$105+ 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 6/10. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — ORD
May 18 — May 251
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 April 18, 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 April 18, 2026.
This CheapOair deal was found by Cheapflights users on 4/13. 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 8/131:04 pm
BOI
- STL
1 stop5h 19m
Frontier
Mon 8/178:08 pm
STL
- BOI
1 stop17h 01m
Frontier
Deal found 4/13![Frontier logo]()
$281
This CheapOair deal was found by Cheapflights users on 4/14. 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.
Sun 6/141:25 pm
BOI
- ORD
1 stop6h 18m
Frontier
Wed 6/179:48 pm
ORD
- BOI
1 stop15h 42m
Frontier
Deal found 4/14![Frontier logo]()
$281
This Kiwi.com deal was found by Cheapflights users on 4/17. 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 5/79:19 pm
GEG
- STL
2 stops44h 04m
Multiple Airlines
Tue 6/98:08 pm
STL
- GEG
1 stop17h 25m
Multiple Airlines
Deal found 4/17![Multiple Airlines logo]()
$284
This Alaska Airlines deal was found by Cheapflights users on 4/14. 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 5/307:01 am
GEG
- ORD
1 stop9h 49m
Alaska Airlines
Wed 6/32:10 pm
ORD
- GEG
1 stop9h 35m
Alaska Airlines
Deal found 4/14![Alaska Airlines logo]()
$286
This Expedia deal was found by Cheapflights users on 4/16. 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.
Sat 5/238:38 pm
GEG
- ORD
1 stop7h 42m
Alaska Airlines
Sun 5/247:40 am
ORD
- GEG
1 stop7h 24m
Alaska Airlines
Deal found 4/16![Alaska Airlines logo]()
$289
This American Airlines deal was found by Cheapflights users on 4/15. 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 10/61:43 pm
IDA
- ORD
Nonstop3h 17m
American Airlines
Thu 10/159:40 am
ORD
- IDA
Nonstop3h 40m
American Airlines
Deal found 4/15![American Airlines logo]()
$290
This United Airlines deal was found by Cheapflights users on 4/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/312:35 pm
IDA
- ORD
1 stop5h 38m
United Airlines
Sat 11/76:15 pm
ORD
- IDA
1 stop5h 38m
United Airlines
Deal found 4/16![United Airlines logo]()
$291
This American Airlines deal was found by Cheapflights users on 4/14. 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 5/61:22 pm
GEG
- ORD
Nonstop3h 57m
American Airlines
Wed 5/1310:21 am
ORD
- GEG
Nonstop4h 02m
American Airlines
Deal found 4/14![American Airlines logo]()
$297
This American Airlines deal was found by Cheapflights users on 4/16. 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 10/311:43 pm
IDA
- ORD
Nonstop3h 17m
American Airlines
Sat 11/71:28 pm
ORD
- IDA
1 stop10h 06m
American Airlines
Deal found 4/16![American Airlines logo]()
$300
This Expedia deal was found by Cheapflights users on 4/15. 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 6/1012:28 pm
GEG
- ORD
1 stop6h 15m
Multiple Airlines
Tue 6/167:20 am
ORD
- GEG
1 stop6h 25m
Multiple Airlines
Deal found 4/15![Multiple Airlines logo]()
$303
This American Airlines deal was found by Cheapflights users on 4/14. 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 6/92:08 pm
GEG
- ORD
Nonstop3h 59m
American Airlines
Sat 6/1311:17 am
ORD
- GEG
Nonstop3h 57m
American Airlines
Deal found 4/14![American Airlines logo]()
$306
This American Airlines deal was found by Cheapflights users on 4/15. 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 5/71:13 pm
GEG
- ORD
Nonstop3h 57m
American Airlines
Wed 5/1310:21 am
ORD
- GEG
Nonstop4h 02m
American Airlines
Deal found 4/15![American Airlines logo]()
$309
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 April 18, 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 April 18, 2026.
