$119+ Cheap flights from Idaho 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 9/10. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — ORD
Aug 22 — Aug 291
Round-trip
1 adult, Economy
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Cheapest flights from Idaho to IllinoisExplore the most affordable flight options available from Idaho to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 23, 2026.
Explore the most affordable flight options available from Idaho to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 23, 2026.
This CheapOair deal was found by Cheapflights users on 7/21. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/131:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Mon 8/178:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 7/21![Frontier logo]()
$254
This American Airlines deal was found by Cheapflights users on 7/22. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/171:50 pm
IDA
- ORD
Nonstop3h 34m
American Airlines
Sat 10/2410:30 am
ORD
- IDA
Nonstop3h 50m
American Airlines
Deal found 7/22![American Airlines logo]()
$271
This Frontier deal was found by Cheapflights users on 7/19. 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.
Thu 9/312:24 pm
BOI
- STL
1 stop5h 49m
Frontier
Wed 9/912:46 pm
STL
- BOI
1 stop27h 11m
Frontier
Deal found 7/19![Frontier logo]()
$272
This CheapOair deal was found by Cheapflights users on 7/21. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/103:52 pm
BOI
- STL
1 stop18h 59m
Frontier
Sun 9/1312:46 pm
STL
- BOI
1 stop27h 11m
Frontier
Deal found 7/21![Frontier logo]()
$286
This American Airlines deal was found by Cheapflights users on 7/19. 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.
Wed 9/21:43 pm
IDA
- ORD
Nonstop3h 35m
American Airlines
Sun 9/610:35 am
ORD
- IDA
Nonstop3h 34m
American Airlines
Deal found 7/19![American Airlines logo]()
$290
This Delta deal was found by Cheapflights users on 7/19. 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.
Sat 8/226:00 am
IDA
- ORD
1 stop4h 59m
Delta
Tue 8/252:00 pm
ORD
- IDA
1 stop5h 20m
Delta
Deal found 7/19![Delta logo]()
$291
This Southwest deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/106:00 am
GEG
- MDW
Nonstop3h 30m
Southwest
Mon 9/148:50 pm
MDW
- GEG
Nonstop3h 50m
Southwest
Deal found 7/20![Southwest logo]()
$297
This American Airlines deal was found by Cheapflights users on 7/22. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/192:27 pm
GEG
- ORD
Nonstop4h 01m
American Airlines
Tue 8/2511:30 am
ORD
- GEG
Nonstop4h 07m
American Airlines
Deal found 7/22![American Airlines logo]()
$297
This Kiwi.com deal was found by Cheapflights users on 7/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/812:23 pm
BOI
- STL
1 stop5h 52m
Frontier
Tue 10/138:10 pm
STL
- BOI
2 stops43h 47m
Frontier
Deal found 7/21![Frontier logo]()
$300
This CheapOair deal was found by Cheapflights users on 7/19. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/93:52 pm
BOI
- STL
1 stop8h 25m
Frontier
Sat 10/108:10 pm
STL
- BOI
1 stop16h 18m
Frontier
Deal found 7/19![Frontier logo]()
$301
This Alaska Airlines deal was found by Cheapflights users on 7/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1712:41 pm
GEG
- ORD
1 stop9h 16m
Alaska Airlines
Wed 11/182:07 pm
ORD
- GEG
1 stop6h 37m
Alaska Airlines
Deal found 7/21![Alaska Airlines logo]()
$301
This Delta deal was found by Cheapflights users on 7/21. 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 8/263:17 pm
IDA
- ORD
1 stop5h 16m
Delta
Wed 9/27:48 am
ORD
- IDA
1 stop7h 47m
Delta
Deal found 7/21![Delta logo]()
$301
Best flights from Idaho to IllinoisDiscover carefully curated flight deals from Idaho to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 23, 2026.
Discover carefully curated flight deals from Idaho to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 23, 2026.
This Delta deal was found by Cheapflights users on 7/19. 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.
