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Idaho

$139+ 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 10/15. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
oct. 17 — oct. 241
vie. 10/17
vie. 10/24
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 septiembre 17, 2025.

Round-trip from

$164
(Booking.com)

One-way from

$139
(Kiwi.com)

Popular in

December

Cheapest in

April

Average price

$382
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. 6% potential increase in price ($29 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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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 septiembre 17, 2025.

This Booking.com deal was found by Cheapflights users on 9/16. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/17:55 pmSTL - BOI
1 stop16h 42mFrontier
dom. 10/512:22 pmBOI - STL
1 stop19h 44mFrontier
Deal found 9/16$164
This Kiwi.com deal was found by Cheapflights users on 9/15. 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.
mié. 10/157:52 pmSTL - BOI
1 stop16h 51mFrontier
dom. 10/1912:28 pmBOI - STL
1 stop19h 39mFrontier
Deal found 9/15$244
This Delta deal was found by Cheapflights users on 9/16. 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.
mié. 10/87:30 pmSTL - BOI
1 stop5h 29mDelta
mar. 10/1411:12 amBOI - STL
1 stop6h 28mDelta
Deal found 9/16$277
This United Airlines deal was found by Cheapflights users on 9/16. 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.
mié. 10/85:15 amSTL - BOI
2 stops9h 28mUnited Airlines
mié. 10/222:39 pmBOI - STL
1 stop5h 07mUnited Airlines
Deal found 9/16$282
This Hawaiian Airlines deal was found by Cheapflights users on 9/16. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/57:00 amSTL - BOI
1 stop9h 12mHawaiian Airlines
lun. 11/102:20 pmBOI - STL
1 stop8h 39mHawaiian Airlines
Deal found 9/16$286
This Southwest deal was found by Cheapflights users on 9/16. 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.
mié. 10/85:40 amSTL - BOI
1 stop7h 10mSouthwest
mié. 10/223:15 pmBOI - STL
1 stop7h 55mSouthwest
Deal found 9/16$287
This Alaska Airlines deal was found by Cheapflights users on 9/15. 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.
mié. 10/156:33 amSTL - GEG
1 stop6h 25mAlaska Airlines
mié. 10/221:31 pmGEG - STL
1 stop8h 32mAlaska Airlines
Deal found 9/15$290
This Delta deal was found by Cheapflights users on 9/15. 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.
lun. 10/207:30 pmSTL - GEG
1 stop6h 13mDelta
lun. 10/274:50 pmGEG - STL
1 stop5h 34mDelta
Deal found 9/15$291
This Southwest deal was found by Cheapflights users on 9/16. 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.
mié. 10/83:00 pmSTL - BOI
1 stop8h 10mSouthwest
mar. 10/142:35 pmBOI - STL
2 stops8h 35mSouthwest
Deal found 9/16$292
This Southwest deal was found by Cheapflights users on 9/16. 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.
lun. 10/274:40 pmSTL - GEG
2 stops9h 40mSouthwest
mié. 10/2912:50 pmGEG - STL
1 stop8h 20mSouthwest
Deal found 9/16$296
This Hawaiian Airlines deal was found by Cheapflights users on 9/15. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 11/67:00 amSTL - BOI
1 stop9h 12mHawaiian Airlines
lun. 11/106:28 amBOI - STL
1 stop7h 50mHawaiian Airlines
Deal found 9/15$296
This United Airlines deal was found by Cheapflights users on 9/16. 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.
sáb. 10/115:35 pmSTL - BOI
1 stop7h 09mUnited Airlines
sáb. 10/2510:40 amBOI - STL
1 stop4h 52mUnited Airlines
Deal found 9/16$297

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 septiembre 17, 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

mié. 10/1

7:55 pm-11:37 am

1 stop16h 42m

Boise Air Term. Gowen Fld

dom. 10/5

12:22 pm-9:06 am

1 stop19h 44m

$164

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mié. 10/15

7:52 pm-11:43 am

1 stop16h 51m

Boise Air Term. Gowen Fld

dom. 10/19

12:28 pm-9:07 am

1 stop19h 39m

$244

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mar. 1/27

6:45 am-6:25 pm

2 stops12h 40m

Boise Air Term. Gowen Fld

sáb. 1/31

2:00 pm-12:37 am

2 stops9h 37m

$268

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mié. 1/28

6:45 am-8:13 pm

2 stops14h 28m

Boise Air Term. Gowen Fld

sáb. 1/31

2:00 pm-12:37 am

2 stops9h 37m

$268

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mar. 1/27

2:55 pm-10:20 pm

1 stop8h 25m

Boise Air Term. Gowen Fld

sáb. 1/31

5:30 am-1:52 pm

1 stop7h 22m

$269

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mié. 10/8

5:15 am-9:53 am

1 stop5h 38m

Boise Air Term. Gowen Fld

mié. 10/22

2:39 pm-8:46 pm

1 stop5h 07m

$277

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mié. 10/8

7:30 pm-11:59 pm

1 stop5h 29m

Boise Air Term. Gowen Fld

mar. 10/14

11:12 am-6:40 pm

1 stop6h 28m

$277

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mié. 11/5

7:00 am-3:12 pm

1 stop9h 12m

Boise Air Term. Gowen Fld

lun. 11/10

2:20 pm-11:59 pm

1 stop8h 39m

$286

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

lun. 11/17

7:00 am-12:35 pm

1 stop6h 35m

Boise Air Term. Gowen Fld

mié. 11/19

1:25 pm-10:59 pm

1 stop8h 34m

$287

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

mié. 1/28

2:55 pm-10:20 pm

1 stop8h 25m

Boise Air Term. Gowen Fld

sáb. 1/31

5:30 am-1:52 pm

1 stop7h 22m

$287

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/17

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, October is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $314). Flying from St. Louis to Idaho in June is currently the most expensive (average of $398). 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 septiembre 17, 2025.

When flying from St. Louis to Idaho, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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 septiembre 17, 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
4,242 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Boarding

8.1

Crew

8.6

Overall

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
4,242 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Boarding

8.1

Crew

8.6

Overall

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
8.0
Very good
7,961 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Boarding

8.1

Crew

8.6

Overall

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
8,926 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Boarding

8.1

Crew

8.6

Overall

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
10,000 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Entertainment

7.5

Food

7.0

Boarding

8.1

Crew

8.6

Overall

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 $269, Frontier can have you in Idaho from St. Louis in 8h 25m. 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 Hawaiian Airlines ($141), Frontier ($142), and American Airlines ($186).

  • 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, October is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $314). Flying from St. Louis to Idaho in June is currently the most expensive (average of $398). 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 septiembre 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$186Average$366FlexibilityNo cancel feeOn-time71%
DeltaCheapest$192Average$388FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$286Average$548FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$292Average$435FlexibilityNo cancel feeOn-time63%

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