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$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 2/28. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — BOI
Feb 28 — Mar 71
Sat 2/28
Sat 3/7
1 adult, Economy
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Cheap flight deals from Illinois to Idaho

Cheapest flights from Illinois to Idaho
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 January 29, 2026.

This Expedia deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 2/245:29 pm
ORD
-
GEG
1 stop8h 30m
Multiple Airlines
Thu 2/2612:22 pm
GEG
-
ORD
1 stop8h 52m
Multiple Airlines
Deal found 1/27$193
This Kiwi.com deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 2/2610:11 pm
STL
-
BOI
2 stops14h 00m
Frontier
Thu 3/512:38 pm
BOI
-
STL
1 stop20h 11m
Frontier
Deal found 1/27$197
This Trip.com deal was found by Cheapflights users on 1/26. Clicking the “Pick Dates” 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.
Wed 2/43:46 pm
STL
-
GEG
1 stop21h 22m
Frontier
Sun 2/812:03 pm
GEG
-
STL
1 stop22h 47m
Frontier
Deal found 1/26$211
This Kiwi.com deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 3/188:12 pm
STL
-
BOI
1 stop16h 08m
Frontier
Sun 3/2212:15 pm
BOI
-
STL
1 stop20h 34m
Frontier
Deal found 1/27$220
This Kiwi.com deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 2/1811:51 am
ORD
-
BOI
2 stops25h 00m
Frontier
Thu 3/512:38 pm
BOI
-
ORD
1 stop9h 36m
Frontier
Deal found 1/27$223
This Travelocity deal was found by Cheapflights users on 1/28. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 2/257:00 am
ORD
-
BOI
1 stop8h 58m
Alaska Airlines
Wed 3/45:40 am
BOI
-
ORD
1 stop6h 31m
Alaska Airlines
Deal found 1/28$229
This Expedia deal was found by Cheapflights users on 1/28. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/178:20 am
ORD
-
BOI
1 stop16h 10m
Multiple Airlines
Thu 2/1912:36 pm
BOI
-
ORD
1 stop9h 38m
Multiple Airlines
Deal found 1/28$230
This Kiwi.com deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 3/26:00 am
ORD
-
BOI
1 stop11h 47m
Multiple Airlines
Thu 3/512:38 pm
BOI
-
ORD
1 stop9h 36m
Multiple Airlines
Deal found 1/27$232
This Alaska Airlines deal was found by Cheapflights users on 1/28. 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.
Wed 3/45:29 pm
ORD
-
GEG
1 stop8h 30m
Alaska Airlines
Wed 3/115:40 am
GEG
-
ORD
1 stop6h 31m
Alaska Airlines
Deal found 1/28$235
This Delta deal was found by Cheapflights users on 1/28. 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.
Tue 3/313:05 pm
STL
-
BOI
1 stop7h 04m
Delta
Sat 4/45:30 am
BOI
-
STL
1 stop5h 18m
Delta
Deal found 1/28$237
This Kiwi.com deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 2/1811:51 am
ORD
-
BOI
2 stops25h 00m
Multiple Airlines
Mon 3/25:37 pm
BOI
-
ORD
1 stop23h 31m
Multiple Airlines
Deal found 1/27$243
This Kiwi.com deal was found by Cheapflights users on 1/27. Clicking the “Pick Dates” 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 2/1811:51 am
ORD
-
BOI
2 stops25h 00m
Multiple Airlines
Fri 2/275:37 pm
BOI
-
ORD
1 stop22h 16m
Multiple Airlines
Deal found 1/27$247

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 January 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$193
(Expedia)

One-way from

$92
(Kiwi.com)

Popular in

November

Cheapest in

September

Average price

$383

Good round-trip deal

$326 or less

Good one-way deal

$245 or less
Provider with most accurate pricing for Chicago (CHI)-Boise Air Term. Gowen Fld flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-Boise Air Term. Gowen Fld flights.
Search Deals
From Illinois to Idaho
Search Deals
One-way flight from Illinois to Idaho
Search Deals
Highest demand for flights based on searches. 2% potential increase in price ($10 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals
Price to beat on a round-trip flight from Illinois to Idaho.
Search Deals
Price to beat on a one-way flight from Illinois to Idaho.
Search Deals

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 January 29, 2026.
Use the filters below to find and compare flights from Illinois to Idaho that are best for you.