Sat 8/226:00 am
IDA
- ORD
1 stop4h 59m
Delta
Tue 8/252:00 pm
ORD
- IDA
1 stop5h 20m
Delta
Deal found 7/19![Delta logo]()
$291
This Alaska Airlines deal was found by Cheapflights users on 7/22. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/197:03 am
GEG
- ORD
1 stop10h 18m
Alaska Airlines
Tue 8/256:00 am
ORD
- GEG
1 stop8h 31m
Alaska Airlines
Deal found 7/22![Alaska Airlines logo]()
$301
This United Airlines deal was found by Cheapflights users on 7/18. 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 Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/264:04 pm
IDA
- ORD
1 stop5h 42m
United Airlines
Wed 9/25:00 am
ORD
- IDA
1 stop5h 51m
United Airlines
Deal found 7/18![United Airlines logo]()
$310
This American Airlines deal was found by Cheapflights users on 7/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/272:27 pm
GEG
- ORD
Nonstop4h 01m
American Airlines
Mon 8/3111:30 am
ORD
- GEG
Nonstop4h 07m
American Airlines
Deal found 7/18![American Airlines logo]()
$321
This Southwest deal was found by Cheapflights users on 7/22. 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 9/84:55 pm
GEG
- MDW
1 stop10h 05m
Southwest
Fri 9/1110:15 am
MDW
- GEG
1 stop7h 20m
Southwest
Deal found 7/22![Southwest logo]()
$322
This Kiwi.com deal was found by Cheapflights users on 7/19. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/93:52 pm
BOI
- STL
2 stops16h 48m
Frontier
Sat 10/108:10 pm
STL
- BOI
1 stop16h 18m
Frontier
Deal found 7/19![Frontier logo]()
$381
This Delta deal was found by Cheapflights users on 7/22. 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 12/96:45 pm
IDA
- ORD
2 stops12h 49m
Delta
Sat 12/127:30 am
ORD
- IDA
1 stop5h 57m
Delta
Deal found 7/22![Delta logo]()
$306
This United Airlines deal was found by Cheapflights users on 7/19. 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.
Thu 9/244:05 pm
IDA
- ORD
1 stop5h 41m
United Airlines
Thu 10/15:00 am
ORD
- IDA
1 stop5h 53m
United Airlines
Deal found 7/19![United Airlines logo]()
$329
This Southwest deal was found by Cheapflights users on 7/21. 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 8/177:30 am
BOI
- MDW
2 stops8h 50m
Southwest
Mon 8/245:40 am
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 7/21![Southwest logo]()
$332
This Delta deal was found by Cheapflights users on 7/21. 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 8/263:17 pm
IDA
- ORD
1 stop5h 16m
Delta
Wed 9/26:00 am
ORD
- IDA
2 stops9h 35m
Delta
Deal found 7/21![Delta logo]()
$306
This Alaska Airlines deal was found by Cheapflights users on 7/22. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/272:06 pm
BOI
- STL
1 stop8h 53m
Alaska Airlines
Wed 10/287:02 am
STL
- BOI
1 stop8h 09m
Alaska Airlines
Deal found 7/22![Alaska Airlines logo]()
$363
This Southwest deal was found by Cheapflights users on 7/22. 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 9/124:05 pm
BOI
- MDW
2 stops11h 25m
Southwest
Tue 9/1510:30 am
MDW
- BOI
2 stops10h 15m
Southwest
Deal found 7/22![Southwest logo]()
$337
This United Airlines deal was found by Cheapflights users on 7/22. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/244:05 pm
IDA
- ORD
1 stop5h 41m
United Airlines
Mon 9/285:00 am
ORD
- IDA
1 stop5h 53m
United Airlines
Deal found 7/22![United Airlines logo]()
$339
This Delta deal was found by Cheapflights users on 7/19. 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.
