$46+ 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 3/21. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ORD
Mar 27 — Apr 31
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 February 25, 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 February 25, 2026.
This Southwest deal was found by Cheapflights users on 2/24. 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 4/1112:25 pm
STL
- MDW
1 stop4h 30m
Southwest
Sat 4/189:15 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/24![Southwest logo]()
$197
This American Airlines deal was found by Cheapflights users on 2/24. 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 5/168:00 am
STL
- ORD
Nonstop1h 37m
American Airlines
Sat 5/161:54 pm
ORD
- STL
1 stop5h 36m
American Airlines
Deal found 2/24![American Airlines logo]()
$197
This Kiwi.com deal was found by Cheapflights users on 2/23. 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 3/2312:16 pm
STL
- ORD
1 stop20h 07m
Multiple Airlines
Mon 3/305:11 am
ORD
- STL
2 stops29h 21m
Multiple Airlines
Deal found 2/23![Multiple Airlines logo]()
$198
This Kiwi.com deal was found by Cheapflights users on 2/24. 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 3/2411:27 am
STL
- ORD
1 stop20h 56m
Frontier
Tue 3/318:55 pm
ORD
- STL
2 stops12h 53m
Frontier
Deal found 2/24![Frontier logo]()
$200
This Southwest deal was found by Cheapflights users on 2/22. 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 4/148:45 pm
STL
- MDW
Nonstop1h 05m
Southwest
Tue 4/211:55 pm
MDW
- STL
Nonstop1h 10m
Southwest
Deal found 2/22![Southwest logo]()
$201
This American Airlines deal was found by Cheapflights users on 2/24. 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.
Mon 5/45:51 am
STL
- ORD
Nonstop1h 30m
American Airlines
Tue 5/58:39 am
ORD
- STL
1 stop5h 54m
American Airlines
Deal found 2/24![American Airlines logo]()
$201
This Kiwi.com deal was found by Cheapflights users on 2/22. 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 3/2611:21 am
STL
- MDW
1 stop8h 26m
Frontier
Mon 3/306:00 am
MDW
- STL
1 stop28h 32m
Frontier
Deal found 2/22![Frontier logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 2/22. 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 4/144:59 pm
STL
- ORD
2 stops40h 11m
Multiple Airlines
Tue 4/211:40 pm
ORD
- STL
1 stop17h 10m
Multiple Airlines
Deal found 2/22![Multiple Airlines logo]()
$203
This Expedia deal was found by Cheapflights users on 2/24. 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 3/1111:32 am
STL
- MDW
1 stop10h 47m
Frontier
Fri 3/136:05 am
MDW
- STL
1 stop7h 29m
Frontier
Deal found 2/24![Frontier logo]()
$205
This Frontier deal was found by Cheapflights users on 2/24. 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.
Wed 3/1111:32 am
STL
- ORD
1 stop6h 25m
Frontier
Fri 3/1311:21 am
ORD
- STL
1 stop7h 44m
Frontier
Deal found 2/24![Frontier logo]()
$205
This Delta deal was found by Cheapflights users on 2/23. 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 3/2812:28 pm
STL
- MDW
1 stop6h 12m
Delta
Mon 3/307:20 pm
MDW
- STL
1 stop4h 05m
Delta
Deal found 2/23![Delta logo]()
$206
This Delta deal was found by Cheapflights users on 2/21. 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 3/1812:04 pm
STL
- ORD
1 stop6h 49m
Delta
Thu 3/269:50 am
ORD
- STL
1 stop5h 23m
Delta
Deal found 2/21![Delta 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 February 25, 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 February 25, 2026.
This Southwest deal was found by Cheapflights users on 2/21. 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.
