$122+ Cheap flights from Boise (BOI) 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 8/11. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — ORD
Jul 23 — Jul 301
Round-trip
1 adult, Economy
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Cheapest flights from Boise to IllinoisExplore the most affordable flight options available from Boise to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 23, 2026.
Explore the most affordable flight options available from Boise to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 23, 2026.
This CheapOair deal was found by Cheapflights users on 6/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/161:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Sat 7/188:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/20![Frontier logo]()
$286
This Expedia deal was found by Cheapflights users on 6/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/61:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Tue 8/186:02 am
STL
- BOI
1 stop9h 05m
Multiple Airlines
Deal found 6/21![Multiple Airlines logo]()
$319
This American Airlines deal was found by Cheapflights users on 6/21. 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.
Sat 10/172:57 pm
BOI
- MLI
1 stop7h 09m
American Airlines
Wed 10/216:22 am
MLI
- BOI
1 stop7h 10m
American Airlines
Deal found 6/21![American Airlines logo]()
$329
This Travelocity deal was found by Cheapflights users on 6/19. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2412:59 pm
BOI
- ORD
1 stop20h 02m
Frontier
Mon 10/510:40 pm
ORD
- BOI
1 stop14h 24m
Frontier
Deal found 6/19![Frontier logo]()
$330
This Expedia deal was found by Cheapflights users on 6/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/61:24 pm
BOI
- ORD
1 stop6h 28m
Multiple Airlines
Mon 8/108:20 pm
ORD
- BOI
1 stop14h 17m
Multiple Airlines
Deal found 6/21![Multiple Airlines logo]()
$331
This American Airlines deal was found by Cheapflights users on 6/18. 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 8/133:16 pm
BOI
- MLI
1 stop7h 52m
American Airlines
Sat 8/2211:32 am
MLI
- BOI
2 stops12h 08m
American Airlines
Deal found 6/18![American Airlines logo]()
$334
This Alaska Airlines deal was found by Cheapflights users on 6/18. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/128:00 pm
BOI
- ORD
1 stop16h 21m
Alaska Airlines
Wed 8/196:01 am
ORD
- BOI
1 stop9h 01m
Alaska Airlines
Deal found 6/18![Alaska Airlines logo]()
$335
This American Airlines deal was found by Cheapflights users on 6/22. 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 8/82:58 pm
BOI
- ORD
Nonstop3h 51m
American Airlines
Sat 8/1511:12 am
ORD
- BOI
Nonstop3h 50m
American Airlines
Deal found 6/22![American Airlines logo]()
$336
This CheapOair deal was found by Cheapflights users on 6/18. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/21:25 pm
BOI
- STL
1 stop28h 28m
Frontier
Wed 7/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/18![Frontier logo]()
$339
This Expedia deal was found by Cheapflights users on 6/20. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2412:59 pm
BOI
- ORD
1 stop20h 02m
Multiple Airlines
Sat 9/267:00 pm
ORD
- BOI
1 stop15h 56m
Multiple Airlines
Deal found 6/20![Multiple Airlines logo]()
$339
This CheapOair deal was found by Cheapflights users on 6/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/141:24 pm
BOI
- ORD
1 stop6h 28m
Frontier
Mon 7/279:57 pm
ORD
- BOI
1 stop15h 32m
Frontier
Deal found 6/20![Frontier logo]()
$340
This Trip.com deal was found by Cheapflights users on 6/18. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/37:57 am
BOI
- ORD
1 stop10h 00m
Alaska Airlines
Mon 8/106:20 am
ORD
- BOI
1 stop8h 26m
Alaska Airlines
Deal found 6/18![Alaska Airlines logo]()
$349
Best flights from Boise to IllinoisDiscover carefully curated flight deals from Boise to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 23, 2026.
Discover carefully curated flight deals from Boise to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 23, 2026.
This American Airlines deal was found by Cheapflights users on 6/19. 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.