Thu 8/2011:35 am
IDA
- ORD
1 stop5h 44m
Delta
Tue 8/258:48 am
ORD
- IDA
2 stops10h 32m
Delta
Deal found 7/19![Delta logo]()
$315
This American Airlines deal was found by Cheapflights users on 7/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/91:50 pm
BOI
- STL
1 stop8h 53m
American Airlines
Tue 9/153:34 pm
STL
- BOI
1 stop7h 53m
American Airlines
Deal found 7/18![American Airlines logo]()
$385
This Alaska Airlines deal was found by Cheapflights users on 7/21. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/317:20 am
GEG
- STL
1 stop6h 24m
Alaska Airlines
Wed 11/47:00 am
STL
- GEG
1 stop7h 45m
Alaska Airlines
Deal found 7/21![Alaska Airlines logo]()
$363
This Southwest deal was found by Cheapflights users on 7/22. 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.
Fri 9/116:00 am
BOI
- MDW
2 stops10h 00m
Southwest
Tue 9/154:40 pm
MDW
- BOI
2 stops7h 35m
Southwest
Deal found 7/22![Southwest logo]()
$342
This United Airlines deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/31:37 pm
GEG
- ORD
1 stop8h 22m
United Airlines
Sun 9/67:00 am
ORD
- GEG
1 stop7h 35m
United Airlines
Deal found 7/20![United Airlines logo]()
$342
This Delta deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/236:57 pm
IDA
- STL
1 stop4h 47m
Delta
Sat 9/268:00 am
STL
- IDA
1 stop5h 15m
Delta
Deal found 7/20![Delta logo]()
$319
This Alaska Airlines deal was found by Cheapflights users on 7/23. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/97:46 pm
GEG
- ORD
1 stop8h 34m
Alaska Airlines
Tue 10/137:00 am
ORD
- GEG
1 stop9h 40m
Alaska Airlines
Deal found 7/23![Alaska Airlines logo]()
$365
This United Airlines deal was found by Cheapflights users on 7/23. 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.
Thu 9/34:25 pm
JAC
- ORD
1 stop6h 34m
United Airlines
Sun 9/63:56 pm
ORD
- JAC
1 stop5h 44m
United Airlines
Deal found 7/23![United Airlines logo]()
$349
This Delta deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/263:17 pm
IDA
- ORD
1 stop5h 16m
Delta
Mon 8/312:00 pm
ORD
- IDA
1 stop5h 20m
Delta
Deal found 7/20![Delta logo]()
$320
This Southwest deal was found by Cheapflights users on 7/21. 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.
Thu 8/206:00 am
BOI
- MDW
2 stops10h 00m
Southwest
Sat 9/55:05 pm
MDW
- BOI
1 stop5h 25m
Southwest
Deal found 7/21![Southwest logo]()
$355
This Alaska Airlines deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/246:09 am
IDA
- STL
1 stop8h 35m
Alaska Airlines
Wed 10/287:02 am
STL
- IDA
1 stop9h 18m
Alaska Airlines
Deal found 7/20![Alaska Airlines logo]()
$369
This American Airlines deal was found by Cheapflights users on 7/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/215:20 am
GEG
- STL
2 stops10h 45m
American Airlines
Sat 8/295:42 am
STL
- GEG
2 stops10h 27m
American Airlines
Deal found 7/18![American Airlines logo]()
$450
This Delta deal was found by Cheapflights users on 7/23. 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.
Tue 12/17:55 am
GEG
- ORD
1 stop7h 19m
Delta
Tue 12/151:55 pm
ORD
- GEG
2 stops10h 53m
Delta
Deal found 7/23![Delta logo]()
$322
This Southwest deal was found by Cheapflights users on 7/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/253:40 pm
BOI
- MDW
1 stop6h 40m
Southwest
Tue 9/16:00 pm
MDW
- BOI
1 stop6h 10m
Southwest
Deal found 7/18![Southwest logo]()
$355
This United Airlines deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/92:41 pm
BOI
- ORD
1 stop7h 05m
United Airlines
Sun 9/138:40 am
ORD
- BOI
Nonstop3h 48m
United Airlines
Deal found 7/20![United Airlines logo]()
$361
This Alaska Airlines deal was found by Cheapflights users on 7/19. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/96:23 am
BOI
- STL
1 stop6h 58m
Alaska Airlines
Tue 9/156:08 pm
STL
- BOI
1 stop6h 47m
Alaska Airlines
Deal found 7/19![Alaska Airlines logo]()
$385
This Southwest deal was found by Cheapflights users on 7/19. 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 8/1812:35 pm
BOI
- MDW
2 stops8h 15m
Southwest
Mon 8/2411:40 am
MDW
- BOI
Nonstop3h 30m
Southwest
Deal found 7/19![Southwest logo]()
$359
Last-minute flights from Idaho to IllinoisDiscover last-minute flight deals from Idaho to Illinois. Data last updated July 23, 2026 and is based on user searches.
