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Idaho

$172+ Cheap flights from St. Louis (STL) to Idaho

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/3. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
Dec 20 — Dec 271
Sat 12/20
Sat 12/27
1 adult, Economy
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Find 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 November 20, 2025.

This Kiwi.com deal was found by Cheapflights users on 11/17. 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 12/37:43 pmSTL - BOI
1 stop17h 06mFrontier
Sun 12/712:44 pmBOI - STL
2 stops20h 08mFrontier
Deal found 11/17$172
This Delta deal was found by Cheapflights users on 11/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/116:00 amSTL - BOI
2 stops11h 02mDelta
Mon 12/151:54 pmBOI - STL
2 stops9h 54mDelta
Deal found 11/18$256
This Delta deal was found by Cheapflights users on 11/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/32:20 pmSTL - JAC
1 stop8h 09mDelta
Sun 12/75:50 pmJAC - STL
1 stop5h 58mDelta
Deal found 11/18$281
This Delta deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/42:20 pmSTL - JAC
1 stop8h 09mDelta
Mon 12/812:55 pmJAC - STL
2 stops9h 47mDelta
Deal found 11/19$315
This Kiwi.com deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/1910:10 pmSTL - BOI
2 stops14h 49mMultiple Airlines
Mon 12/2210:41 pmBOI - STL
1 stop21h 44mMultiple Airlines
Deal found 11/19$342
This Alaska Airlines deal was found by Cheapflights users on 11/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/117:00 amSTL - BOI
1 stop6h 45mAlaska Airlines
Mon 12/158:55 amBOI - STL
1 stop14h 04mAlaska Airlines
Deal found 11/18$345
This Delta deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/182:20 pmSTL - JAC
1 stop8h 09mDelta
Wed 12/2412:50 pmJAC - STL
1 stop7h 44mDelta
Deal found 11/19$354
This American Airlines deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/147:38 amSTL - GEG
1 stop8h 11mAmerican Airlines
Sat 12/2011:59 pmGEG - STL
1 stop8h 51mAmerican Airlines
Deal found 11/19$388
This Kiwi.com deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/41:16 pmSTL - BOI
1 stop27h 28mMultiple Airlines
Mon 12/810:41 pmBOI - STL
2 stops34h 33mMultiple Airlines
Deal found 11/19$396
This Alaska Airlines deal was found by Cheapflights users on 11/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/57:00 amSTL - BOI
1 stop9h 26mAlaska Airlines
Tue 12/96:03 amBOI - STL
1 stop7h 24mAlaska Airlines
Deal found 11/20$421
This Kiwi.com deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/227:43 pmSTL - GEG
2 stops16h 46mMultiple Airlines
Sun 12/2812:02 pmGEG - STL
1 stop20h 00mMultiple Airlines
Deal found 11/19$444
This United Airlines deal was found by Cheapflights users on 11/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/49:00 amSTL - GEG
1 stop8h 16mUnited Airlines
Mon 12/85:25 amGEG - STL
1 stop5h 14mUnited Airlines
Deal found 11/19$447

Cheap 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 November 20, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$172
(Kiwi.com)

Popular in

February

Cheapest in

April

Average price

$411
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
Highest demand for flights based on searches. 5% potential increase in price ($23 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
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 November 20, 2025.
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. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Sat 1/24

6:40 am-8:53 pm

2 stops16h 13m

Spokane

Wed 1/28

9:20 am-9:38 pm

2 stops10h 18m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Thu 12/11

6:00 am-4:02 pm

2 stops11h 02m

Boise Air Term. Gowen Fld

Mon 12/15

1:54 pm-12:48 am

2 stops9h 54m

$256

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Tue 1/20

6:40 am-11:58 am

1 stop6h 18m

Jackson Hole

Sat 1/24

12:58 pm-9:38 pm

1 stop7h 40m

$257

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Thu 1/8

7:10 am-1:30 pm

1 stop7h 20m

Jackson Hole

Tue 1/13

12:58 pm-9:35 pm

1 stop7h 37m

$257

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Thu 12/4

2:20 pm-9:29 pm

1 stop8h 09m

Jackson Hole

Mon 12/8

12:55 pm-7:10 pm

1 stop5h 15m

$281

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Thu 1/8

7:00 am-4:17 pm

2 stops10h 17m

Boise Air Term. Gowen Fld

Fri 1/9

7:25 am-9:35 pm

2 stops13h 10m

$296

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Mon 1/5

6:00 am-12:46 pm

1 stop7h 46m

Boise Air Term. Gowen Fld

Fri 1/9

7:25 am-9:35 pm

2 stops13h 10m

$336

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Mon 1/5

6:41 am-1:05 pm

1 stop7h 24m

Boise Air Term. Gowen Fld

Sat 1/10

2:52 pm-11:59 pm

1 stop8h 07m

$337

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Thu 12/11

7:00 am-12:45 pm

1 stop6h 45m

Boise Air Term. Gowen Fld

Mon 12/15

8:55 am-11:59 pm

1 stop14h 04m

$345

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 3/3

7:00 am-4:23 pm

1 stop10h 23m

Idaho Falls Fanning Field

Wed 3/4

9:00 am-1:51 pm

1 stop27h 51m

$353

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/19

Showing 1-10 of 42 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 $300). 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 STL to ID?

Find hourly flight availability from St. Louis 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 November 20, 2025.

It’s optimal to fly from St. Louis to Idaho in the evening. By choosing this option you can save up to 15% on the cost of your flight, compared to a flight in the morning.

How much does it cost to fly round-trip from St. Louis 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 November 20, 2025.
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
4,251 reviews

Overall

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Southwest
8.0
Very good
4,251 reviews
Southwest
8.0
Very good
4,251 reviews

Overall

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Delta
7.9
Good
8,002 reviews
Southwest
8.0
Very good
4,251 reviews

Overall

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
United Airlines
7.4
Good
9,028 reviews
Southwest
8.0
Very good
4,251 reviews

Overall

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
American Airlines
7.2
Good
11,047 reviews
Southwest
8.0
Very good
4,251 reviews

Overall

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines

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 $408, Delta can have you in Idaho from St. Louis in 5h 17m. Airlines will cover a distance of 1141 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 Delta ($199), Southwest ($224), and Alaska Airlines ($235).

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

    The most popular route from St. Louis to Idaho is Lambert-St Louis - Jackson Hole. You may also consider Lambert-St Louis - Spokane or Lambert-St Louis - Idaho Falls Fanning Field.

  • 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 $300). 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 November 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$186Average$366FlexibilityNo cancel feeOn-time71%
DeltaCheapest$192Average$386FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$292Average$437FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$300Average$520FlexibilityNo cancel feeOn-time69%

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