This Delta deal was found by Cheapflights users on 4/13. 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 5/1910:40 pm
GEG
- MDW
1 stop9h 20m
Delta
Sat 5/237:13 pm
MDW
- GEG
1 stop5h 53m
Delta
Deal found 4/13![Delta logo]()
$326
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/2212:33 pm
JAC
- ORD
Nonstop3h 10m
United Airlines
Mon 5/256:00 am
ORD
- JAC
1 stop7h 46m
United Airlines
Deal found 4/13![United Airlines logo]()
$329
This Alaska Airlines deal was found by Cheapflights users on 4/17. 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 10/74:00 pm
IDA
- ORD
1 stop6h 41m
Alaska Airlines
Sat 10/107:00 am
ORD
- IDA
1 stop8h 27m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$329
This Southwest deal was found by Cheapflights users on 4/15. 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 5/285:35 pm
GEG
- MDW
2 stops9h 00m
Southwest
Sat 5/306:00 am
MDW
- GEG
2 stops9h 45m
Southwest
Deal found 4/15![Southwest logo]()
$345
This Alaska Airlines deal was found by Cheapflights users on 4/13. 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 7/148:15 am
GEG
- ORD
1 stop8h 42m
Alaska Airlines
Thu 7/232:20 pm
ORD
- GEG
1 stop10h 47m
Alaska Airlines
Deal found 4/13![Alaska Airlines logo]()
$335
This Delta deal was found by Cheapflights users on 4/14. 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 5/2012:15 pm
BOI
- ORD
2 stops8h 35m
Delta
Sun 5/248:42 am
ORD
- BOI
1 stop5h 36m
Delta
Deal found 4/14![Delta logo]()
$340
This Southwest deal was found by Cheapflights users on 4/13. 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 5/125:15 pm
BOI
- MDW
1 stop11h 10m
Southwest
Wed 5/206:05 pm
MDW
- BOI
1 stop7h 20m
Southwest
Deal found 4/13![Southwest logo]()
$355
This United Airlines deal was found by Cheapflights users on 4/14. 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 8/2712:23 pm
BOI
- ORD
Nonstop3h 35m
United Airlines
Sun 8/308:40 am
ORD
- BOI
Nonstop3h 45m
United Airlines
Deal found 4/14![United Airlines logo]()
$355
This Delta deal was found by Cheapflights users on 4/15. 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 7/145:41 am
GEG
- ORD
2 stops9h 18m
Delta
Sat 7/185:00 pm
ORD
- GEG
1 stop9h 03m
Delta
Deal found 4/15![Delta logo]()
$340
This Southwest deal was found by Cheapflights users on 4/15. 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 8/1012:10 pm
BOI
- MDW
Nonstop3h 20m
Southwest
Fri 8/1411:40 am
MDW
- BOI
Nonstop3h 30m
Southwest
Deal found 4/15![Southwest logo]()
$355
This Alaska Airlines deal was found by Cheapflights users on 4/17. 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 5/234:03 pm
IDA
- ORD
1 stop20h 19m
Alaska Airlines
Sat 5/307:40 am
ORD
- IDA
1 stop8h 46m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$355
This United Airlines deal was found by Cheapflights users on 4/13. 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.
Mon 8/244:10 pm
IDA
- ORD
1 stop5h 31m
United Airlines
Mon 8/315:00 am
ORD
- IDA
1 stop5h 53m
United Airlines
Deal found 4/13![United Airlines logo]()
$369
This Delta deal was found by Cheapflights users on 4/15. 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 5/286:49 am
GEG
- ORD
2 stops9h 46m
Delta
Sat 5/305:30 am
ORD
- GEG
1 stop7h 57m
Delta
Deal found 4/15![Delta logo]()
$340
This Southwest deal was found by Cheapflights users on 4/12. 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 5/196:40 am
BOI
- ORD
1 stop11h 10m
Southwest
Wed 5/204:50 pm
ORD
- BOI
1 stop8h 35m
Southwest
Deal found 4/12![Southwest logo]()
$370
This Alaska Airlines deal was found by Cheapflights users on 4/13. 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 4/247:41 pm
GEG
- ORD
1 stop8h 59m
Alaska Airlines
Mon 4/276:00 am
ORD
- GEG
1 stop6h 38m
Alaska Airlines
Deal found 4/13![Alaska Airlines logo]()
$379