Discover last-minute flight deals from Idaho to Illinois. Data last updated July 23, 2026 and is based on user searches.
This CheapOair deal was found by Cheapflights users on 7/21. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/131:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Mon 8/178:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 7/21![Frontier logo]()
$254
This United Airlines deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/154:04 pm
IDA
- ORD
1 stop6h 55m
United Airlines
Sat 8/297:00 am
ORD
- IDA
1 stop7h 29m
United Airlines
Deal found 7/20![United Airlines logo]()
$310
This American Airlines deal was found by Cheapflights users on 7/22. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/192:27 pm
GEG
- ORD
Nonstop4h 01m
American Airlines
Tue 8/2511:30 am
ORD
- GEG
Nonstop4h 07m
American Airlines
Deal found 7/22![American Airlines logo]()
$297
This Alaska Airlines deal was found by Cheapflights users on 7/22. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/197:03 am
GEG
- ORD
1 stop10h 18m
Alaska Airlines
Tue 8/256:00 am
ORD
- GEG
1 stop8h 31m
Alaska Airlines
Deal found 7/22![Alaska Airlines logo]()
$301
This Delta deal was found by Cheapflights users on 7/19. 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.
Thu 8/2011:35 am
IDA
- ORD
1 stop5h 44m
Delta
Tue 8/258:48 am
ORD
- IDA
2 stops10h 32m
Delta
Deal found 7/19![Delta logo]()
$315
This American Airlines deal was found by Cheapflights users on 7/21. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/203:38 pm
JAC
- ORD
Nonstop3h 27m
American Airlines
Sun 8/2312:59 pm
ORD
- JAC
Nonstop3h 18m
American Airlines
Deal found 7/21![American Airlines logo]()
$319
This Delta deal was found by Cheapflights users on 7/19. 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.
Sat 8/226:00 am
IDA
- ORD
1 stop4h 59m
Delta
Tue 8/252:00 pm
ORD
- IDA
1 stop5h 20m
Delta
Deal found 7/19![Delta logo]()
$291
This Delta deal was found by Cheapflights users on 7/23. 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 8/2212:36 pm
GEG
- ORD
1 stop9h 21m
Delta
Thu 8/2712:54 pm
ORD
- GEG
1 stop8h 20m
Delta
Deal found 7/23![Delta logo]()
$317
This Delta deal was found by Cheapflights users on 7/22. 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.
Mon 8/2410:56 pm
GEG
- MDW
1 stop9h 03m
Delta
Mon 8/317:25 pm
MDW
- GEG
1 stop5h 44m
Delta
Deal found 7/22![Delta logo]()
$317
This Delta deal was found by Cheapflights users on 7/21. 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 8/263:17 pm
IDA
- ORD
1 stop5h 16m
Delta
Wed 9/27:48 am
ORD
- IDA
1 stop7h 47m
Delta
Deal found 7/21![Delta logo]()
$301
This Delta deal was found by Cheapflights users on 7/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/263:17 pm
IDA
- ORD
1 stop5h 16m
Delta
Mon 8/312:00 pm
ORD
- IDA
1 stop5h 20m
Delta
Deal found 7/20![Delta logo]()
$320
This Alaska Airlines deal was found by Cheapflights users on 7/22. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/277:03 am
GEG
- ORD
1 stop10h 18m
Alaska Airlines
Mon 8/312:18 pm
ORD
- GEG
1 stop10h 31m
Alaska Airlines
Deal found 7/22![Alaska Airlines logo]()
$311
One-way flights from Idaho to IllinoisSearch for one-way flight options from Idaho to Illinois. Find affordable one-way fares based on user searches. Data last updated July 23, 2026.
