$92+ Cheap flights from Illinois to Idaho
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 5/9. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — BOI
May 2 — May 91
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
Find cheap flights from Illinois to Idaho with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Illinois to Idaho
Cheapest
Best
Last-minute
One-way
Cheapest flights from Illinois to IdahoExplore the most affordable flight options available from Illinois to Idaho. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 2, 2026.
Explore the most affordable flight options available from Illinois to Idaho. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 2, 2026.
This CheapOair deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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.
Wed 6/248:08 pm
STL
- BOI
1 stop17h 01m
Frontier
Tue 6/301:04 pm
BOI
- STL
1 stop5h 19m
Frontier
Deal found 3/29![Frontier logo]()
$241
This CheapOair deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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.
Wed 4/83:29 pm
ORD
- BOI
1 stop20h 39m
Frontier
Sun 4/1212:03 pm
BOI
- ORD
1 stop24h 16m
Frontier
Deal found 3/31![Frontier logo]()
$263
This Expedia deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/63:52 pm
ORD
- GEG
1 stop8h 28m
Multiple Airlines
Wed 5/1312:33 pm
GEG
- ORD
1 stop5h 59m
Multiple Airlines
Deal found 4/1![Multiple Airlines logo]()
$269
This Expedia deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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 5/96:00 am
ORD
- BOI
1 stop7h 35m
Multiple Airlines
Sun 5/101:22 pm
BOI
- ORD
1 stop6h 15m
Multiple Airlines
Deal found 3/30![Multiple Airlines logo]()
$288
This Expedia deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 5/56:00 am
ORD
- BOI
1 stop7h 35m
Multiple Airlines
Tue 5/121:22 pm
BOI
- ORD
1 stop6h 15m
Multiple Airlines
Deal found 3/29![Multiple Airlines logo]()
$293
This Expedia deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 5/202:10 pm
ORD
- GEG
1 stop9h 35m
Multiple Airlines
Wed 5/2712:33 pm
GEG
- ORD
1 stop6h 04m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$293
This Expedia deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 4/298:48 pm
ORD
- GEG
1 stop14h 13m
Multiple Airlines
Wed 5/612:33 pm
GEG
- ORD
1 stop6h 04m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$294
This Alaska Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/56:00 am
ORD
- BOI
1 stop7h 35m
Alaska Airlines
Sat 5/97:43 am
BOI
- ORD
1 stop10h 20m
Alaska Airlines
Deal found 4/1![Alaska Airlines logo]()
$295
This Alaska Airlines deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 5/282:10 pm
ORD
- GEG
1 stop9h 35m
Alaska Airlines
Sat 5/307:01 am
GEG
- ORD
1 stop9h 49m
Alaska Airlines
Deal found 3/28![Alaska Airlines logo]()
$295
This Alaska Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 4/285:52 pm
ORD
- BOI
1 stop7h 07m
Alaska Airlines
Wed 4/295:56 pm
BOI
- ORD
1 stop28h 47m
Alaska Airlines
Deal found 4/1![Alaska Airlines logo]()
$296
This Alaska Airlines deal was found by Cheapflights users on 4/2. Clicking the “Pick Dates” 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 4/237:59 pm
ORD
- BOI
1 stop17h 33m
Alaska Airlines
Sat 4/257:43 am
BOI
- ORD
1 stop10h 20m
Alaska Airlines
Deal found 4/2![Alaska Airlines logo]()
$297
This American Airlines deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 4/2810:30 am
ORD
- GEG
Nonstop4h 02m
American Airlines
Tue 5/51:22 pm
GEG
- ORD
Nonstop3h 57m
American Airlines
Deal found 3/31![American Airlines logo]()
$297
Best flights from Illinois to IdahoDiscover carefully curated flight deals from Illinois to Idaho that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 2, 2026.
Discover carefully curated flight deals from Illinois to Idaho that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 2, 2026.
