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Idaho

$102+ 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 1/21. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
Feb 10 — Feb 171
Tue 2/10
Tue 2/17
1 adult, Economy
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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 January 11, 2026.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$130
(Kiwi.com)

One-way from

$102
(Booking.com)

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.
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Provider most trusted by Cheapflights users for Lambert-St Louis-Boise Air Term. Gowen Fld flights.
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From Lambert-St Louis to Idaho
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One-way flight from Lambert-St Louis to Idaho
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Highest demand for flights based on searches. 4% potential increase in price ($19 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in January 2026
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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 January 11, 2026.

This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/212:51 pmSTL - BOI
1 stop21h 20mFrontier
Fri 2/2711:56 amBOI - STL
1 stop25h 00mFrontier
Deal found 1/9$130
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/212:51 pmSTL - BOI
1 stop21h 20mFrontier
Thu 2/2612:38 pmBOI - STL
1 stop23h 31mFrontier
Deal found 1/9$135
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/184:51 pmSTL - BOI
1 stop20h 00mFrontier
Fri 2/2711:56 amBOI - STL
1 stop25h 00mFrontier
Deal found 1/9$170
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/184:51 pmSTL - BOI
1 stop20h 00mFrontier
Sun 2/2211:56 amBOI - STL
1 stop24h 13mFrontier
Deal found 1/9$176
This Kiwi.com deal was found by Cheapflights users on 1/10. 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.
Sun 2/812:03 pmSTL - BOI
1 stop24h 09mFrontier
Fri 2/1311:56 amBOI - STL
2 stops28h 50mFrontier
Deal found 1/10$220
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 3/258:12 pmSTL - BOI
1 stop16h 00mFrontier
Sun 3/2912:07 pmBOI - STL
1 stop20h 42mFrontier
Deal found 1/9$224
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/212:51 pmSTL - BOI
1 stop21h 20mMultiple Airlines
Thu 2/262:48 pmBOI - STL
2 stops29h 38mMultiple Airlines
Deal found 1/9$235
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/1910:11 pmSTL - BOI
2 stops14h 00mFrontier
Fri 2/2711:56 amBOI - STL
1 stop25h 00mFrontier
Deal found 1/9$236
This Kiwi.com deal was found by Cheapflights users on 1/9. 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 2/1910:11 pmSTL - BOI
2 stops14h 00mFrontier
Thu 2/2612:38 pmBOI - STL
1 stop23h 31mFrontier
Deal found 1/9$242
This United Airlines deal was found by Cheapflights users on 1/9. 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 1/248:45 amSTL - JAC
1 stop5h 36mUnited Airlines
Wed 1/282:40 pmJAC - STL
1 stop5h 18mUnited Airlines
Deal found 1/9$249
This Delta deal was found by Cheapflights users on 1/10. 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 2/142:22 pmSTL - JAC
1 stop5h 42mDelta
Fri 2/205:15 pmJAC - STL
1 stop6h 10mDelta
Deal found 1/10$257
This Delta deal was found by Cheapflights users on 1/10. 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 2/33:31 pmSTL - GEG
2 stops10h 28mDelta
Sat 2/71:20 pmGEG - STL
2 stops8h 05mDelta
Deal found 1/10$276

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 11, 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

Thu 2/19

6:40 pm-9:50 am

2 stops16h 10m

Boise Air Term. Gowen Fld

Wed 2/25

7:30 am-11:23 pm

2 stops14h 53m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Fri 2/20

6:40 pm-9:50 am

2 stops16h 10m

Boise Air Term. Gowen Fld

Tue 2/24

8:50 am-11:23 pm

2 stops13h 33m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Fri 2/20

6:40 pm-9:50 am

2 stops16h 10m

Boise Air Term. Gowen Fld

Wed 2/25

10:41 am-12:25 am

2 stops12h 44m

$256

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Tue 2/24

7:00 am-8:15 pm

2 stops14h 15m

Boise Air Term. Gowen Fld

Sat 2/28

5:50 am-9:38 pm

2 stops14h 48m

$256

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Sat 2/14

2:22 pm-7:04 pm

1 stop5h 42m

Jackson Hole

Fri 2/20

5:15 pm-12:25 am

1 stop6h 10m

$257

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Tue 2/3

3:31 pm-11:59 pm

2 stops10h 28m

Spokane

Sat 2/7

1:20 pm-11:25 pm

2 stops8h 05m

$276

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 2/21

3:40 pm-8:55 pm

1 stop6h 15m

Boise Air Term. Gowen Fld

Sat 2/28

5:50 am-9:38 pm

2 stops14h 48m

$276

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Fri 2/6

3:31 pm-11:59 pm

2 stops9h 28m

Boise Air Term. Gowen Fld

Thu 2/12

1:51 pm-11:23 pm

2 stops8h 32m

$276

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Mon 2/23

6:40 pm-9:50 am

2 stops16h 10m

Boise Air Term. Gowen Fld

Sat 2/28

12:59 pm-9:38 pm

1 stop7h 39m

$276

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Fri 2/20

6:40 pm-9:50 am

2 stops16h 10m

Boise Air Term. Gowen Fld

Sat 2/28

5:20 am-2:54 pm

1 stop8h 34m

$276

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/9

Showing 1-10 of 58 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 11, 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
4,254 reviews

Entertainment

7.5

Overall

8.0

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

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

Entertainment

7.5

Overall

8.0

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

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
8,034 reviews
Southwest
8.0
Very good
4,254 reviews

Entertainment

7.5

Overall

8.0

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

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
9,143 reviews
Southwest
8.0
Very good
4,254 reviews

Entertainment

7.5

Overall

8.0

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

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
11,106 reviews
Southwest
8.0
Very good
4,254 reviews

Entertainment

7.5

Overall

8.0

Food

7.0

Comfort

8.0

Crew

8.6

Boarding

8.1

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 $329, Delta can have you in Idaho from St. Louis in 7h 18m. Airlines will cover a distance of 1107 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 11, 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$186Average$366FlexibilityNo cancel feeOn-time71%
DeltaCheapest$192Average$387FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$296Average$430FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$338Average$514FlexibilityNo cancel feeOn-time69%

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