Search for one-way flight options from Idaho to Illinois. Find affordable one-way fares based on user searches. Data last updated July 23, 2026.
This Trip.com deal was found by Cheapflights users on 7/22. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:59 pm
BOI
- ORD
1 stop7h 36m
Frontier
Deal found 7/22![Frontier logo]()
$119
This Kiwi.com deal was found by Cheapflights users on 7/22. 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 9/2212:59 pm
BOI
- ORD
1 stop7h 36m
Frontier
Deal found 7/22![Frontier logo]()
$122
This Kiwi.com deal was found by Cheapflights users on 7/22. 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 9/2412:59 pm
BOI
- ORD
1 stop7h 36m
Frontier
Deal found 7/22![Frontier logo]()
$123
This Kiwi.com deal was found by Cheapflights users on 7/22. 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 10/2012:23 pm
BOI
- ORD
1 stop20h 38m
Frontier
Deal found 7/22![Frontier logo]()
$124
This Frontier deal was found by Cheapflights users on 7/19. 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.
Tue 9/1512:59 pm
BOI
- ORD
1 stop7h 36m
Frontier
Deal found 7/19![Frontier logo]()
$127
This Frontier deal was found by Cheapflights users on 7/22. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/223:52 pm
BOI
- ORD
1 stop12h 50m
Frontier
Deal found 7/22![Frontier logo]()
$133
This Kiwi.com deal was found by Cheapflights users on 7/22. 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 8/181:24 pm
BOI
- ORD
2 stops25h 35m
Frontier
Deal found 7/22![Frontier logo]()
$137
This Kiwi.com deal was found by Cheapflights users on 7/22. 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.
Mon 10/193:52 pm
BOI
- ORD
1 stop12h 50m
Frontier
Deal found 7/22![Frontier logo]()
$142
This Frontier deal was found by Cheapflights users on 7/19. 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.
Fri 9/183:52 pm
BOI
- ORD
1 stop12h 50m
Frontier
Deal found 7/19![Frontier logo]()
$144
This Kiwi.com deal was found by Cheapflights users on 7/23. 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 10/199:33 pm
IDA
- ORD
2 stops47h 01m
Multiple Airlines
Deal found 7/23![Multiple Airlines logo]()
$148
This Southwest deal was found by Cheapflights users on 7/22. 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 9/216:00 am
GEG
- MDW
Nonstop3h 30m
Southwest
Deal found 7/22![Southwest logo]()
$149
This American Airlines deal was found by Cheapflights users on 7/22. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/302:09 pm
GEG
- ORD
Nonstop4h 06m
American Airlines
Deal found 7/22![American Airlines logo]()
$149
Find flight deals from Idaho to Illinois
Keep the following information in mind while searching for Idaho to Illinois flight deals. Data was last updated July 23, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $254 (CheapOair) |
One-way from | $119 (Trip.com) |
Popular in | March |
Cheapest in | February |
Average price | $423 |
Good round-trip deal | $411 or less |
Good one-way deal | $229 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Idaho 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 23, 2026.
