$114+ 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 9/2. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — ORD
Jul 9 — Jul 161
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 9, 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 9, 2026.
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/296:00 am
BOI
- STL
1 stop6h 33m
Delta
Tue 10/66:30 am
STL
- BOI
1 stop7h 12m
Delta
Deal found 6/8![Delta logo]()
$263
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/292:20 pm
BOI
- STL
1 stop7h 25m
Southwest
Tue 10/68:35 am
STL
- BOI
2 stops8h 25m
Southwest
Deal found 6/8![Southwest logo]()
$279
This Frontier deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier 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 6/6![Frontier logo]()
$289
This CheapOair deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Sat 8/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/7![Frontier logo]()
$313
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/95:40 am
BOI
- ORD
1 stop4h 49m
Delta
Wed 9/95:00 pm
ORD
- BOI
1 stop6h 56m
Delta
Deal found 6/8![Delta logo]()
$333
This CheapOair deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair 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
Mon 9/1410:40 pm
ORD
- BOI
1 stop14h 24m
Frontier
Deal found 6/7![Frontier logo]()
$334
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/87:10 am
BOI
- MDW
Nonstop3h 20m
Southwest
Tue 7/146:40 pm
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 6/8![Southwest logo]()
$335
This American Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/81:57 pm
BOI
- ORD
1 stop8h 33m
American Airlines
Tue 7/1411:30 am
ORD
- BOI
Nonstop3h 50m
American Airlines
Deal found 6/8![American Airlines logo]()
$335
This Delta deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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.
Fri 6/51:53 pm
BOI
- ORD
1 stop9h 06m
Delta
Sun 6/76:30 am
ORD
- BOI
1 stop8h 21m
Delta
Deal found 6/4![Delta logo]()
$337
This Alaska Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/78:47 pm
BOI
- ORD
1 stop8h 33m
Alaska Airlines
Wed 7/156:00 am
ORD
- BOI
1 stop7h 47m
Alaska Airlines
Deal found 6/8![Alaska Airlines logo]()
$339
This Delta deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/711:30 pm
BOI
- MLI
1 stop9h 56m
Delta
Sat 10/175:55 am
MLI
- BOI
1 stop7h 44m
Delta
Deal found 6/5![Delta logo]()
$339
This Southwest deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/155:30 am
BOI
- MDW
2 stops8h 05m
Southwest
Wed 7/226:40 pm
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 6/5![Southwest logo]()
$340
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 9, 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 9, 2026.
This CheapOair deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure 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 6/8![Frontier logo]()
$299
This Delta deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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
1 stop6h 40m
Delta
Wed 8/197:25 pm
MDW
- BOI
1 stop5h 34m
Delta
Deal found 6/4![Delta logo]()
$335
This Southwest deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/226:00 am
BOI
- MDW
1 stop6h 25m
Southwest
Tue 7/284:40 pm
MDW
- BOI
1 stop7h 20m
Southwest
Deal found 6/7![Southwest logo]()
$345
This Alaska Airlines deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/228:00 pm
BOI
- ORD
1 stop9h 20m
Alaska Airlines
Sun 10/256:00 am
ORD
- BOI
1 stop7h 35m
Alaska Airlines
Deal found 6/5![Alaska Airlines logo]()
$355
This American Airlines deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/43:12 pm
BOI
- BMI
1 stop8h 23m
American Airlines
Fri 7/104:30 pm
BMI
- BOI
1 stop7h 51m
American Airlines
Deal found 6/6![American Airlines logo]()
$429
This United Airlines deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 10/276:55 pm
BOI
- MLI
2 stops14h 19m
United Airlines
Sat 10/311:00 pm
MLI
- BOI
2 stops9h 16m
United Airlines
Deal found 6/4![United Airlines logo]()
$429
This Travelocity deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Sat 8/88:00 am
STL
- BOI
2 stops11h 11m
Multiple Airlines
Deal found 6/7![Multiple Airlines logo]()
$443
This Delta deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/71:43 pm
BOI
- MLI
1 stop7h 47m
Delta
Sat 10/175:55 am
MLI
- BOI
1 stop7h 44m
Delta
Deal found 6/6![Delta logo]()
$339
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/1410:35 am
BOI
- ORD
2 stops9h 54m
Delta
Wed 7/156:55 am
ORD
- BOI
1 stop9h 16m
Delta