Sat 10/172:57 pm
BOI
- MLI
1 stop7h 09m
American Airlines
Wed 10/216:22 am
MLI
- BOI
1 stop7h 10m
American Airlines
Deal found 6/19![American Airlines logo]()
$329
This Alaska Airlines deal was found by Cheapflights users on 6/19. 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 8/128:00 pm
BOI
- ORD
1 stop16h 21m
Alaska Airlines
Wed 8/196:01 am
ORD
- BOI
1 stop9h 01m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$345
This Southwest deal was found by Cheapflights users on 6/22. 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 9/2612:55 pm
BOI
- MDW
1 stop6h 50m
Southwest
Tue 9/293:15 pm
MDW
- BOI
1 stop9h 05m
Southwest
Deal found 6/22![Southwest logo]()
$355
This Delta deal was found by Cheapflights users on 6/22. 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.
Sat 9/265:30 am
BOI
- MDW
1 stop6h 50m
Delta
Tue 9/299:59 am
MDW
- BOI
2 stops8h 55m
Delta
Deal found 6/22![Delta logo]()
$360
This United Airlines deal was found by Cheapflights users on 6/19. 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.
Tue 10/275:00 am
BOI
- BMI
2 stops7h 50m
United Airlines
Sat 10/316:30 am
BMI
- BOI
1 stop6h 11m
United Airlines
Deal found 6/19![United Airlines logo]()
$424
This Southwest deal was found by Cheapflights users on 6/18. 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.
Wed 8/127:05 am
BOI
- MDW
1 stop6h 40m
Southwest
Wed 8/194:45 pm
MDW
- BOI
1 stop6h 40m
Southwest
Deal found 6/18![Southwest logo]()
$355
This Delta deal was found by Cheapflights users on 6/22. 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 8/125:30 am
BOI
- MDW
2 stops12h 03m
Delta
Wed 8/197:25 pm
MDW
- BOI
1 stop5h 34m
Delta
Deal found 6/22![Delta logo]()
$360
This Alaska Airlines deal was found by Cheapflights users on 6/22. 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 12/83:10 pm
BOI
- STL
1 stop7h 49m
Alaska Airlines
Wed 12/97:00 am
STL
- BOI
1 stop9h 05m
Alaska Airlines
Deal found 6/22![Alaska Airlines logo]()
$363
This American Airlines deal was found by Cheapflights users on 6/22. 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 7/251:57 pm
BOI
- STL
2 stops9h 01m
American Airlines
Wed 8/59:32 am
STL
- BOI
1 stop5h 59m
American Airlines
Deal found 6/22![American Airlines logo]()
$379
This Delta deal was found by Cheapflights users on 6/22. 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 9/92:11 pm
BOI
- ORD
1 stop8h 48m
Delta
Sat 9/192:05 pm
ORD
- BOI
2 stops9h 29m
Delta
Deal found 6/22![Delta logo]()
$360
This Southwest deal was found by Cheapflights users on 6/22. 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 9/1112:10 pm
BOI
- MDW
Nonstop3h 20m
Southwest
Tue 9/154:45 pm
MDW
- BOI
1 stop6h 40m
Southwest
Deal found 6/22![Southwest logo]()
$375
This Alaska Airlines deal was found by Cheapflights users on 6/20. 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.
Sun 8/237:20 am
BOI
- ORD
1 stop11h 01m
Alaska Airlines
Thu 8/278:17 pm
ORD
- BOI
1 stop18h 45m
Alaska Airlines
Deal found 6/20![Alaska Airlines logo]()
$375
This United Airlines deal was found by Cheapflights users on 6/22. 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.
Tue 10/276:59 pm
BOI
- MLI
2 stops13h 53m
United Airlines
Sat 10/318:50 am
MLI
- BOI
1 stop5h 34m
United Airlines
Deal found 6/22![United Airlines logo]()
$424
This Delta deal was found by Cheapflights users on 6/18. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/128:59 am
BOI
- ORD
2 stops11h 31m
Delta
Wed 8/192:00 pm
ORD
- BOI
2 stops9h 30m
Delta
Deal found 6/18![Delta logo]()
$365
This American Airlines deal was found by Cheapflights users on 6/22. 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.