This Alaska Airlines deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 5/27:00 am
STL
- BOI
1 stop9h 33m
Alaska Airlines
Tue 5/52:57 pm
BOI
- STL
1 stop8h 02m
Alaska Airlines
Deal found 3/28![Alaska Airlines logo]()
$317
This Southwest deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/294:00 pm
MDW
- GEG
2 stops9h 25m
Southwest
Wed 5/62:25 pm
GEG
- MDW
1 stop6h 55m
Southwest
Deal found 3/31![Southwest logo]()
$322
This United Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 6/25:00 am
ORD
- IDA
1 stop5h 50m
United Airlines
Sat 6/62:30 pm
IDA
- ORD
1 stop6h 09m
United Airlines
Deal found 4/1![United Airlines logo]()
$329
This Delta deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 6/106:55 am
ORD
- GEG
1 stop6h 57m
Delta
Tue 6/165:20 am
GEG
- ORD
1 stop6h 10m
Delta
Deal found 3/28![Delta logo]()
$335
This Expedia deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 4/304:46 pm
STL
- GEG
2 stops17h 05m
Multiple Airlines
Sun 5/311:44 am
GEG
- STL
1 stop5h 37m
Multiple Airlines
Deal found 4/1![Multiple Airlines logo]()
$472
This American Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 6/2911:02 am
ORD
- IDA
Nonstop3h 42m
American Airlines
Tue 7/712:29 pm
IDA
- ORD
Nonstop3h 30m
American Airlines
Deal found 4/1![American Airlines logo]()
$480
This Delta deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 9/239:20 am
MDW
- GEG
1 stop5h 47m
Delta
Wed 9/306:05 am
GEG
- MDW
1 stop5h 06m
Delta
Deal found 4/1![Delta logo]()
$335
This Southwest deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/26:00 am
MDW
- GEG
1 stop6h 05m
Southwest
Sat 5/96:15 am
GEG
- MDW
2 stops9h 00m
Southwest
Deal found 3/28![Southwest logo]()
$340
This United Airlines deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 7/38:40 am
ORD
- BOI
Nonstop3h 52m
United Airlines
Tue 7/77:05 pm
BOI
- ORD
1 stop8h 56m
United Airlines
Deal found 3/29![United Airlines logo]()
$345
This Alaska Airlines deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 5/23:52 pm
ORD
- GEG
1 stop8h 28m
Alaska Airlines
Tue 5/52:45 pm
GEG
- ORD
1 stop7h 14m
Alaska Airlines
Deal found 3/29![Alaska Airlines logo]()
$345
This Delta deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 5/237:13 pm
MDW
- BOI
1 stop5h 33m
Delta
Wed 5/279:16 pm
BOI
- MDW
2 stops10h 26m
Delta
Deal found 3/28![Delta logo]()
$340
This Southwest deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/304:35 pm
MDW
- GEG
2 stops9h 55m
Southwest
Thu 5/71:30 pm
GEG
- MDW
1 stop8h 25m
Southwest
Deal found 4/1![Southwest logo]()
$340
This United Airlines deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 6/75:00 am
ORD
- JAC
1 stop5h 46m
United Airlines
Wed 6/104:23 pm
JAC
- ORD
1 stop5h 26m
United Airlines
Deal found 3/29![United Airlines logo]()
$364
This Delta deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 5/77:12 am
ORD
- GEG
1 stop7h 01m
Delta
Tue 5/126:49 am
GEG
- ORD
2 stops9h 52m
Delta
Deal found 3/29![Delta logo]()
$340
This Southwest deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/292:55 pm
MDW
- GEG
1 stop10h 00m
Southwest
Sun 5/312:05 pm
GEG
- MDW
1 stop10h 45m
Southwest
Deal found 3/30![Southwest logo]()
$351
This Alaska Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/94:46 pm
STL
- GEG
1 stop6h 45m
Alaska Airlines
Wed 5/1312:46 pm
GEG
- STL
1 stop9h 08m
Alaska Airlines
Deal found 4/1![Alaska Airlines logo]()
$387
This Delta deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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 8/221:35 pm
ORD
- GEG
2 stops12h 09m
Delta
Sat 8/296:30 am
GEG
- ORD
1 stop9h 00m
Delta
Deal found 3/30![Delta logo]()
$340
This United Airlines deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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 4/148:54 am
STL
- JAC
1 stop5h 27m
United Airlines
Thu 4/232:35 pm
JAC
- STL
1 stop5h 19m
United Airlines
Deal found 3/30![United Airlines logo]()
$378
This Southwest deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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 5/16:40 am
MDW
- BOI
1 stop10h 00m
Southwest
Tue 5/56:40 am
BOI
- MDW
1 stop6h 20m
Southwest
Deal found 3/30![Southwest logo]()
$355
This Delta deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 5/26:25 am
ORD
- GEG
1 stop8h 39m
Delta
Tue 5/510:40 pm
GEG
- ORD
2 stops12h 05m
Delta
Deal found 3/29![Delta logo]()
$340
This American Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 6/210:56 am
ORD
- IDA
Nonstop3h 42m
American Airlines
Sat 6/612:44 pm
IDA
- ORD
Nonstop3h 27m
American Airlines
Deal found 4/1![American Airlines logo]()
$505
This Southwest deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 6/245:25 am
MDW
- BOI
1 stop6h 40m
Southwest
Tue 6/304:20 pm
BOI
- MDW
1 stop6h 45m
Southwest
Deal found 3/28![Southwest logo]()
$355
This Delta deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 9/2312:40 pm
ORD
- GEG
1 stop8h 07m
Delta
Wed 9/305:20 am
GEG
- ORD
2 stops10h 41m
Delta