Deal found 6/8![Delta logo]()
$350
This Southwest deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/1412:10 pm
BOI
- MDW
Nonstop3h 20m
Southwest
Mon 8/175:40 am
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 6/5![Southwest logo]()
$395
This Alaska Airlines deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 9/16:23 am
BOI
- STL
1 stop6h 43m
Alaska Airlines
Wed 9/26:08 pm
STL
- BOI
1 stop6h 47m
Alaska Airlines
Deal found 6/4![Alaska Airlines logo]()
$403
This Delta deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/1210:35 am
BOI
- ORD
2 stops9h 55m
Delta
Wed 8/192:00 pm
ORD
- BOI
2 stops9h 30m
Delta
Deal found 6/7![Delta logo]()
$355
This American Airlines deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/43:12 pm
BOI
- PIA
1 stop8h 03m
American Airlines
Fri 7/104:43 pm
PIA
- BOI
1 stop7h 38m
American Airlines
Deal found 6/7![American Airlines logo]()
$431
This United Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/272:43 pm
BOI
- PIA
2 stops8h 36m
United Airlines
Sat 10/318:50 am
PIA
- BOI
1 stop5h 40m
United Airlines
Deal found 6/8![United Airlines logo]()
$434
This Alaska Airlines deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/114:35 pm
BOI
- STL
1 stop6h 24m
Alaska Airlines
Tue 8/182:50 pm
STL
- BOI
1 stop7h 17m
Alaska Airlines
Deal found 6/7![Alaska Airlines logo]()
$407
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/298:20 am
BOI
- STL
1 stop5h 00m
Southwest
Tue 9/293:45 pm
STL
- BOI
2 stops8h 25m
Southwest
Deal found 6/8![Southwest logo]()
$417
This Delta deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/2510:35 am
BOI
- ORD
2 stops10h 12m
Delta
Sat 8/296:25 am
ORD
- BOI
1 stop8h 17m
Delta
Deal found 6/5![Delta logo]()
$360
This United Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/22:41 pm
BOI
- ORD
1 stop7h 38m
United Airlines
Sun 7/55:00 am
ORD
- BOI
1 stop5h 53m
United Airlines
Deal found 6/8![United Airlines logo]()
$439
This Alaska Airlines deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 6/207:57 am
BOI
- ORD
1 stop10h 40m
Alaska Airlines
Sat 6/276:00 am
ORD
- BOI
1 stop7h 47m
Alaska Airlines
Deal found 6/4![Alaska Airlines logo]()
$411
This Southwest deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 9/246:00 am
BOI
- MDW
2 stops10h 00m
Southwest
Mon 9/284:25 pm
MDW
- BOI
2 stops8h 10m
Southwest
Deal found 6/4![Southwest logo]()
$417
This Delta deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/255:30 am
BOI
- ORD
1 stop5h 07m
Delta
Tue 9/18:05 am
ORD
- BOI
2 stops10h 50m
Delta
Deal found 6/6![Delta logo]()
$360
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/61:55 pm
BOI
- STL
2 stops8h 10m
Southwest
Sun 8/96:15 am
STL
- BOI
1 stop6h 35m
Southwest
Deal found 6/8![Southwest logo]()
$420
This United Airlines deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 9/22:44 pm
BOI
- PIA
1 stop5h 06m
United Airlines
Sun 9/66:05 am
PIA
- BOI
1 stop6h 23m
United Airlines
Deal found 6/4![United Airlines logo]()
$464
This Delta deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/35:30 am
BOI
- MDW
1 stop6h 39m
Delta
Mon 7/67:16 pm
MDW
- BOI
1 stop5h 31m
Delta
Deal found 6/5![Delta logo]()
$385
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/2311:30 am
BOI
- MDW
1 stop8h 50m
Southwest
Wed 6/245:25 am
MDW
- BOI
1 stop6h 40m
Southwest
Deal found 6/8![Southwest logo]()
$433
This Delta deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/311:59 am
BOI
- ORD
1 stop5h 59m
Delta
Sun 7/56:30 am
ORD
- BOI
1 stop5h 28m
Delta
Deal found 6/6![Delta logo]()
$392
This United Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/237:05 pm
BOI
- PAH
2 stops17h 17m
United Airlines
Sat 9/265:00 am
PAH
- BOI
1 stop7h 28m
United Airlines
Deal found 6/8![United Airlines logo]()
$526
This Southwest deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/156:00 am
BOI
- STL
2 stops8h 10m
Southwest
Wed 7/225:35 am
STL
- BOI
2 stops7h 55m
Southwest
Deal found 6/4![Southwest logo]()
$441
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/216:49 am
BOI
- ORD
2 stops10h 30m
Delta
Sun 8/237:00 am
ORD
- BOI
1 stop9h 18m
Delta
Deal found 6/8![Delta logo]()
$392
This American Airlines deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 7/13:12 pm
BOI
- SPI
1 stop7h 55m
American Airlines
Sun 7/56:00 am
SPI
- BOI
1 stop9h 20m
American Airlines
Deal found 6/4![American Airlines logo]()
$709
Last-minute flights from Boise to IllinoisDiscover last-minute flight deals from Boise to Illinois. Data last updated June 9, 2026 and is based on user searches.