Mon 8/103:19 pm
BOI
- MLI
1 stop7h 49m
American Airlines
Tue 8/184:32 pm
MLI
- BOI
1 stop6h 39m
American Airlines
Deal found 6/22![American Airlines logo]()
$419
This Southwest deal was found by Cheapflights users on 6/21. 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 10/214:45 pm
BOI
- MDW
1 stop6h 20m
Southwest
Sun 10/256:00 am
MDW
- BOI
1 stop5h 30m
Southwest
Deal found 6/21![Southwest logo]()
$385
This United Airlines deal was found by Cheapflights users on 6/19. 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.
Fri 7/1712:34 pm
BOI
- ORD
Nonstop3h 31m
United Airlines
Sat 7/257:45 pm
ORD
- BOI
Nonstop4h 11m
United Airlines
Deal found 6/19![United Airlines logo]()
$435
This Delta deal was found by Cheapflights users on 6/18. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/235:20 am
BOI
- MDW
1 stop6h 47m
Delta
Mon 9/287:13 pm
MDW
- BOI
1 stop5h 42m
Delta
Deal found 6/18![Delta logo]()
$385
This Alaska Airlines deal was found by Cheapflights users on 6/19. 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.
Thu 7/96:13 pm
BOI
- ORD
1 stop11h 07m
Alaska Airlines
Tue 7/146:00 am
ORD
- BOI
1 stop7h 26m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$429
This Southwest deal was found by Cheapflights users on 6/20. 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.
Wed 8/192:20 pm
BOI
- STL
1 stop7h 25m
Southwest
Mon 8/248:30 am
STL
- BOI
2 stops8h 45m
Southwest
Deal found 6/20![Southwest logo]()
$393
This American Airlines deal was found by Cheapflights users on 6/19. 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.
Sat 7/43:12 pm
BOI
- PIA
1 stop8h 03m
American Airlines
Wed 7/84:43 pm
PIA
- BOI
1 stop7h 38m
American Airlines
Deal found 6/19![American Airlines logo]()
$454
This United Airlines deal was found by Cheapflights users on 6/20. 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.
Tue 12/810:39 am
BOI
- STL
2 stops9h 34m
United Airlines
Wed 12/91:30 pm
STL
- BOI
1 stop5h 25m
United Airlines
Deal found 6/20![United Airlines logo]()
$458
This Delta deal was found by Cheapflights users on 6/20. 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.
Sun 8/911:12 am
BOI
- ORD
1 stop6h 07m
Delta
Sat 8/154:45 pm
ORD
- BOI
1 stop7h 01m
Delta
Deal found 6/20![Delta logo]()
$385
This Southwest deal was found by Cheapflights users on 6/20. 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.
Mon 7/277:40 pm
BOI
- MDW
1 stop8h 45m
Southwest
Thu 7/302:40 pm
MDW
- BOI
Nonstop3h 35m
Southwest
Deal found 6/20![Southwest logo]()
$405
This United Airlines deal was found by Cheapflights users on 6/18. 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.
Sat 8/152:44 pm
BOI
- PIA
1 stop5h 06m
United Airlines
Sat 8/2210:41 am
PIA
- BOI
2 stops12h 59m
United Airlines
Deal found 6/18![United Airlines logo]()
$469
This Delta deal was found by Cheapflights users on 6/20. 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 8/192:53 pm
BOI
- STL
1 stop7h 33m
Delta
Mon 8/245:34 pm
STL
- BOI
1 stop7h 25m
Delta
Deal found 6/20![Delta logo]()
$388
This American Airlines deal was found by Cheapflights users on 6/21. 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.