Fri 4/104:10 pm
STL
- MDW
1 stop5h 05m
Southwest
Sun 4/128:15 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/21![Southwest logo]()
$206
This Delta deal was found by Cheapflights users on 2/22. 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 5/206:45 am
STL
- ORD
1 stop3h 42m
Delta
Wed 5/278:42 am
ORD
- STL
1 stop5h 49m
Delta
Deal found 2/22![Delta logo]()
$247
This United Airlines deal was found by Cheapflights users on 2/21. 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 3/137:41 am
STL
- ORD
Nonstop1h 29m
United Airlines
Tue 3/174:35 pm
ORD
- STL
Nonstop1h 25m
United Airlines
Deal found 2/21![United Airlines logo]()
$308
This Southwest deal was found by Cheapflights users on 2/22. 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 4/55:20 am
STL
- MDW
Nonstop1h 10m
Southwest
Sun 4/512:30 pm
MDW
- STL
Nonstop1h 10m
Southwest
Deal found 2/22![Southwest logo]()
$206
This Southwest deal was found by Cheapflights users on 2/22. 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 5/35:25 am
STL
- MDW
Nonstop1h 10m
Southwest
Sun 5/178:15 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/22![Southwest logo]()
$207
This Southwest deal was found by Cheapflights users on 2/22. 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 3/265:30 am
STL
- MDW
Nonstop1h 10m
Southwest
Mon 3/305:40 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/22![Southwest logo]()
$217
This Delta deal was found by Cheapflights users on 2/22. 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.
Sun 4/56:32 am
STL
- ORD
1 stop6h 45m
Delta
Sun 4/57:00 pm
ORD
- STL
1 stop4h 25m
Delta
Deal found 2/22![Delta logo]()
$277
This Southwest deal was found by Cheapflights users on 2/22. 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 3/235:30 am
STL
- MDW
Nonstop1h 10m
Southwest
Mon 3/305:40 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/22![Southwest logo]()
$217
This United Airlines deal was found by Cheapflights users on 2/21. 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 3/65:00 am
STL
- DEC
1 stop3h 52m
United Airlines
Tue 3/107:15 pm
DEC
- STL
1 stop3h 44m
United Airlines
Deal found 2/21![United Airlines logo]()
$314
This Southwest deal was found by Cheapflights users on 2/22. 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 3/188:50 pm
STL
- MDW
Nonstop1h 05m
Southwest
Thu 3/197:45 am
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/22![Southwest logo]()
$231
This KAYAK deal was found by Cheapflights users on 2/23. 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 3/306:32 am
STL
- MDW
1 stop5h 57m
Delta
Tue 3/312:05 pm
MDW
- STL
2 stops9h 53m
Delta
Deal found 2/23![Delta logo]()
$308
This United Airlines deal was found by Cheapflights users on 2/23. 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 6/128:15 pm
STL
- ORD
Nonstop1h 38m
United Airlines
Sun 6/1410:40 am
ORD
- STL
Nonstop1h 31m
United Airlines
Deal found 2/23![United Airlines logo]()
$317
This United Airlines deal was found by Cheapflights users on 2/21. 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 6/2810:20 am
STL
- ORD
Nonstop1h 32m
United Airlines
Tue 6/307:45 pm
ORD
- STL
Nonstop1h 31m
United Airlines
Deal found 2/21![United Airlines logo]()
$317
This Southwest deal was found by Cheapflights users on 2/21. 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 3/187:30 am
STL
- ORD
1 stop5h 20m
Southwest
Thu 3/264:15 pm
ORD
- STL
1 stop7h 50m
Southwest
Deal found 2/21![Southwest logo]()
$248
This Delta deal was found by Cheapflights users on 2/23. 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 5/2310:15 am
STL
- ORD
1 stop6h 14m
Delta
Sun 5/319:10 am
ORD
- STL
1 stop4h 00m
Delta
Deal found 2/23![Delta logo]()
$337