Discover last-minute flight deals from Boise to Illinois. Data last updated June 9, 2026 and is based on user searches.
This Booking.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 6/174:27 pm
BOI
- ORD
1 stop6h 32m
Alaska Airlines
Sat 6/206:00 am
ORD
- BOI
1 stop7h 47m
Alaska Airlines
Deal found 6/4![Alaska Airlines logo]()
$342
This Delta deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/305:30 am
BOI
- MDW
1 stop6h 39m
Delta
Sat 7/41:49 pm
MDW
- BOI
1 stop8h 23m
Delta
Deal found 6/7![Delta logo]()
$345
This Booking.com deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/14:27 pm
BOI
- STL
1 stop6h 32m
Multiple Airlines
Wed 7/88:08 pm
STL
- BOI
1 stop17h 21m
Multiple Airlines
Deal found 6/5![Multiple Airlines logo]()
$351
This Frontier deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier 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 6/6![Frontier logo]()
$289
This Booking.com deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/46:23 am
BOI
- STL
1 stop6h 29m
Multiple Airlines
Sat 7/118:08 pm
STL
- BOI
1 stop17h 21m
Multiple Airlines
Deal found 6/6![Multiple Airlines logo]()
$365
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/87:10 am
BOI
- MDW
Nonstop3h 20m
Southwest
Tue 7/146:40 pm
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 6/8![Southwest logo]()
$335
This Southwest deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 7/144:20 pm
BOI
- MDW
1 stop6h 50m
Southwest
Wed 7/156:40 pm
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 6/4![Southwest logo]()
$365
This Southwest deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/155:30 am
BOI
- MDW
2 stops8h 05m
Southwest
Wed 7/226:40 pm
MDW
- BOI
1 stop6h 50m
Southwest
Deal found 6/5![Southwest logo]()
$340
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/212:03 pm
BOI
- MDW
1 stop7h 12m
Delta
Fri 7/247:06 pm
MDW
- BOI
1 stop5h 40m
Delta
Deal found 6/8![Delta logo]()
$375
This Southwest deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/293:00 pm
BOI
- MDW
1 stop7h 45m
Southwest
Mon 8/32:40 pm
MDW
- BOI
Nonstop3h 35m
Southwest
Deal found 6/7![Southwest logo]()
$382
This CheapOair deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Sat 8/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/7![Frontier logo]()
$313
This Travelocity deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Sun 8/96:02 am
STL
- BOI
1 stop9h 05m
Multiple Airlines
Deal found 6/5![Multiple Airlines logo]()
$388
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 9, 2026.
Search for one-way flight options from Boise to Illinois. Find affordable one-way fares based on user searches. Data last updated June 9, 2026.
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/25:30 am
BOI
- MDW
1 stop6h 40m
Delta
Deal found 6/8![Delta logo]()
$114
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/43:29 pm
BOI
- ORD
1 stop7h 00m
Delta
Deal found 6/8![Delta logo]()
$114
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/27:30 pm
BOI
- MDW
2 stops12h 19m
Delta
Deal found 6/8![Delta logo]()
$119
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/26:49 am
BOI
- ORD
2 stops10h 30m
Delta
Deal found 6/8![Delta logo]()
$119
This Kiwi.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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 9/81:04 pm
BOI
- ORD
1 stop6h 49m
Frontier
Deal found 6/4![Frontier logo]()
$124
This American Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/53:21 pm
BOI
- ORD
Nonstop3h 51m
American Airlines
Deal found 6/8![American Airlines logo]()
$126
This Trip.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” 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.