Fri 8/73:19 pm
BOI
- SPI
1 stop7h 53m
American Airlines
Fri 8/286:08 am
SPI
- BOI
2 stops11h 41m
American Airlines
Deal found 6/21![American Airlines logo]()
$512
This Southwest deal was found by Cheapflights users on 6/21. 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 7/283:00 pm
BOI
- STL
2 stops7h 45m
Southwest
Fri 8/72:20 pm
STL
- BOI
2 stops10h 35m
Southwest
Deal found 6/21![Southwest logo]()
$431
This Delta deal was found by Cheapflights users on 6/22. 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.
Tue 8/111:59 pm
BOI
- MLI
1 stop7h 20m
Delta
Tue 8/186:00 am
MLI
- BOI
1 stop7h 49m
Delta
Deal found 6/22![Delta logo]()
$394
This United Airlines deal was found by Cheapflights users on 6/21. 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 8/77:05 pm
BOI
- PIA
2 stops14h 04m
United Airlines
Fri 8/285:45 am
PIA
- BOI
2 stops10h 46m
United Airlines
Deal found 6/21![United Airlines logo]()
$495
Last-minute flights from Boise to IllinoisDiscover last-minute flight deals from Boise to Illinois. Data last updated June 23, 2026 and is based on user searches.
Discover last-minute flight deals from Boise to Illinois. Data last updated June 23, 2026 and is based on user searches.
This Alaska Airlines deal was found by Cheapflights users on 6/19. 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.
Mon 6/298:47 pm
BOI
- ORD
1 stop8h 33m
Alaska Airlines
Fri 7/38:20 pm
ORD
- BOI
1 stop14h 20m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$376
This United Airlines deal was found by Cheapflights users on 6/19. 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.
Wed 7/15:46 pm
BOI
- ORD
1 stop5h 58m
United Airlines
Sat 7/118:40 am
ORD
- BOI
Nonstop3h 52m
United Airlines
Deal found 6/19![United Airlines logo]()
$382
This Booking.com deal was found by Cheapflights users on 6/19. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/16:13 pm
BOI
- ORD
1 stop11h 07m
Alaska Airlines
Sat 7/117:17 pm
ORD
- BOI
1 stop15h 23m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$384
This CheapOair deal was found by Cheapflights users on 6/18. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/21:25 pm
BOI
- STL
1 stop28h 28m
Frontier
Wed 7/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/18![Frontier logo]()
$339
This Alaska Airlines deal was found by Cheapflights users on 6/19. 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.
Fri 7/34:27 pm
BOI
- ORD
1 stop6h 32m
Alaska Airlines
Mon 7/138:20 pm
ORD
- BOI
1 stop14h 20m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$352
This Expedia deal was found by Cheapflights users on 6/19. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/34:27 pm
BOI
- ORD
1 stop6h 32m
Alaska Airlines
Sat 7/117:17 pm
ORD
- BOI
1 stop15h 23m
Alaska Airlines
Deal found 6/19![Alaska Airlines logo]()
$362
This Booking.com deal was found by Cheapflights users on 6/18. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/34:27 pm
BOI
- ORD
1 stop6h 32m
Alaska Airlines
Fri 7/108:20 pm
ORD
- BOI
1 stop14h 20m
Alaska Airlines
Deal found 6/18![Alaska Airlines logo]()
$372
This CheapOair deal was found by Cheapflights users on 6/23. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/91:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Wed 7/158:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/23![Frontier logo]()
$306
This CheapOair deal was found by Cheapflights users on 6/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/161:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Sat 7/188:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/20![Frontier logo]()
$286
This Delta deal was found by Cheapflights users on 6/20. 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.
