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Idaho

$119+ Cheap flights from St. Louis (STL) 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 3/31. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
Feb 28 — Mar 71
Sat 2/28
Sat 3/7
1 adult, Economy
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Cheap flight deals from St. Louis to Idaho

Cheapest flights from St. Louis to Idaho
Explore the most affordable flight options available from St. Louis to Idaho. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 29, 2026.

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 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 Delta 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/247:00 am
STL
-
JAC
1 stop6h 07m
Delta
Tue 3/35:15 pm
JAC
-
STL
1 stop6h 10m
Delta
Deal found 1/27$257
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.
Sat 3/148:12 pm
STL
-
BOI
1 stop16h 08m
Frontier
Sun 3/2212:15 pm
BOI
-
STL
1 stop20h 34m
Frontier
Deal found 1/27$265
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.
Thu 2/262:47 pm
STL
-
JAC
2 stops22h 37m
Alaska Airlines
Thu 3/511:48 am
JAC
-
STL
2 stops25h 03m
Alaska Airlines
Deal found 1/28$267
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.
Tue 3/37:00 am
STL
-
GEG
1 stop9h 36m
Alaska Airlines
Wed 3/45:40 am
GEG
-
STL
1 stop6h 11m
Alaska Airlines
Deal found 1/28$277
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.
Fri 5/16:45 pm
STL
-
IDA
1 stop4h 55m
Delta
Tue 5/126:50 pm
IDA
-
STL
1 stop4h 46m
Delta
Deal found 1/28$279
This United 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/3111:15 am
STL
-
BOI
2 stops11h 07m
United Airlines
Sat 4/42:37 pm
BOI
-
STL
1 stop5h 17m
United Airlines
Deal found 1/28$285
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 3/317:00 am
STL
-
BOI
1 stop9h 29m
Alaska Airlines
Thu 4/28:20 am
BOI
-
STL
1 stop14h 39m
Alaska Airlines
Deal found 1/27$290
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
Multiple Airlines
Thu 3/195:20 pm
BOI
-
STL
2 stops16h 59m
Multiple Airlines
Deal found 1/27$291

Find flight deals from St. Louis to Idaho

Keep the following information in mind while searching for St. Louis 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

$197
(Kiwi.com)

One-way from

$119
(American Airlines)

Popular in

February

Cheapest in

November

Average price

$359
Provider with most accurate pricing for Lambert-St Louis-Boise Air Term. Gowen Fld flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Boise Air Term. Gowen Fld flights.
Search Deals
From Lambert-St Louis to Idaho
Search Deals
One-way flight from Lambert-St Louis to Idaho
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($19 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis 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 St. Louis to Idaho that are best for you.

Fly from

St. Louis

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

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

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

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Tue 3/3

7:00 am-2:36 pm

1 stop9h 36m

Spokane

Wed 3/4

5:40 am-1:51 pm

1 stop6h 11m

$277

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 5/1

6:45 pm-10:40 pm

1 stop4h 55m

Idaho Falls Fanning Field

Tue 5/12

6:50 pm-12:36 am

1 stop4h 46m

$279

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Tue 3/31

7:00 am-3:29 pm

1 stop9h 29m

Boise Air Term. Gowen Fld

Thu 4/2

8:20 am-11:59 pm

1 stop14h 39m

$290

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sun 4/5

6:12 pm-10:11 pm

1 stop4h 59m

Boise Air Term. Gowen Fld

Sat 4/11

5:30 am-11:48 am

1 stop5h 18m

$290

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Mon 3/9

4:13 pm-9:12 pm

1 stop6h 59m

Spokane

Wed 3/11

6:00 am-3:28 pm

1 stop7h 28m

$294

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Sat 7/4

1:30 pm-5:52 pm

1 stop5h 22m

Jackson Hole

Thu 7/9

7:50 am-5:53 pm

1 stop9h 03m

$299

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 St. Louis to Idaho

Have a flexible travel schedule? Discover the best time to fly to Idaho from St. Louis 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 St. Louis to Idaho

What is the cheapest month to book a flight from St. Louis to Idaho?

Currently, September is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $186). Flying from St. Louis to Idaho in January is currently the most expensive (average of $359). 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.

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.
Peruse reviews from past customers who have flown with Southwest, Delta, and United Airlines from St. Louis to Idaho to help guide your decision. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,267 reviews

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Southwest
8.0
Very good
4,267 reviews
Southwest
8.0
Very good
4,267 reviews

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Delta
7.9
Good
8,128 reviews
Southwest
8.0
Very good
4,267 reviews

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
United Airlines
7.4
Good
9,215 reviews
Southwest
8.0
Very good
4,267 reviews

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
American Airlines
7.2
Good
11,205 reviews
Southwest
8.0
Very good
4,267 reviews

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Overall

8.0

Food

7.0

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Idaho. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from St. Louis to Idaho?

    For a flight from St. Louis to Idaho, you will be flying from Lambert-St Louis. Lambert-St Louis (STL) is just 12.7 mi from the center of the city.

  • How long is the flight from St. Louis to Idaho?

    For as low as $237, United Airlines can have you in Idaho from St. Louis in 5h 52m. Airlines will cover a distance of 1378 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from St. Louis to Idaho one-way?

    The cheapest airlines for a one-way flight from St. Louis to Idaho are Southwest ($82), Delta ($139), and United Airlines ($156).

  • What are the most popular routes from St. Louis to Idaho?

    The most popular route from St. Louis to Idaho is Lambert-St Louis - Boise Air Term. Gowen Fld. You may also consider Lambert-St Louis - Jackson Hole or Lambert-St Louis - Spokane.

  • Can I find deals for flights from St. Louis to Idaho that include hotel bookings?

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

  • How can I find direct flights from St. Louis to Idaho?

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

  • Can I find deals for business class flights from St. Louis to Idaho?

    Yes. Cheapflights offers flight deals from St. Louis 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 St. Louis to Idaho?

    Currently, September is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $186). Flying from St. Louis to Idaho in January is currently the most expensive (average of $359). 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

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Alternative routes for St. Louis 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 St. Louis to Idaho

Discover the top 4 airlines that operate flights from St. Louis 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$163Average$386FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$186Average$366FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$296Average$421FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$338Average$526FlexibilityNo cancel feeOn-time69%

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