Tue 9/11:04 pm
BOI
- ORD
1 stop6h 49m
Frontier
Deal found 6/4![Frontier logo]()
$130
This Frontier deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier 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
Deal found 6/8![Frontier logo]()
$135
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/85:30 am
BOI
- MDW
1 stop6h 40m
Delta
Deal found 6/8![Delta logo]()
$136
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/81:06 pm
BOI
- ORD
1 stop7h 24m
Delta
Deal found 6/8![Delta logo]()
$136
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/55:40 am
BOI
- MDW
2 stops11h 57m
Delta
Deal found 6/8![Delta logo]()
$141
This Delta deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/510:58 am
BOI
- ORD
2 stops9h 49m
Delta
Deal found 6/8![Delta logo]()
$141
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 9, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $263 (Delta) |
One-way from | $114 (Delta) |
Popular in | March |
Cheapest in | February |
Average price | $401 |
Good round-trip deal | $417 or less |
Good one-way deal | $236 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 9, 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
BoiseSt. Louis
BOI - STL
BOISTL
Boise Air Term. Gowen Fld
Thu 7/2
1:25 pm-6:53 pm
1 stop28h 28m
Lambert-St Louis
Wed 7/8
8:08 pm-12:29 pm
1 stop17h 21m
$299
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Wed 8/12
5:30 am-1:10 pm
1 stop6h 40m
Chicago Midway
Wed 8/19
7:25 pm-11:59 pm
1 stop5h 34m
$335
BoiseMoline
BOI - MLI
BOIMLI
Boise Air Term. Gowen Fld
Wed 10/7
1:43 pm-10:30 pm
1 stop7h 47m
Moline Quad-City
Sat 10/17
5:55 am-12:39 pm
1 stop7h 44m
$339
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Wed 7/22
6:00 am-1:25 pm
1 stop6h 25m
Chicago Midway
Tue 7/28
4:40 pm-11:00 pm
1 stop7h 20m
$345
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Tue 7/14
10:35 am-9:29 pm
2 stops9h 54m
Chicago O'Hare Intl
Wed 7/15
6:55 am-3:11 pm
1 stop9h 16m
$350
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Thu 10/22
8:00 pm-6:20 am
1 stop9h 20m
Chicago O'Hare Intl
Sun 10/25
6:00 am-12:35 pm
1 stop7h 35m
$355
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Wed 8/12
10:35 am-9:30 pm
2 stops9h 55m
Chicago O'Hare Intl
Wed 8/19
2:00 pm-10:30 pm
2 stops9h 30m
$355
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Tue 8/25
10:35 am-9:47 pm
2 stops10h 12m
Chicago O'Hare Intl
Sat 8/29
6:25 am-1:42 pm
1 stop8h 17m
$360
BoiseChicago
BOI - ORD
BOIORD
Boise Air Term. Gowen Fld
Tue 8/25
5:30 am-11:37 am
1 stop5h 07m
Chicago O'Hare Intl
Tue 9/1
8:05 am-5:55 pm
2 stops10h 50m
$360
BoiseChicago
BOI - MDW
BOIMDW
Boise Air Term. Gowen Fld
Fri 7/3
5:30 am-1:09 pm
1 stop6h 39m
Chicago Midway
Mon 7/6
7:16 pm-11:47 pm
1 stop5h 31m
$385
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-STL
BOI-MDW
BOI-ORD
BOI-BMI
BOI-MLI
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-STL
BOI-MDW
BOI-ORD
BOI-BMI
What is the cheapest month to book a flight from Boise to Illinois?
Currently, July is the cheapest month in which you can book a flight from Boise to Illinois (average of $87). 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 9, 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 38% versus a flight in the evening.
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 9, 2026.
The most flights from BOI to USIL are scheduled on a Monday (9 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (9 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 9, 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.
Comfort
7.8
Food
7.1
Overall
7.9
Entertainment
7.0
Crew
8.5
Boarding
8.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Comfort
7.8
Food
7.1
Overall
7.9
Entertainment
7.0
Crew
8.5
Boarding
8.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Comfort
7.8
Food
7.1
Overall
7.9
Entertainment
7.0
Crew
8.5
Boarding
8.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Comfort
7.8
Food
7.1
Overall
7.9
Entertainment
7.0
Crew
8.5
Boarding
8.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Comfort
7.8
Food
7.1
Overall
7.9
Entertainment
7.0
Crew
8.5
Boarding
8.1
Reviews
1 / 20
4.0
OkayAnonymous,Jun 2026
SEA - RNO
Comfort
7.8
Food
7.1
Overall
7.9
Entertainment
7.0
Crew
8.5
Boarding
8.1
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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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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Boise and Illinois flights
Browse other Boise and Illinois flight options. Last updated on June 9, 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 9, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$168 | Average$347 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$224 | Average$382 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$234 | Average$394 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$239 | Average$481 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$269 | Average$380 | FlexibilityNo cancel fee | On-time71% |