Deal found 4/1![Delta logo]()
$340
This United Airlines deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 5/210:25 am
STL
- BOI
2 stops11h 52m
United Airlines
Tue 5/52:26 pm
BOI
- STL
1 stop5h 17m
United Airlines
Deal found 3/29![United Airlines logo]()
$412
This Alaska Airlines deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 4/158:00 am
ORD
- IDA
1 stop9h 19m
Alaska Airlines
Sun 4/196:00 am
IDA
- ORD
1 stop8h 13m
Alaska Airlines
Deal found 3/31![Alaska Airlines logo]()
$464
This Southwest deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 9/257:10 am
MDW
- GEG
1 stop8h 05m
Southwest
Tue 9/297:00 am
GEG
- MDW
2 stops7h 00m
Southwest
Deal found 3/28![Southwest logo]()
$360
This Delta deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/237:13 pm
MDW
- GEG
1 stop5h 53m
Delta
Sat 5/306:49 am
GEG
- MDW
2 stops12h 20m
Delta
Deal found 4/1![Delta logo]()
$340
This United Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 4/284:30 pm
STL
- BOI
1 stop5h 52m
United Airlines
Wed 4/292:37 pm
BOI
- STL
1 stop5h 17m
United Airlines
Deal found 4/1![United Airlines logo]()
$417
This Alaska Airlines deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 4/136:00 am
ORD
- IDA
1 stop11h 19m
Alaska Airlines
Fri 4/174:59 pm
IDA
- ORD
1 stop21h 14m
Alaska Airlines
Deal found 3/29![Alaska Airlines logo]()
$464
This Southwest deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 6/262:40 pm
MDW
- BOI
Nonstop3h 35m
Southwest
Sun 6/288:20 pm
BOI
- MDW
1 stop7h 40m
Southwest
Deal found 3/29![Southwest logo]()
$365
Last-minute flights from Illinois to IdahoDiscover last-minute flight deals from Illinois to Idaho. Data last updated April 2, 2026 and is based on user searches.
Discover last-minute flight deals from Illinois to Idaho. Data last updated April 2, 2026 and is based on user searches.
This CheapOair deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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.
Wed 4/83:29 pm
ORD
- BOI
1 stop20h 39m
Frontier
Sun 4/1212:03 pm
BOI
- ORD
1 stop24h 16m
Frontier
Deal found 3/31![Frontier logo]()
$263
This Alaska Airlines deal was found by Cheapflights users on 4/2. Clicking the “Pick Dates” 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 4/237:59 pm
ORD
- BOI
1 stop17h 33m
Alaska Airlines
Sat 4/257:43 am
BOI
- ORD
1 stop10h 20m
Alaska Airlines
Deal found 4/2![Alaska Airlines logo]()
$297
This Alaska Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 4/285:52 pm
ORD
- BOI
1 stop7h 07m
Alaska Airlines
Wed 4/295:56 pm
BOI
- ORD
1 stop28h 47m
Alaska Airlines
Deal found 4/1![Alaska Airlines logo]()
$296
This American Airlines deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 4/2810:30 am
ORD
- GEG
Nonstop4h 02m
American Airlines
Tue 5/51:22 pm
GEG
- ORD
Nonstop3h 57m
American Airlines
Deal found 3/31![American Airlines logo]()
$297
This Expedia deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 4/298:48 pm
ORD
- GEG
1 stop14h 13m
Multiple Airlines
Wed 5/612:33 pm
GEG
- ORD
1 stop6h 04m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$294
This Expedia deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 5/56:00 am
ORD
- BOI
1 stop7h 35m
Multiple Airlines
Tue 5/121:22 pm
BOI
- ORD
1 stop6h 15m
Multiple Airlines
Deal found 3/29![Multiple Airlines logo]()
$293
This Alaska Airlines deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/56:00 am
ORD
- BOI
1 stop7h 35m
Alaska Airlines
Sat 5/97:43 am
BOI
- ORD
1 stop10h 20m
Alaska Airlines
Deal found 4/1![Alaska Airlines logo]()
$295
This Expedia deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/63:52 pm
ORD
- GEG
1 stop8h 28m
Multiple Airlines
Wed 5/1312:33 pm
GEG
- ORD
1 stop5h 59m
Multiple Airlines
Deal found 4/1![Multiple Airlines logo]()
$269
This Expedia deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 5/88:48 pm
ORD
- BOI
1 stop13h 54m
Multiple Airlines
Sun 5/101:22 pm
BOI
- ORD
1 stop6h 15m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$298
This Expedia deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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 5/96:00 am
ORD
- BOI
1 stop7h 35m
Multiple Airlines
Sun 5/101:22 pm
BOI
- ORD
1 stop6h 15m
Multiple Airlines
Deal found 3/30![Multiple Airlines logo]()
$288
This Expedia deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 5/202:10 pm
ORD
- GEG
1 stop9h 35m
Multiple Airlines
Wed 5/2712:33 pm
GEG
- ORD
1 stop6h 04m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$293
This Alaska Airlines deal was found by Cheapflights users on 3/28. Clicking the “Pick Dates” 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 5/282:10 pm
ORD
- GEG
1 stop9h 35m
Alaska Airlines
Sat 5/307:01 am
GEG
- ORD
1 stop9h 49m
Alaska Airlines
Deal found 3/28![Alaska Airlines logo]()
$295
One-way flights from Illinois to IdahoSearch for one-way flight options from Illinois to Idaho. Find affordable one-way fares based on user searches. Data last updated April 2, 2026.