This Delta deal was found by Cheapflights users on 2/23. 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 5/257:01 pm
STL
- ORD
1 stop4h 58m
Delta
Fri 6/57:00 am
ORD
- STL
1 stop6h 10m
Delta
Deal found 2/23![Delta logo]()
$337
This Southwest deal was found by Cheapflights users on 2/21. 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 3/118:50 pm
STL
- MDW
Nonstop1h 05m
Southwest
Sat 3/145:40 pm
MDW
- STL
Nonstop1h 15m
Southwest
Deal found 2/21![Southwest logo]()
$267
This Delta deal was found by Cheapflights users on 2/24. 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 5/276:21 am
STL
- ORD
2 stops6h 40m
Delta
Fri 6/57:00 am
ORD
- STL
1 stop6h 10m
Delta
Deal found 2/24![Delta logo]()
$342
This Southwest deal was found by Cheapflights users on 2/21. 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 3/165:20 pm
STL
- MDW
1 stop5h 30m
Southwest
Mon 3/236:10 pm
MDW
- STL
1 stop5h 55m
Southwest
Deal found 2/21![Southwest logo]()
$273
This Southwest deal was found by Cheapflights users on 2/22. 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 5/302:05 pm
ORD
- STL
1 stop6h 15m
Southwest
Deal found 2/22![Southwest logo]()
$280
This Southwest deal was found by Cheapflights users on 2/24. 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 4/117:05 am
STL
- ORD
1 stop8h 25m
Southwest
Sat 4/181:55 pm
ORD
- STL
1 stop5h 15m
Southwest
Deal found 2/24![Southwest logo]()
$284
This Southwest deal was found by Cheapflights users on 2/21. 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 4/71:15 pm
STL
- MDW
2 stops6h 20m
Southwest
Tue 4/1411:35 am
MDW
- STL
2 stops6h 20m
Southwest
Deal found 2/21![Southwest logo]()
$297
This Southwest deal was found by Cheapflights users on 2/24. 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 7/125:50 am
STL
- MDW
Nonstop1h 05m
Southwest
Sun 7/121:10 pm
MDW
- STL
Nonstop1h 10m
Southwest
Deal found 2/24![Southwest logo]()
$317
This United Airlines deal was found by Cheapflights users on 2/25. 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 3/11:11 pm
STL
- DEC
1 stop4h 43m
United Airlines
Tue 3/37:15 pm
DEC
- STL
1 stop26h 25m
United Airlines
Deal found 2/25![United Airlines logo]()
$870
Last-minute flights from St. Louis to IllinoisDiscover last-minute flight deals from St. Louis to Illinois. Data last updated February 25, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Illinois. Data last updated February 25, 2026 and is based on user searches.
This Expedia deal was found by Cheapflights users on 2/24. 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 3/1111:32 am
STL
- MDW
1 stop10h 47m
Frontier
Fri 3/136:05 am
MDW
- STL
1 stop7h 29m
Frontier
Deal found 2/24![Frontier logo]()
$205
This Frontier deal was found by Cheapflights users on 2/24. 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.
Wed 3/1111:32 am
STL
- ORD
1 stop6h 25m
Frontier
Fri 3/1311:21 am
ORD
- STL
1 stop7h 44m
Frontier
Deal found 2/24![Frontier logo]()
$205
This Southwest deal was found by Cheapflights users on 2/22. 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 3/164:45 pm
STL
- MDW
Nonstop1h 05m
Southwest
Wed 3/188:15 am
MDW
- STL
Nonstop1h 20m
Southwest
Deal found 2/22![Southwest logo]()
$201
This Delta deal was found by Cheapflights users on 2/21. 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 3/1812:04 pm
STL
- ORD
1 stop6h 49m
Delta
Thu 3/269:50 am
ORD
- STL
1 stop5h 23m
Delta
Deal found 2/21![Delta logo]()
$206
This Kiwi.com deal was found by Cheapflights users on 2/23. 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 3/208:12 pm
STL
- ORD
1 stop28h 26m
Frontier
Mon 3/234:51 pm
ORD
- STL
1 stop17h 41m
Frontier
Deal found 2/23![Frontier logo]()
$211
This Kiwi.com deal was found by Cheapflights users on 2/23. 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.
