deal found 5/10![American Airlines logo]()
$192
This United Airlines deal was found by Cheapflights users on 5/7. 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 6/95:29 pm
STL
- ORD
Nonstop1h 31m
United Airlines
Wed 6/102:20 pm
ORD
- STL
Nonstop1h 26m
United Airlines
Deal found 5/7![United Airlines logo]()
$207
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 6/286:31 pm
STL
- MDW
1 stop16h 38m
Frontier
Thu 7/1612:11 pm
MDW
- STL
1 stop20h 46m
Frontier
Deal found 5/10![Frontier logo]()
$213
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/295:06 pm
STL
- ORD
1 stop14h 57m
Frontier
Fri 7/171:50 pm
ORD
- STL
1 stop19h 07m
Frontier
Deal found 5/10![Frontier logo]()
$205
This Kiwi.com deal was found by Cheapflights users on 5/8. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/306:31 pm
STL
- ORD
1 stop25h 19m
Frontier
Mon 7/69:57 pm
ORD
- STL
1 stop21h 26m
Frontier
Deal found 5/8![Frontier logo]()
$202
One-way flights from St. Louis to IllinoisSearch for one-way flight options from St. Louis to Illinois. Find affordable one-way fares based on user searches. Data last updated May 11, 2026.
Search for one-way flight options from St. Louis to Illinois. Find affordable one-way fares based on user searches. Data last updated May 11, 2026.
This Southwest deal was found by Cheapflights users on 5/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/94:00 pm
STL
- MDW
Nonstop1h 05m
Southwest
Deal found 5/10![Southwest logo]()
$59
This United Airlines deal was found by Cheapflights users on 5/8. 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.
Tue 6/95:29 pm
STL
- ORD
Nonstop1h 31m
United Airlines
Deal found 5/8![United Airlines logo]()
$59
This Kiwi.com deal was found by Cheapflights users on 5/7. 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 7/35:06 pm
STL
- ORD
1 stop14h 57m
Frontier
Deal found 5/7![Frontier logo]()
$66
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/96:31 pm
STL
- MDW
1 stop27h 40m
Frontier
Deal found 5/10![Frontier logo]()
$67
This Southwest deal was found by Cheapflights users on 5/8. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/31:45 pm
STL
- MDW
Nonstop1h 10m
Southwest
Deal found 5/8![Southwest logo]()
$69
This United Airlines deal was found by Cheapflights users on 5/7. 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 6/36:00 am
STL
- ORD
Nonstop1h 30m
United Airlines
Deal found 5/7![United Airlines logo]()
$69
This Kiwi.com deal was found by Cheapflights users on 5/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/26:33 pm
STL
- MDW
1 stop27h 29m
Frontier
Deal found 5/10![Frontier logo]()
$70
This Kiwi.com deal was found by Cheapflights users on 5/6. 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.
Mon 6/15:27 pm
STL
- ORD
1 stop14h 28m
Frontier
Deal found 5/6![Frontier logo]()
$70
This Kiwi.com deal was found by Cheapflights users on 5/6. 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.
Thu 5/286:33 pm
STL
- MDW
1 stop27h 29m
Frontier
Deal found 5/6![Frontier logo]()
$77
This Kiwi.com deal was found by Cheapflights users on 5/6. 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.
Thu 5/286:33 pm
STL
- ORD
1 stop13h 22m
Frontier
Deal found 5/6![Frontier logo]()
$77
This Southwest deal was found by Cheapflights users on 5/7. 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.
Wed 6/35:45 am
STL
- ORD
1 stop5h 25m
Southwest
Deal found 5/7![Southwest logo]()
$79
This Kiwi.com deal was found by Cheapflights users on 5/6. 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.
Fri 6/55:27 pm
STL
- MDW
1 stop28h 35m
Frontier
Deal found 5/6![Frontier logo]()
$84
Find 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 May 11, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $191 (Southwest) |
One-way from | $59 (Southwest) |
Popular in | January |
Cheapest in | August |
Average price | $331 |
Good round-trip deal | $337 or less |
Good one-way deal | $219 or less |
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 May 11, 2026.
