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Idaho

$103+ 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 12/3. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
Dec 26 — Jan 21
Fri 12/26
Fri 1/2
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 26, 2025.

This Kiwi.com deal was found by Cheapflights users on 11/25. 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 12/107:43 pmSTL - BOI
1 stop17h 06mMultiple Airlines
Thu 12/119:17 pmBOI - STL
1 stop13h 05mMultiple Airlines
Deal found 11/25$275
This Delta deal was found by Cheapflights users on 11/24. 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 12/102:20 pmSTL - JAC
1 stop8h 09mDelta
Sun 12/145:50 pmJAC - STL
1 stop5h 58mDelta
Deal found 11/24$281
This Kiwi.com deal was found by Cheapflights users on 11/26. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/107:43 pmSTL - GEG
1 stop17h 30mMultiple Airlines
Sun 12/149:13 pmGEG - STL
2 stops47h 20mMultiple Airlines
Deal found 11/26$374
This Alaska Airlines deal was found by Cheapflights users on 11/24. 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 12/157:00 amSTL - BOI
1 stop16h 56mAlaska Airlines
Sun 1/46:08 amBOI - STL
1 stop16h 51mAlaska Airlines
Deal found 11/24$375
This Southwest deal was found by Cheapflights users on 11/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/168:50 amSTL - BOI
1 stop9h 00mSouthwest
Sat 12/204:20 pmBOI - STL
1 stop8h 00mSouthwest
Deal found 11/24$382
This Delta deal was found by Cheapflights users on 11/25. 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 12/168:05 pmSTL - BOI
1 stop5h 37mDelta
Tue 12/301:55 pmBOI - STL
1 stop8h 47mDelta
Deal found 11/25$397
This Delta deal was found by Cheapflights users on 11/24. 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 12/116:15 amSTL - GEG
1 stop7h 55mDelta
Sat 1/102:00 pmGEG - STL
1 stop7h 25mDelta
Deal found 11/24$407
This Delta deal was found by Cheapflights users on 11/24. 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.
Mon 12/152:20 pmSTL - BOI
2 stops10h 44mDelta
Sun 1/411:47 pmBOI - STL
1 stop8h 05mDelta
Deal found 11/24$407
This Southwest deal was found by Cheapflights users on 11/25. 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 12/207:25 pmSTL - BOI
1 stop6h 20mSouthwest
Wed 12/242:40 pmBOI - STL
1 stop5h 20mSouthwest
Deal found 11/25$409
This United Airlines deal was found by Cheapflights users on 11/24. 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 12/1611:25 amSTL - BOI
2 stops9h 18mUnited Airlines
Sat 12/202:40 pmBOI - STL
1 stop6h 42mUnited Airlines
Deal found 11/24$410
This Kiwi.com deal was found by Cheapflights users on 11/26. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/37:43 pmSTL - GEG
1 stop17h 30mMultiple Airlines
Sun 12/79:13 pmGEG - STL
2 stops47h 20mMultiple Airlines
Deal found 11/26$417
This Kiwi.com deal was found by Cheapflights users on 11/24. 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 12/2210:10 pmSTL - GEG
1 stop14h 19mMultiple Airlines
Sun 12/2812:02 pmGEG - STL
2 stops31h 23mMultiple Airlines
Deal found 11/24$420

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 26, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$198
(Kiwi.com)

One-way from

$103
(Trip.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
One-way flight from Lambert-St Louis to Idaho
Search Deals
Highest demand for flights based on searches. 6% potential increase in price ($29 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 26, 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. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 2/14

7:43 pm-11:59 am

1 stop17h 16m

Boise Air Term. Gowen Fld

Thu 2/19

12:54 pm-10:02 am

1 stop20h 08m

$219

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Sat 1/24

6:40 am-3:00 pm

2 stops10h 20m

Spokane

Wed 1/28

6:05 am-9:38 pm

2 stops13h 33m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 2/14

7:00 am-6:22 pm

2 stops12h 22m

Boise Air Term. Gowen Fld

Thu 2/19

1:51 pm-11:23 pm

2 stops8h 32m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 2/14

7:00 am-6:22 pm

2 stops12h 22m

Boise Air Term. Gowen Fld

Fri 2/20

10:41 am-12:25 am

2 stops12h 44m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 2/14

7:00 am-6:22 pm

2 stops12h 22m

Boise Air Term. Gowen Fld

Wed 2/18

5:40 am-12:25 am

2 stops17h 45m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 2/14

7:00 am-6:22 pm

2 stops12h 22m

Boise Air Term. Gowen Fld

Tue 2/17

1:51 pm-12:25 am

2 stops9h 34m

$256

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Tue 1/20

2:38 pm-7:06 pm

1 stop5h 28m

Jackson Hole

Sat 1/24

12:58 pm-9:38 pm

1 stop7h 40m

$257

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Wed 1/21

2:38 pm-7:06 pm

1 stop5h 28m

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

Fri 1/23

2:38 pm-7:06 pm

1 stop5h 28m

Jackson Hole

Thu 1/29

12:58 pm-11:25 pm

2 stops9h 27m

$262

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/23

Showing 1-10 of 47 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 26, 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.

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 26, 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
4,254 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Crew

8.6

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
4,254 reviews
Southwest
8.0
Very good
4,254 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Crew

8.6

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
7,999 reviews
Southwest
8.0
Very good
4,254 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Crew

8.6

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
9,046 reviews
Southwest
8.0
Very good
4,254 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Crew

8.6

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
11,038 reviews
Southwest
8.0
Very good
4,254 reviews

Overall

8.0

Boarding

8.1

Food

7.0

Entertainment

7.5

Comfort

8.0

Crew

8.6

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 $267, Frontier can have you in Idaho from St. Louis in 6h 45m. Airlines will cover a distance of 1488 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 Frontier ($103), Delta ($148), and American Airlines ($181).

  • 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 - Boise Air Term. Gowen Fld.

  • 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 26, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$186Average$366FlexibilityNo cancel feeOn-time71%
DeltaCheapest$192Average$387FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$286Average$526FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$292Average$414FlexibilityNo cancel feeOn-time63%

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