Sat 3/218:12 pm
STL
- ORD
1 stop13h 31m
Frontier
Mon 3/234:51 pm
ORD
- STL
1 stop17h 41m
Frontier
Deal found 2/23![Frontier logo]()
$212
This Kiwi.com deal was found by Cheapflights users on 2/23. 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 3/2312:16 pm
STL
- ORD
1 stop20h 07m
Multiple Airlines
Mon 3/305:11 am
ORD
- STL
2 stops29h 21m
Multiple Airlines
Deal found 2/23![Multiple Airlines logo]()
$198
This Kiwi.com deal was found by Cheapflights users on 2/24. 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 3/2411:27 am
STL
- ORD
1 stop20h 56m
Frontier
Tue 3/318:55 pm
ORD
- STL
2 stops12h 53m
Frontier
Deal found 2/24![Frontier logo]()
$200
This Kiwi.com deal was found by Cheapflights users on 2/22. 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 3/2611:21 am
STL
- MDW
1 stop8h 26m
Frontier
Mon 3/306:00 am
MDW
- STL
1 stop28h 32m
Frontier
Deal found 2/22![Frontier logo]()
$202
This Kiwi.com deal was found by Cheapflights users on 2/22. 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 3/2611:21 am
STL
- MDW
1 stop10h 58m
Multiple Airlines
Mon 3/3010:00 am
MDW
- STL
2 stops24h 32m
Multiple Airlines
Deal found 2/22![Multiple Airlines logo]()
$213
This Delta deal was found by Cheapflights users on 2/23. 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 3/2812:28 pm
STL
- MDW
1 stop6h 12m
Delta
Mon 3/307:20 pm
MDW
- STL
1 stop4h 05m
Delta
Deal found 2/23![Delta logo]()
$206
This Delta deal was found by Cheapflights users on 2/23. 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 3/2812:28 pm
STL
- MDW
1 stop6h 12m
Delta
Tue 3/311:10 pm
MDW
- STL
2 stops10h 48m
Delta
Deal found 2/23![Delta logo]()
$211
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 February 25, 2026.
Search for one-way flight options from St. Louis to Illinois. Find affordable one-way fares based on user searches. Data last updated February 25, 2026.
This United Airlines deal was found by Cheapflights users on 2/21. 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 3/217:00 pm
STL
- ORD
Nonstop1h 33m
United Airlines
Deal found 2/21![United Airlines logo]()
$46
This Southwest deal was found by Cheapflights users on 2/24. 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 4/85:35 am
STL
- MDW
Nonstop1h 10m
Southwest
Deal found 2/24![Southwest logo]()
$48
This Southwest deal was found by Cheapflights users on 2/23. 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 5/208:45 pm
STL
- MDW
Nonstop1h 05m
Southwest
Deal found 2/23![Southwest logo]()
$49
This United Airlines deal was found by Cheapflights users on 2/24. 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 4/87:45 am
STL
- ORD
Nonstop1h 26m
United Airlines
Deal found 2/24![United Airlines logo]()
$49
This Southwest deal was found by Cheapflights users on 2/24. 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 4/97:20 am
STL
- MDW
Nonstop1h 10m
Southwest
Deal found 2/24![Southwest logo]()
$58
This Southwest deal was found by Cheapflights users on 2/24. 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 5/67:35 am
STL
- ORD
1 stop5h 15m
Southwest
Deal found 2/24![Southwest logo]()
$58
This Southwest deal was found by Cheapflights users on 2/24. 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 5/34:40 pm
STL
- MDW
Nonstop1h 10m
Southwest
Deal found 2/24![Southwest logo]()
$59
This United Airlines deal was found by Cheapflights users on 2/24. 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 4/248:15 pm
STL
- ORD
Nonstop1h 29m
United Airlines
Deal found 2/24![United Airlines logo]()
$59
This American Airlines deal was found by Cheapflights users on 2/23. 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.