Use the filters below to find and compare flights from Idaho to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Sat 8/22
6:00 am-11:59 am
1 stop4h 59m
Chicago O'Hare Intl
Tue 8/25
2:00 pm-6:20 pm
1 stop5h 20m
$291
SpokaneChicago
GEG - ORD
GEGORD
Spokane
Wed 8/19
7:03 am-7:21 pm
1 stop10h 18m
Chicago O'Hare Intl
Tue 8/25
6:00 am-12:31 pm
1 stop8h 31m
$301
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Wed 12/9
6:45 pm-8:34 am
2 stops12h 49m
Chicago O'Hare Intl
Sat 12/12
7:30 am-12:27 pm
1 stop5h 57m
$306
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Wed 8/26
3:17 pm-9:33 pm
1 stop5h 16m
Chicago O'Hare Intl
Wed 9/2
6:00 am-2:35 pm
2 stops9h 35m
$306
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Wed 8/26
4:04 pm-10:46 pm
1 stop5h 42m
Chicago O'Hare Intl
Wed 9/2
5:00 am-9:51 am
1 stop5h 51m
$310
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Thu 8/20
11:35 am-6:19 pm
1 stop5h 44m
Chicago O'Hare Intl
Tue 8/25
8:48 am-6:20 pm
2 stops10h 32m
$315
Idaho FallsSt. Louis
IDA - STL
IDASTL
Idaho Falls Fanning Field
Wed 9/23
6:57 pm-12:44 am
1 stop4h 47m
Lambert-St Louis
Sat 9/26
8:00 am-12:15 pm
1 stop5h 15m
$319
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Wed 8/26
3:17 pm-9:33 pm
1 stop5h 16m
Chicago O'Hare Intl
Mon 8/31
2:00 pm-6:20 pm
1 stop5h 20m
$320
Quickest round-trip
SpokaneChicago
GEG - ORD
GEGORD
Spokane
Thu 8/27
2:27 pm-8:28 pm
Nonstop4h 01m
Chicago O'Hare Intl
Mon 8/31
11:30 am-1:37 pm
Nonstop4h 07m
$321
SpokaneChicago
GEG - MDW
GEGMDW
Spokane
Tue 9/8
4:55 pm-5:00 am
1 stop10h 05m
Chicago Midway
Fri 9/11
10:15 am-3:35 pm
1 stop7h 20m
$322
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Idaho to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Idaho with our price prediction graph.
BOI-STL
IDA-ORD
GEG-ORD
GEG-MDW
JAC-ORD
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 Idaho to Illinois
USID-USIL
BOI-STL
IDA-ORD
GEG-ORD
GEG-MDW
What is the cheapest month to book a flight from Idaho to Illinois?
Currently, February is the cheapest month in which you can book a flight from Idaho to Illinois (average of $340). Flying from Idaho to Illinois in March is currently the most expensive (average of $459). 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 ID to IL?
Find hourly flight availability from Idaho 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 23, 2026.
It’s optimal to fly from Idaho to Illinois in the afternoon. By choosing this option you can save up to 30% on the cost of your flight, compared to a flight in the morning.
Weekly flight availability from Idaho to Illinois
Explore weekly flight availability from Idaho 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 23, 2026.
The most flights from USID to USIL are scheduled on a Monday (9 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (6 on average).
How much does it cost to fly round-trip from Idaho to Illinois?
Airfare is typical for this route at the moment.
Idaho to Illinois flights typically cost between $302 and $456 in October.The cheapest round-trip price found within the last 5 days was $328 on Frontier (Oct 12-Oct 19).
How far ahead should I book a flight from Idaho to Illinois?
Booking 90 days in advance of your planned departure date is, on average, the best time to get cheap flights from Idaho to Illinois. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
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 23, 2026.
Read through reviews of airlines operating flights from Idaho to Illinois, such as Southwest,Alaska Airlines, andDelta. 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.
Comfort
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Comfort
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Overall
8.0
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Related info for your journey
Find useful and relevant information for your journey from Idaho to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
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Alternative routes for Idaho to Illinois
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Idaho to Illinois by cabin class
Find flights from Idaho to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Idaho and Illinois flights
Browse other Idaho and Illinois flight options. Last updated on July 23, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Find a return flight route from Illinois
Find the right flight back to Idaho after your stay in Illinois
Idaho to Illinois flights
Consider these flights traveling from Idaho to Illinois.
Top 5 airlines flying from Idaho to Illinois
Discover the top 5 airlines that operate flights from Idaho 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 23, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$228 | Average$417 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$242 | Average$428 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$249 | Average$489 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$268 | Average$450 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$298 | Average$390 | FlexibilityNo cancel fee | On-time75% |