This Delta deal was found by Cheapflights users on 4/13. 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 5/269:16 pm
BOI
- MDW
2 stops10h 26m
Delta
Fri 5/291:22 pm
MDW
- BOI
2 stops10h 06m
Delta
Deal found 4/13![Delta logo]()
$345
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/285:54 pm
IDA
- ORD
1 stop5h 50m
United Airlines
Mon 6/15:00 am
ORD
- IDA
1 stop5h 50m
United Airlines
Deal found 4/13![United Airlines logo]()
$396
This Southwest deal was found by Cheapflights users on 4/17. 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 6/173:00 pm
BOI
- MDW
1 stop7h 35m
Southwest
Tue 6/235:25 am
MDW
- BOI
1 stop6h 40m
Southwest
Deal found 4/17![Southwest logo]()
$375
This Delta deal was found by Cheapflights users on 4/17. 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 5/247:25 am
GEG
- ORD
2 stops12h 25m
Delta
Mon 6/15:19 pm
ORD
- GEG
2 stops8h 16m
Delta
Deal found 4/17![Delta logo]()
$345
This United Airlines deal was found by Cheapflights users on 4/15. 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 6/305:54 pm
IDA
- ORD
1 stop5h 50m
United Airlines
Thu 7/25:00 am
ORD
- IDA
1 stop5h 50m
United Airlines
Deal found 4/15![United Airlines logo]()
$412
This Southwest deal was found by Cheapflights users on 4/17. 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 5/152:50 pm
GEG
- MDW
1 stop6h 50m
Southwest
Tue 5/196:05 pm
MDW
- GEG
1 stop7h 20m
Southwest
Deal found 4/17![Southwest logo]()
$378
This Alaska Airlines deal was found by Cheapflights users on 4/17. 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 6/21:59 pm
GEG
- STL
1 stop7h 55m
Alaska Airlines
Sat 6/67:41 pm
STL
- GEG
1 stop6h 18m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$416
This Delta deal was found by Cheapflights users on 4/16. 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 5/165:35 am
GEG
- ORD
2 stops9h 16m
Delta
Sat 5/231:44 pm
ORD
- GEG
2 stops11h 22m
Delta
Deal found 4/16![Delta logo]()
$345
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/144:15 pm
JAC
- ORD
1 stop7h 43m
United Airlines
Sun 8/164:30 pm
ORD
- JAC
Nonstop3h 22m
United Airlines
Deal found 4/13![United Airlines logo]()
$419
This Alaska Airlines deal was found by Cheapflights users on 4/17. 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 5/141:54 pm
IDA
- ORD
1 stop9h 05m
Alaska Airlines
Thu 5/216:00 am
ORD
- IDA
1 stop10h 26m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$419
This Southwest deal was found by Cheapflights users on 4/17. 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 6/86:25 am
GEG
- MDW
Nonstop3h 30m
Southwest
Fri 6/125:45 am
MDW
- GEG
1 stop7h 20m
Southwest
Deal found 4/17![Southwest logo]()
$387
This Delta deal was found by Cheapflights users on 4/14. 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 6/2511:45 pm
BOI
- MDW
1 stop9h 22m
Delta
Tue 6/307:16 pm
MDW
- BOI
1 stop5h 31m
Delta
Deal found 4/14![Delta logo]()
$355
This Delta deal was found by Cheapflights users on 4/12. 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 6/173:31 pm
BOI
- ORD
1 stop6h 58m
Delta
Fri 6/265:55 pm
ORD
- BOI
1 stop7h 00m
Delta
Deal found 4/12![Delta logo]()
$355
This Southwest deal was found by Cheapflights users on 4/12. 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 6/177:10 am
BOI
- MDW
Nonstop3h 20m
Southwest
Fri 6/266:40 pm
MDW
- BOI
1 stop8h 05m
Southwest
Deal found 4/12![Southwest logo]()
$397
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/125:00 am
GEG
- STL
1 stop6h 13m
United Airlines
Wed 5/138:46 am
STL
- GEG
1 stop5h 53m
United Airlines
Deal found 4/13![United Airlines logo]()
$437
Last-minute flights from Idaho to IllinoisDiscover last-minute flight deals from Idaho to Illinois. Data last updated April 18, 2026 and is based on user searches.
Discover last-minute flight deals from Idaho to Illinois. Data last updated April 18, 2026 and is based on user searches.