Mon 3/236:00 am
STL
- ORD
Nonstop1h 28m
American Airlines
Deal found 2/23![American Airlines logo]()
$60
This Southwest deal was found by Cheapflights users on 2/22. 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 4/253:40 pm
STL
- MDW
1 stop5h 25m
Southwest
Deal found 2/22![Southwest logo]()
$69
This Southwest deal was found by Cheapflights users on 2/22. 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 4/137:35 am
STL
- ORD
1 stop5h 15m
Southwest
Deal found 2/22![Southwest logo]()
$69
This Southwest deal was found by Cheapflights users on 2/22. 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 4/115:40 am
STL
- MDW
Nonstop1h 10m
Southwest
Deal found 2/22![Southwest logo]()
$72
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 February 25, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $197 (Southwest) |
One-way from | $46 (United Airlines) |
Popular in | January |
Cheapest in | August |
Average price | $448 |
Good round-trip deal | $350 or less |
Good one-way deal | $194 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 February 25, 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
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Fri 4/10
4:10 pm-9:15 pm
1 stop5h 05m
Chicago Midway
Sun 4/12
8:15 am-9:30 am
Nonstop1h 15m
$206
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Sun 4/5
5:20 am-6:30 am
Nonstop1h 10m
Chicago Midway
Sun 4/5
12:30 pm-1:40 pm
Nonstop1h 10m
$206
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Sun 5/3
5:25 am-6:35 am
Nonstop1h 10m
Chicago Midway
Sun 5/17
8:15 am-9:30 am
Nonstop1h 15m
$207
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Thu 3/26
5:30 am-6:40 am
Nonstop1h 10m
Chicago Midway
Mon 3/30
5:40 pm-6:55 pm
Nonstop1h 15m
$217
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Mon 3/23
5:30 am-6:40 am
Nonstop1h 10m
Chicago Midway
Mon 3/30
5:40 pm-6:55 pm
Nonstop1h 15m
$217
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Wed 3/18
8:50 pm-9:55 pm
Nonstop1h 05m
Chicago Midway
Thu 3/19
7:45 am-9:00 am
Nonstop1h 15m
$231
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 5/20
6:45 am-10:27 am
1 stop3h 42m
Chicago O'Hare Intl
Wed 5/27
8:42 am-2:31 pm
1 stop5h 49m
$247
St. LouisChicago
STL - ORD
STLORD
Lambert-St Louis
Wed 3/18
7:30 am-12:50 pm
1 stop5h 20m
Chicago O'Hare Intl
Thu 3/26
4:15 pm-12:05 am
1 stop7h 50m
$248
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Wed 3/11
8:50 pm-9:55 pm
Nonstop1h 05m
Chicago Midway
Sat 3/14
5:40 pm-6:55 pm
Nonstop1h 15m
$267
St. LouisChicago
STL - MDW
STLMDW
Lambert-St Louis
Mon 3/16
5:20 pm-10:50 pm
1 stop5h 30m
Chicago Midway
Mon 3/23
6:10 pm-12:05 am
1 stop5h 55m
$273
Showing 1-10 of 46 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-DEC
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-DEC
What is the cheapest month to book a flight from St. Louis to Illinois?
Currently, November is the cheapest month in which you can book a flight from St. Louis to Illinois (average of $77). Flying from St. Louis to Illinois in March is currently the most expensive (average of $169). 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 25, 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 34% 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 February 21, 2026.
Travelers seeking maximum savings on their St. Louis to Illinois flight should consider departing on Wednesday at noon when fares are most often at their lowest. Sunday afternoons 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 February 25, 2026.
The most flights from STL to USIL are scheduled on a Wednesday (73 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (29 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 February 25, 2026.
See what other customers who have flown with Southwest, United Airlines, and American 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.
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Entertainment
7.5
Crew
8.6
Food
7.0
Overall
8.0
Comfort
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
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
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
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Find flights from St. Louis to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
St. Louis and Illinois flights
Browse other St. Louis and Illinois flight options. Last updated on February 25, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
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 February 25, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$97 | Average$290 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$109 | Average$330 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$117 | Average$350 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$140 | Average$212 | FlexibilityNo cancel fee | On-timeN/A |