Search for one-way flight options from Illinois to Idaho. Find affordable one-way fares based on user searches. Data last updated April 2, 2026.
This CheapOair deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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.
Sat 5/99:42 pm
ORD
- BOI
1 stop15h 45m
Frontier
Deal found 3/30![Frontier logo]()
$92
This Kiwi.com deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/287:21 pm
ORD
- GEG
2 stops51h 08m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$119
This Kiwi.com deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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.
Wed 4/298:58 pm
ORD
- GEG
1 stop25h 31m
Multiple Airlines
Deal found 3/31![Multiple Airlines logo]()
$122
This Kiwi.com deal was found by Cheapflights users on 4/2. Clicking the “Pick Dates” 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.
Wed 6/39:37 pm
ORD
- BOI
1 stop15h 53m
Frontier
Deal found 4/2![Frontier logo]()
$127
This Kiwi.com deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 5/259:37 pm
ORD
- BOI
1 stop15h 53m
Frontier
Deal found 4/1![Frontier logo]()
$131
This Kiwi.com deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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 4/308:58 pm
ORD
- IDA
1 stop19h 29m
Multiple Airlines
Deal found 3/29![Multiple Airlines logo]()
$137
This CheapOair deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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.
Mon 6/89:42 pm
ORD
- BOI
1 stop15h 27m
Frontier
Deal found 3/29![Frontier logo]()
$137
This CheapOair deal was found by Cheapflights users on 3/29. Clicking the “Pick Dates” 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.
Wed 4/83:29 pm
ORD
- BOI
1 stop20h 39m
Frontier
Deal found 3/29![Frontier logo]()
$138
This Kiwi.com deal was found by Cheapflights users on 3/30. Clicking the “Pick Dates” 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 5/59:42 pm
ORD
- GEG
2 stops48h 47m
Multiple Airlines
Deal found 3/30![Multiple Airlines logo]()
$138
This Kiwi.com deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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.
Wed 4/296:10 am
MDW
- GEG
2 stops40h 19m
Multiple Airlines
Deal found 4/1![Multiple Airlines logo]()
$141
This Kiwi.com deal was found by Cheapflights users on 4/1. Clicking the “Pick Dates” 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 6/29:37 pm
ORD
- GEG
1 stop16h 01m
Frontier
Deal found 4/1![Frontier logo]()
$147
This Alaska Airlines deal was found by Cheapflights users on 3/31. Clicking the “Pick Dates” 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 4/295:52 pm
ORD
- BOI
1 stop7h 07m
Alaska Airlines
Deal found 3/31![Alaska Airlines logo]()
$148
Find flight deals from Illinois to Idaho
Keep the following information in mind while searching for Illinois to Idaho flight deals. Data was last updated April 2, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $241 (CheapOair) |
One-way from | $92 (CheapOair) |
Popular in | June |
Cheapest in | February |
Average price | $363 |
Good round-trip deal | $344 or less |
Good one-way deal | $209 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Illinois to Idaho 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 2, 2026.