This Alaska Airlines deal was found by Cheapflights users on 4/12. 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 5/52:57 pm
BOI
- ORD
1 stop8h 02m
Alaska Airlines
Wed 5/66:00 am
ORD
- BOI
1 stop7h 35m
Alaska Airlines
Deal found 4/12![Alaska Airlines logo]()
$310
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/58:34 am
BOI
- ORD
Nonstop3h 39m
United Airlines
Sat 5/98:40 am
ORD
- BOI
Nonstop4h 09m
United Airlines
Deal found 4/13![United Airlines logo]()
$330
This Kiwi.com deal was found by Cheapflights users on 4/17. 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 5/79:19 pm
GEG
- STL
2 stops44h 04m
Multiple Airlines
Tue 6/98:08 pm
STL
- GEG
1 stop17h 25m
Multiple Airlines
Deal found 4/17![Multiple Airlines logo]()
$284
This United Airlines deal was found by Cheapflights users on 4/15. 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 5/92:31 pm
IDA
- ORD
1 stop5h 52m
United Airlines
Sat 6/65:00 am
ORD
- IDA
1 stop5h 50m
United Airlines
Deal found 4/15![United Airlines logo]()
$310
This Southwest deal was found by Cheapflights users on 4/15. 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 5/132:40 pm
GEG
- MDW
1 stop12h 45m
Southwest
Wed 5/202:55 pm
MDW
- GEG
1 stop10h 00m
Southwest
Deal found 4/15![Southwest logo]()
$322
This CheapOair deal was found by Cheapflights users on 4/13. 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 5/141:22 pm
BOI
- ORD
1 stop6h 10m
Frontier
Sat 5/169:37 pm
ORD
- BOI
1 stop15h 50m
Frontier
Deal found 4/13![Frontier logo]()
$317
This Kiwi.com deal was found by Cheapflights users on 4/14. 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 5/141:22 pm
BOI
- STL
1 stop29h 01m
Frontier
Sat 5/168:08 pm
STL
- BOI
1 stop17h 19m
Frontier
Deal found 4/14![Frontier logo]()
$320
This American Airlines deal was found by Cheapflights users on 4/16. 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 5/161:53 pm
BOI
- ORD
1 stop8h 55m
American Airlines
Sat 5/2311:30 am
ORD
- BOI
Nonstop3h 50m
American Airlines
Deal found 4/16![American Airlines logo]()
$326
This Delta deal was found by Cheapflights users on 4/13. 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 5/1910:40 pm
GEG
- MDW
1 stop9h 20m
Delta
Sat 5/237:13 pm
MDW
- GEG
1 stop5h 53m
Delta
Deal found 4/13![Delta logo]()
$326
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/205:26 pm
IDA
- ORD
1 stop5h 31m
United Airlines
Sun 5/245:00 am
ORD
- IDA
1 stop5h 50m
United Airlines
Deal found 4/13![United Airlines logo]()
$329
This United Airlines deal was found by Cheapflights users on 4/13. 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 5/227:30 am
JAC
- ORD
Nonstop3h 10m
United Airlines
Mon 5/254:21 pm
ORD
- JAC
Nonstop3h 21m
United Airlines
Deal found 4/13![United Airlines logo]()
$319
This American Airlines deal was found by Cheapflights users on 4/14. 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 5/293:11 pm
BOI
- ORD
Nonstop3h 53m
American Airlines
Wed 6/311:30 am
ORD
- BOI
Nonstop3h 50m
American Airlines
Deal found 4/14![American Airlines logo]()
$315
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 April 18, 2026.
Search for one-way flight options from Idaho to Illinois. Find affordable one-way fares based on user searches. Data last updated April 18, 2026.
This Frontier deal was found by Cheapflights users on 4/14. 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 6/1012:28 pm
GEG
- ORD
1 stop6h 15m
Frontier
Deal found 4/14![Frontier logo]()
$105
This Kiwi.com deal was found by Cheapflights users on 4/15. 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 5/1110:21 pm
IDA
- ORD
2 stops23h 40m
Multiple Airlines
Deal found 4/15![Multiple Airlines logo]()
$119
This Priceline deal was found by Cheapflights users on 4/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/101:22 pm
BOI
- ORD
1 stop6h 10m
Frontier
Deal found 4/17![Frontier logo]()
$125
This Frontier deal was found by Cheapflights users on 4/14. 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 6/1212:28 pm
GEG
- ORD
1 stop6h 15m
Frontier
Deal found 4/14![Frontier logo]()
$125
This Frontier deal was found by Cheapflights users on 4/17. 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 6/1712:28 pm
GEG
- ORD
1 stop6h 15m
Frontier
Deal found 4/17![Frontier logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 4/13. 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 4/2710:21 pm
IDA
- ORD
2 stops35h 02m
Multiple Airlines
Deal found 4/13![Multiple Airlines logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 4/15. 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 5/171:22 pm
BOI
- STL
1 stop29h 01m
Frontier
Deal found 4/15![Frontier logo]()
$130
This Kiwi.com deal was found by Cheapflights users on 4/14. 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 6/1510:56 pm
IDA
- ORD
1 stop29h 36m
Multiple Airlines
Deal found 4/14![Multiple Airlines logo]()
$131
This Kiwi.com deal was found by Cheapflights users on 4/16. 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 5/109:19 pm