Use the filters below to find and compare flights from St. Louis to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Mon 6/1
10:15 am-2:05 pm
1 stop3h 50m
Chicago Midway
Mon 6/8
9:35 pm-10:50 pm
Nonstop1h 15m
$201
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Sat 5/30
8:45 am-4:50 pm
2 stops8h 05m
Chicago Midway
Mon 6/1
5:40 pm-6:55 pm
Nonstop1h 15m
$206
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 5/30
6:10 am-11:30 am
1 stop5h 20m
Chicago O'Hare Intl
Sat 5/30
1:55 pm-7:10 pm
1 stop5h 15m
$211
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 5/30
6:10 am-2:20 pm
2 stops8h 10m
Chicago O'Hare Intl
Mon 6/1
2:40 pm-11:15 pm
1 stop8h 35m
$222
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 7/15
6:21 am-1:03 pm
2 stops6h 42m
Chicago O'Hare Intl
Tue 7/21
3:22 pm-10:15 pm
1 stop6h 53m
$223
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Sat 5/30
4:00 pm-9:20 pm
1 stop5h 20m
Chicago O'Hare Intl
Sat 6/6
1:44 pm-11:21 pm
2 stops9h 37m
$226
Quickest round-trip
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Wed 7/15
5:40 am-6:45 am
Nonstop1h 05m
Chicago Midway
Sat 7/18
8:30 pm-9:45 pm
Nonstop1h 15m
$237
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Thu 9/10
5:30 pm-11:57 pm
1 stop6h 27m
Chicago O'Hare Intl
Sat 9/12
8:15 am-2:38 pm
1 stop6h 23m
$255
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Tue 7/14
6:21 am-12:38 pm
2 stops6h 17m
Chicago Midway
Sat 7/18
1:18 pm-5:19 pm
1 stop4h 01m
$256
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Fri 9/4
5:30 pm-7:01 pm
Nonstop1h 31m
Chicago O'Hare Intl
Tue 9/8
10:40 am-12:13 pm
Nonstop1h 33m
$264
Showing 1-10 of 47 resultsSorted by cheapest first
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.
STL-MDW
STL-ORD
STL-UIN
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
STL-USIL
STL-MDW
STL-ORD
STL-UIN
How far ahead should I book a flight from St. Louis to Illinois?
The best time to book flights from St. Louis to Illinois is 71 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
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 $61). Flying from St. Louis to Illinois in June is currently the most expensive (average of $125). 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 May 11, 2026.
When flying from St. Louis to Illinois, the time of day you fly usually plays a role in the price. Save by searching for a flight in the morning, which can drop the price by up to 30% versus a flight at noon.
What is the cheapest day to fly from St. Louis to Illinois?
Use this chart to determine the cheapest time to fly round-trip from St. Louis to Illinois. Price data was last updated on May 9, 2026.
Travelers seeking maximum savings on their St. Louis to Illinois flight should consider departing on Sunday evenings when fares are most often at their lowest. Monday evenings flights should be avoided if possible as fares are typically the most expensive at this time.
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 May 11, 2026.
The most flights from STL to USIL are scheduled on a Saturday (84 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (70 on average).
How much does it cost to fly round-trip from St. Louis to Illinois?
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 May 11, 2026.
See what other customers who have flown with Southwest,United Airlines, andAmerican 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.
Food
7.0
Crew
8.6
Boarding
8.1
Comfort
8.0
Overall
7.9
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Crew
8.6
Boarding
8.1
Comfort
8.0
Overall
7.9
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Crew
8.6
Boarding
8.1
Comfort
8.0
Overall
7.9
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Crew
8.6
Boarding
8.1
Comfort
8.0
Overall
7.9
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Crew
8.6
Boarding
8.1
Comfort
8.0
Overall
7.9
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
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
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Complete your trip
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St. Louis and Illinois flights
Browse other St. Louis and Illinois flight options. Last updated on May 11, 2026.
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St. Louis to Illinois flights
Consider these flights traveling from St. Louis to Illinois.
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 May 11, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$97 | Average$308 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$117 | Average$457 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$125 | Average$352 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$140 | Average$227 | FlexibilityNo cancel fee | On-timeN/A |