Tue 7/215:30 am
BOI
- MDW
1 stop6h 39m
Delta
Fri 7/247:06 pm
MDW
- BOI
1 stop5h 40m
Delta
Deal found 6/20![Delta logo]()
$385
This American Airlines deal was found by Cheapflights users on 6/22. 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 7/253:54 pm
BOI
- STL
1 stop7h 04m
American Airlines
Wed 8/59:32 am
STL
- BOI
1 stop5h 59m
American Airlines
Deal found 6/22![American Airlines logo]()
$363
This Expedia deal was found by Cheapflights users on 6/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/281:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Fri 8/77:56 pm
STL
- BOI
1 stop14h 41m
Multiple Airlines
Deal found 6/21![Multiple Airlines logo]()
$361
One-way flights from Boise to IllinoisSearch for one-way flight options from Boise to Illinois. Find affordable one-way fares based on user searches. Data last updated June 23, 2026.
Search for one-way flight options from Boise to Illinois. Find affordable one-way fares based on user searches. Data last updated June 23, 2026.
This Expedia deal was found by Cheapflights users on 6/21. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/141:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Deal found 6/21![Frontier logo]()
$122
This Frontier deal was found by Cheapflights users on 6/20. 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 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 6/20![Frontier logo]()
$125
This Frontier deal was found by Cheapflights users on 6/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/131:24 pm
BOI
- ORD
1 stop6h 28m
Frontier
Deal found 6/18![Frontier logo]()
$133
This Priceline deal was found by Cheapflights users on 6/21. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/211:24 pm
BOI
- ORD
1 stop6h 28m
Frontier
Deal found 6/21![Frontier logo]()
$135
This CheapOair deal was found by Cheapflights users on 6/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/181:24 pm
BOI
- ORD
1 stop23h 12m
Frontier
Deal found 6/20![Frontier logo]()
$136
This Frontier deal was found by Cheapflights users on 6/21. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1712:59 pm
BOI
- ORD
1 stop7h 36m
Frontier
Deal found 6/21![Frontier logo]()
$138
This Frontier deal was found by Cheapflights users on 6/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/143:52 pm
BOI
- ORD
1 stop12h 50m
Frontier
Deal found 6/18![Frontier logo]()
$139
This Kissandfly.com deal was found by Cheapflights users on 6/21. 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 Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/2312:24 pm
BOI
- ORD
1 stop24h 12m
Frontier
Deal found 6/21![Frontier logo]()
$149
This Trip.com deal was found by Cheapflights users on 6/21. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/292:17 pm
BOI
- ORD
1 stop8h 42m
Alaska Airlines
Deal found 6/21![Alaska Airlines logo]()
$150
This Alaska Airlines deal was found by Cheapflights users on 6/18. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/127:57 am
BOI
- ORD
1 stop10h 00m
Alaska Airlines
Deal found 6/18![Alaska Airlines logo]()
$153
This Frontier deal was found by Cheapflights users on 6/22. 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 7/161:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Deal found 6/22![Frontier logo]()
$154
This Alaska Airlines deal was found by Cheapflights users on 6/20. 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.
Wed 9/164:20 pm
BOI
- ORD
1 stop6h 39m
Alaska Airlines
Deal found 6/20![Alaska Airlines logo]()
$158
Find flight deals from Boise to Illinois
Keep the following information in mind while searching for Boise to Illinois flight deals. Data was last updated June 23, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $286 (CheapOair) |
One-way from | $122 (Expedia) |
Popular in | March |
Cheapest in | February |
Average price | $412 |
Good round-trip deal | $423 or less |
Good one-way deal | $279 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Boise 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 June 23, 2026.