GEG
- ORD
2 stops45h 13m
Multiple Airlines
Deal found 4/16![Multiple Airlines logo]()
$132
This Kiwi.com deal was found by Cheapflights users on 4/14. 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 5/39:19 pm
GEG
- ORD
3 stops47h 42m
Multiple Airlines
Deal found 4/14![Multiple Airlines logo]()
$136
This Kiwi.com deal was found by Cheapflights users on 4/13. 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 5/1510:21 pm
IDA
- ORD
2 stops21h 11m
Multiple Airlines
Deal found 4/13![Multiple Airlines logo]()
$136
This Alaska Airlines deal was found by Cheapflights users on 4/14. 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 8/198:31 am
GEG
- ORD
1 stop9h 24m
Alaska Airlines
Deal found 4/14![Alaska Airlines logo]()
$139
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 April 18, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $241 (CheapOair) |
One-way from | $105 (Frontier) |
Popular in | March |
Cheapest in | September |
Average price | $411 |
Good round-trip deal | $432 or less |
Good one-way deal | $205 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 April 18, 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
SpokaneChicago
GEG - MDW
GEGMDW
Spokane
Tue 5/19
10:40 pm-10:00 am
1 stop9h 20m
Chicago Midway
Sat 5/23
7:13 pm-11:06 pm
1 stop5h 53m
$326
JacksonChicago
JAC - ORD
JACORD
Jackson Hole
Fri 5/22
12:33 pm-4:43 pm
Nonstop3h 10m
Chicago O'Hare Intl
Mon 5/25
6:00 am-12:46 pm
1 stop7h 46m
$329
Idaho FallsChicago
IDA - ORD
IDAORD
Idaho Falls Fanning Field
Wed 10/7
4:00 pm-11:41 pm
1 stop6h 41m
Chicago O'Hare Intl
Sat 10/10
7:00 am-2:27 pm
1 stop8h 27m
$329
SpokaneChicago
GEG - ORD
GEGORD
Spokane
Tue 7/14
8:15 am-6:57 pm
1 stop8h 42m
Chicago O'Hare Intl
Thu 7/23
2:20 pm-11:07 pm
1 stop10h 47m
$335
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Wed 5/20
12:15 pm-9:50 pm
2 stops8h 35m
Chicago O'Hare Intl
Sun 5/24
8:42 am-1:18 pm
1 stop5h 36m
$340
SpokaneChicago
GEG - ORD
GEGORD
Spokane
Tue 7/14
5:41 am-4:59 pm
2 stops9h 18m
Chicago O'Hare Intl
Sat 7/18
5:00 pm-12:03 am
1 stop9h 03m
$340
SpokaneChicago
GEG - ORD
GEGORD
Spokane
Thu 5/28
6:49 am-6:35 pm
2 stops9h 46m
Chicago O'Hare Intl
Sat 5/30
5:30 am-11:27 am
1 stop7h 57m
$340
SpokaneChicago
GEG - MDW
GEGMDW
Spokane
Thu 5/28
5:35 pm-4:35 am
2 stops9h 00m
Chicago Midway
Sat 5/30
6:00 am-1:45 pm
2 stops9h 45m
$345
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Tue 5/26
9:16 pm-8:42 am
2 stops10h 26m
Chicago Midway
Fri 5/29
1:22 pm-10:28 pm
2 stops10h 06m
$345
SpokaneChicago
GEG - ORD
GEGORD
Spokane
Sun 5/24
7:25 am-9:50 pm
2 stops12h 25m
Chicago O'Hare Intl
Mon 6/1
5:19 pm-11:35 pm
2 stops8h 16m
$345
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
GEG-ORD
GEG-MDW
GEG-STL
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
GEG-ORD
GEG-MDW
GEG-STL
What is the cheapest month to book a flight from Idaho to Illinois?
Currently, May is the cheapest month in which you can book a flight from Idaho to Illinois (average of $87). Flying from Idaho to Illinois in March is currently the most expensive (average of $268). 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 April 18, 2026.
It’s optimal to fly from Idaho to Illinois at noon. By choosing this option you can save up to 36% on the cost of your flight, compared to a flight in the evening.
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 April 18, 2026.
The most flights from USID to USIL are scheduled on a Monday (10 on average). You will have fewer flight options on Tuesday, 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?
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 April 18, 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
Overall
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Comfort
8.0
Overall
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Comfort
8.0
Overall
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Comfort
8.0
Overall
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Comfort
8.0
Overall
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Comfort
8.0
Overall
8.0
Entertainment
7.5
Boarding
8.1
Food
7.0
Crew
8.6
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
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.
Alternative routes
Complete your trip
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Return Flight Options
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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 April 18, 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 April 18, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$123 | Average$401 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$233 | Average$381 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$239 | Average$523 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$260 | Average$374 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$261 | Average$404 | FlexibilityNo cancel fee | On-time71% |