Use the filters below to find and compare flights from Illinois to Idaho that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Sat 5/2
7:00 am-3:33 pm
1 stop9h 33m
Boise Air Term. Gowen Fld
Tue 5/5
2:57 pm-11:59 pm
1 stop8h 02m
$317
ChicagoSpokane
MDW - GEG
MDWGEG
Chicago Midway
Wed 4/29
4:00 pm-11:25 pm
2 stops9h 25m
Spokane
Wed 5/6
2:25 pm-11:20 pm
1 stop6h 55m
$322
ChicagoIdaho Falls
ORD - IDA
ORDIDA
Chicago O'Hare Intl
Tue 6/2
5:00 am-9:50 am
1 stop5h 50m
Idaho Falls Fanning Field
Sat 6/6
2:30 pm-9:39 pm
1 stop6h 09m
$329
ChicagoSpokane
ORD - GEG
ORDGEG
Chicago O'Hare Intl
Wed 6/10
6:55 am-11:52 am
1 stop6h 57m
Spokane
Tue 6/16
5:20 am-1:30 pm
1 stop6h 10m
$335
ChicagoSpokane
MDW - GEG
MDWGEG
Chicago Midway
Wed 9/23
9:20 am-1:07 pm
1 stop5h 47m
Spokane
Wed 9/30
6:05 am-1:11 pm
1 stop5h 06m
$335
ChicagoSpokane
MDW - GEG
MDWGEG
Chicago Midway
Sat 5/2
6:00 am-10:05 am
1 stop6h 05m
Spokane
Sat 5/9
6:15 am-5:15 pm
2 stops9h 00m
$340
ChicagoBoise
MDW - BOI
MDWBOI
Chicago Midway
Sat 5/23
7:13 pm-11:46 pm
1 stop5h 33m
Boise Air Term. Gowen Fld
Wed 5/27
9:16 pm-8:42 am
2 stops10h 26m
$340
ChicagoSpokane
MDW - GEG
MDWGEG
Chicago Midway
Thu 4/30
4:35 pm-12:30 am
2 stops9h 55m
Spokane
Thu 5/7
1:30 pm-11:55 pm
1 stop8h 25m
$340
ChicagoSpokane
ORD - GEG
ORDGEG
Chicago O'Hare Intl
Thu 5/7
7:12 am-12:13 pm
1 stop7h 01m
Spokane
Tue 5/12
6:49 am-6:41 pm
2 stops9h 52m
$340
ChicagoSpokane
ORD - GEG
ORDGEG
Chicago O'Hare Intl
Sat 8/22
1:35 pm-11:44 pm
2 stops12h 09m
Spokane
Sat 8/29
6:30 am-5:30 pm
1 stop9h 00m
$340
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Illinois to Idaho
Have a flexible travel schedule? Discover the best time to fly to Idaho from Illinois with our price prediction graph.
STL-BOI
MDW-GEG
ORD-IDA
ORD-GEG
STL-GEG
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 Illinois to Idaho
USIL-USID
STL-BOI
MDW-GEG
ORD-IDA
ORD-GEG
What is the cheapest month to book a flight from Illinois to Idaho?
Currently, September is the cheapest month in which you can book a flight from Illinois to Idaho (average of $161). Flying from Illinois to Idaho in March is currently the most expensive (average of $393). 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 IL to ID?
Find hourly flight availability from Illinois to Idaho. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 2, 2026.
It’s typically best to fly out from Illinois to Idaho at noon. Doing so could potentially save you 27% on the flight price compared to flying in the afternoon, which is usually more expensive.
Weekly flight availability from Illinois to Idaho
Explore weekly flight availability from Illinois to Idaho. 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 2, 2026.
The most flights from USIL to USID are scheduled on a Monday (7 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (3 on average).
How much does it cost to fly round-trip from Illinois to Idaho?
Reviews of airlines servicing Idaho
Get insights into the airlines that provide service to Idaho. 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 Idaho. Reviews last updated April 2, 2026.
Read reviews from past customers who have flown Southwest,Alaska Airlines, andDelta from Illinois to Idaho. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Overall
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Overall
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Overall
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Overall
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Overall
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Overall
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Related info for your journey
Find useful and relevant information for your journey from Illinois to Idaho. 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
Flights by cabin class
Other flight options
Popular flights
Return Flight Options
Top destinations
Alternative routes for Illinois to Idaho
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Idaho by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Illinois to Idaho by cabin class
Find flights from Illinois to Idaho, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Illinois and Idaho flights
Browse other Illinois and Idaho flight options. Last updated on April 2, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Find a return flight route from Idaho
Find the right flight back to Illinois after your stay in Idaho
Illinois to Idaho flights
Consider these flights traveling from Illinois to Idaho.
Top 4 airlines flying from Illinois to Idaho
Discover the top 4 airlines that operate flights from Illinois to Idaho. 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 2, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$174 | Average$337 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$237 | Average$458 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$254 | Average$378 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$268 | Average$464 | FlexibilityNo cancel fee | On-time71% |