Use the filters below to find and compare flights from Boise to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
BoiseMoline
BOI - MLI
BOIMLI
Boise Air Term. Gowen Fld
Sat 10/17
2:57 pm-11:06 pm
1 stop7h 09m
Moline Quad-City
Wed 10/21
6:22 am-12:32 pm
1 stop7h 10m
$329
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Wed 8/12
8:00 pm-1:21 pm
1 stop16h 21m
Chicago O'Hare Intl
Wed 8/19
6:01 am-2:02 pm
1 stop9h 01m
$345
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Sat 9/26
12:55 pm-8:45 pm
1 stop6h 50m
Chicago Midway
Tue 9/29
3:15 pm-11:20 pm
1 stop9h 05m
$355
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Wed 8/12
7:05 am-2:45 pm
1 stop6h 40m
Chicago Midway
Wed 8/19
4:45 pm-10:25 pm
1 stop6h 40m
$355
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Sat 9/26
5:30 am-1:20 pm
1 stop6h 50m
Chicago Midway
Tue 9/29
9:59 am-5:54 pm
2 stops8h 55m
$360
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Wed 8/12
5:30 am-6:33 pm
2 stops12h 03m
Chicago Midway
Wed 8/19
7:25 pm-11:59 pm
1 stop5h 34m
$360
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Wed 9/9
2:11 pm-11:59 pm
1 stop8h 48m
Chicago O'Hare Intl
Sat 9/19
2:05 pm-10:34 pm
2 stops9h 29m
$360
BoiseSt. Louis
BOI - STL
BOISTL
Boise Air Term. Gowen Fld
Tue 12/8
3:10 pm-11:59 pm
1 stop7h 49m
Lambert-St Louis
Wed 12/9
7:00 am-3:05 pm
1 stop9h 05m
$363
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Wed 8/12
8:59 am-9:30 pm
2 stops11h 31m
Chicago O'Hare Intl
Wed 8/19
2:00 pm-10:30 pm
2 stops9h 30m
$365
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Fri 9/11
12:10 pm-4:30 pm
Nonstop3h 20m
Chicago Midway
Tue 9/15
4:45 pm-10:25 pm
1 stop6h 40m
$375
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Boise to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Boise with our price prediction graph.
BOI-MLI
BOI-ORD
BOI-MDW
BOI-BMI
BOI-STL
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 Boise to Illinois
BOI-USIL
BOI-MLI
BOI-ORD
BOI-MDW
BOI-BMI
What is the cheapest month to book a flight from Boise to Illinois?
Currently, August is the cheapest month in which you can book a flight from Boise to Illinois (average of $115). Flying from Boise 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 BOI to IL?
Find hourly flight availability from Boise 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 June 23, 2026.
When flying from Boise to Illinois, the time of day you fly usually plays a role in the price. Save by searching for a flight at noon, which can drop the price by up to 25% versus a flight in the morning.
Weekly flight availability from Boise to Illinois
Explore weekly flight availability from Boise 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 June 23, 2026.
The most flights from BOI to USIL are scheduled on a Monday (9 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (2 on average).
How much does it cost to fly round-trip from Boise to Illinois?
How far ahead should I book a flight from Boise to Illinois?
The price you pay for your flight from Boise to Illinois may vary depending on when you book. For the best chance of a lower fare, look to book 90 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.
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 June 23, 2026.
Read through reviews of airlines operating flights from Boise to Illinois, such as Alaska Airlines,Southwest, andDelta. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Crew
8.5
Entertainment
7.0
Boarding
8.1
Comfort
7.8
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Crew
8.5
Entertainment
7.0
Boarding
8.1
Comfort
7.8
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Crew
8.5
Entertainment
7.0
Boarding
8.1
Comfort
7.8
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Crew
8.5
Entertainment
7.0
Boarding
8.1
Comfort
7.8
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Crew
8.5
Entertainment
7.0
Boarding
8.1
Comfort
7.8
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Food
7.0
Crew
8.5
Entertainment
7.0
Boarding
8.1
Comfort
7.8
Overall
7.9
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Related info for your journey
Find useful and relevant information for your journey from Boise 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 Boise 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 Boise to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Boise and Illinois flights
Browse other Boise and Illinois flight options. Last updated on June 23, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Boise to Illinois flights
Consider these flights traveling from Boise to Illinois.
Top 5 airlines flying from Boise to Illinois
Discover the top 5 airlines that operate flights from Boise 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 June 23, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$228 | Average$354 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$234 | Average$395 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$243 | Average$490 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$268 | Average$440 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$298 | Average$390 | FlexibilityNo cancel fee | On-time75% |