Fly from

Illinois

Fly to

Idaho

Route

Depart

Return

Price

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Tue 3/31

4:30 pm-9:22 pm

1 stop5h 52m

Boise Air Term. Gowen Fld

Sat 4/4

2:37 pm-8:54 pm

1 stop5h 17m

$237

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Tue 3/31

3:05 pm-9:09 pm

1 stop7h 04m

Boise Air Term. Gowen Fld

Sat 4/4

5:30 am-11:48 am

1 stop5h 18m

$237

ChicagoBoise

ORD - BOI

ORDBOI

Chicago O'Hare Intl

Mon 5/4

7:59 pm-12:32 pm

1 stop17h 33m

Boise Air Term. Gowen Fld

Wed 5/6

2:57 pm-11:59 pm

1 stop8h 02m

$249

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Wed 3/25

2:12 pm-7:02 pm

1 stop5h 50m

Jackson Hole

Mon 3/30

5:50 pm-12:21 am

1 stop5h 31m

$257

ChicagoBoise

ORD - BOI

ORDBOI

Chicago O'Hare Intl

Sat 2/28

9:15 am-12:33 pm

Nonstop4h 18m

Boise Air Term. Gowen Fld

Sat 3/7

2:40 pm-10:55 pm

1 stop7h 15m

$259

ChicagoBoise

ORD - BOI

ORDBOI

Chicago O'Hare Intl

Wed 3/4

9:15 am-12:33 pm

Nonstop4h 18m

Boise Air Term. Gowen Fld

Tue 3/10

5:31 pm-11:52 pm

1 stop5h 21m

$259

ChicagoBoise

ORD - BOI

ORDBOI

Chicago O'Hare Intl

Sat 4/18

8:40 am-11:49 am

Nonstop4h 09m

Boise Air Term. Gowen Fld

Sat 4/25

2:37 pm-10:58 pm

1 stop7h 21m

$259

ChicagoBoise

ORD - BOI

ORDBOI

Chicago O'Hare Intl

Mon 3/9

7:40 pm-10:56 pm

Nonstop4h 16m

Boise Air Term. Gowen Fld

Wed 3/18

5:00 am-11:19 am

1 stop5h 19m

$259

ChicagoSpokane

ORD - GEG

ORDGEG

Chicago O'Hare Intl

Sat 2/28

2:40 pm-9:17 pm

1 stop8h 37m

Spokane

Tue 3/3

7:00 am-12:50 pm

Nonstop3h 50m

$265

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Thu 2/26

2:47 pm-12:24 pm

2 stops22h 37m

Jackson Hole

Thu 3/5

11:48 am-1:51 pm

2 stops25h 03m

$267

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/28

Showing 1-10 of 60 results
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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.
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

What is the cheapest month to book a flight from Illinois to Idaho?

Currently, July is the cheapest month in which you can book a flight from Illinois to Idaho (average of $149). Flying from Illinois to Idaho in December is currently the most expensive (average of $288). 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 January 29, 2026.

It’s typically best to fly out from Illinois to Idaho at noon. Doing so could potentially save you 19% 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 January 29, 2026.

The most flights from USIL to USID are scheduled on a Thursday (6 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (2 on average).

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 January 29, 2026.
Read reviews from past customers who have flown Alaska Airlines, Southwest, and Delta from Illinois to Idaho. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
11,806 reviews

Overall

8.0

Entertainment

7.0

Food

7.1

Crew

8.5

Boarding

8.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
Alaska Airlines
8.0
Very good
11,806 reviews
Alaska Airlines
8.0
Very good
11,806 reviews

Overall

8.0

Entertainment

7.0

Food

7.1

Crew

8.5

Boarding

8.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
Southwest
8.0
Very good
4,267 reviews
Alaska Airlines
8.0
Very good
11,806 reviews

Overall

8.0

Entertainment

7.0

Food

7.1

Crew

8.5

Boarding

8.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
Delta
7.9
Good
8,128 reviews
Alaska Airlines
8.0
Very good
11,806 reviews

Overall

8.0

Entertainment

7.0

Food

7.1

Crew

8.5

Boarding

8.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
United Airlines
7.4
Good
9,215 reviews
Alaska Airlines
8.0
Very good
11,806 reviews

Overall

8.0

Entertainment

7.0

Food

7.1

Crew

8.5

Boarding

8.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading
American Airlines
7.2
Good
11,205 reviews
Alaska Airlines
8.0
Very good
11,806 reviews

Overall

8.0

Entertainment

7.0

Food

7.1

Crew

8.5

Boarding

8.1

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,Jan 2026

STS - LAX

Enjoyed staff assistance from ticking thru tsa , boarding and in the plane Couldn’t pick a seat except upgrading

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.

  • How long is the flight from Illinois to Idaho?

    There are many flights that can get you from Illinois to Idaho in 5h 52m. Fly via United Airlines, Delta, or Alaska Airlines to get the fastest option. Illinois and Idaho are separated by a distance of 1378 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Illinois to Idaho one-way?

    One-way options have recently been found by users for as low as $87 on Delta. Other airlines that offer cheap prices include Southwest from $87 and American Airlines from $104 one-way.

  • Can I find deals for flights from Illinois to Idaho that include hotel bookings?

    Yes. In addition to deals on Illinois to Idaho flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to Idaho?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Idaho.

  • Can I find deals for business class flights from Illinois to Idaho?

    Yes. Cheapflights offers flight deals from Illinois to Idaho by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to Idaho?

    Currently, July is the cheapest month in which you can book a flight from Illinois to Idaho (average of $149). Flying from Illinois to Idaho in December is currently the most expensive (average of $288). 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.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Illinois to Idaho

See prices for flight routes from nearby airports that may be better suited for you.
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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 January 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$174Average$325FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$214Average$461FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$237Average$439FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$254Average$339FlexibilityNo cancel feeOn-time63%

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