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St. Louis

$76+ Cheap flights from Idaho to St. Louis (STL)

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 12/11. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — STL
Nov 29 — Dec 61
Sat 11/29
Sat 12/6
1 adult, Economy
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Cheap flight deals from Idaho to St. Louis

Keep the following information in mind while searching for Idaho to St. Louis flight deals. Data was last updated October 30, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$253
(Kiwi.com)

One-way from

$76
(Booking.com)

Popular in

January

Cheapest in

September

Average price

$401
Provider with most accurate pricing for Boise Air Term. Gowen Fld-Lambert-St Louis flight deals.
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Provider most trusted by Cheapflights users for Boise Air Term. Gowen Fld-Lambert-St Louis flights.
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From Idaho to Lambert-St Louis
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One-way flight from Idaho to Lambert-St Louis
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Highest demand for flights based on searches. 19% potential increase in price ($105 potential increase over avg. RT price).
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Cheapest flight prices on average. 9% potential price decrease ($37 potential savings vs. average RT price).
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Average for round-trip flights in October 2025
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Find flight deals from Idaho to St. Louis

Cheapest flights from Idaho to St. Louis
Explore the most affordable flight options available from Idaho to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 30, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/30. 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 11/271:52 pmIDA - STL
1 stop24h 16mMultiple Airlines
Wed 12/37:43 pmSTL - IDA
2 stops43h 53mMultiple Airlines
Deal found 10/30$270
This Kiwi.com deal was found by Cheapflights users on 10/30. 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 11/271:52 pmIDA - STL
1 stop24h 16mMultiple Airlines
Thu 12/41:16 pmSTL - IDA
1 stop25h 00mMultiple Airlines
Deal found 10/30$273
This Kiwi.com deal was found by Cheapflights users on 10/29. 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 12/312:19 pmIDA - STL
1 stop22h 53mMultiple Airlines
Wed 12/107:43 pmSTL - IDA
2 stops43h 53mMultiple Airlines
Deal found 10/29$281
This Kiwi.com deal was found by Cheapflights users on 10/28. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/1612:03 pmGEG - STL
1 stop19h 04mMultiple Airlines
Wed 11/197:45 pmSTL - GEG
2 stops22h 22mMultiple Airlines
Deal found 10/28$302
This Delta deal was found by Cheapflights users on 10/29. 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.
Sun 12/711:44 amBOI - STL
2 stops10h 45mDelta
Tue 12/99:00 amSTL - BOI
1 stop6h 18mDelta
Deal found 10/29$315
This Delta deal was found by Cheapflights users on 10/30. 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 11/276:00 amBOI - STL
1 stop8h 05mDelta
Thu 12/42:20 pmSTL - BOI
2 stops8h 56mDelta
Deal found 10/30$330
This Kiwi.com deal was found by Cheapflights users on 10/30. 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 11/710:56 pmIDA - STL
2 stops33h 11mMultiple Airlines
Thu 12/41:16 pmSTL - IDA
1 stop25h 00mMultiple Airlines
Deal found 10/30$335
This Kiwi.com deal was found by Cheapflights users on 10/30. 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 11/2610:51 pmIDA - STL
1 stop21h 18mMultiple Airlines
Wed 12/37:43 pmSTL - IDA
2 stops43h 53mMultiple Airlines
Deal found 10/30$340
This Kiwi.com deal was found by Cheapflights users on 10/30. 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 11/2610:51 pmIDA - STL
1 stop21h 18mMultiple Airlines
Thu 12/41:16 pmSTL - IDA
1 stop25h 00mMultiple Airlines
Deal found 10/30$342
This Alaska Airlines deal was found by Cheapflights users on 10/29. 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.
Sun 12/76:03 amBOI - STL
1 stop7h 24mAlaska Airlines
Tue 12/97:00 amSTL - BOI
1 stop9h 26mAlaska Airlines
Deal found 10/29$349
This United Airlines deal was found by Cheapflights users on 10/28. 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 11/112:43 pmSUN - STL
1 stop6h 11mUnited Airlines
Fri 11/149:00 amSTL - SUN
1 stop5h 40mUnited Airlines
Deal found 10/28$351
This Delta deal was found by Cheapflights users on 10/30. 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 11/201:50 pmBOI - STL
2 stops9h 56mDelta
Sun 11/236:00 amSTL - BOI
2 stops11h 05mDelta
Deal found 10/30$355

Cheapflights Fare Finder

 
Customize your flight search to find flights from Idaho to St. Louis 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 October 30, 2025.
Use the filters below to find and compare flights from Idaho to St. Louis that are best for you.

Fly from

Idaho

Fly to

St. Louis

Route

Depart

Return

Price

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Fri 1/9

12:54 pm-10:02 am

1 stop20h 08m

Lambert-St Louis

Tue 1/13

5:06 pm-11:54 am

2 stops43h 48m

$253

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Sat 1/10

1:45 pm-11:25 pm

2 stops8h 40m

Lambert-St Louis

Tue 1/13

11:23 am-9:58 pm

2 stops11h 35m

$274

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Fri 1/9

8:50 am-9:35 pm

2 stops11h 45m

Lambert-St Louis

Tue 1/13

11:23 am-9:58 pm

2 stops11h 35m

$284

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Sat 1/10

2:37 pm-8:58 pm

1 stop5h 21m

Lambert-St Louis

Tue 1/13

9:57 am-7:45 pm

2 stops10h 48m

$302

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Sun 11/16

12:03 pm-9:07 am

1 stop19h 04m

Lambert-St Louis

Wed 11/19

7:45 pm-4:07 pm

2 stops22h 22m

$302

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 11/27

1:52 pm-3:08 pm

1 stop24h 16m

Lambert-St Louis

Thu 12/4

1:16 pm-7:26 pm

2 stops31h 10m

$302

JacksonSt. Louis

JAC - STL

JACSTL

Jackson Hole

Thu 4/16

5:30 pm-12:36 am

1 stop6h 06m

Lambert-St Louis

Mon 4/20

2:15 pm-6:57 pm

1 stop5h 42m

$309

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Sun 12/7

1:54 pm-12:48 am

2 stops9h 54m

Lambert-St Louis

Tue 12/9

6:00 am-4:02 pm

2 stops11h 02m

$324

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Thu 11/27

6:00 am-3:05 pm

1 stop8h 05m

Lambert-St Louis

Thu 12/4

2:20 pm-10:16 pm

2 stops8h 56m

$330

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Mon 1/5

1:00 pm-9:35 pm

1 stop7h 35m

Lambert-St Louis

Fri 1/9

6:00 am-12:51 pm

1 stop7h 51m

$341

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/27

Showing 1-10 of 60 results
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Best time to book a flight from Idaho to St. Louis

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

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

Currently, April is the cheapest month in which you can book a flight from Idaho to St. Louis (average of $113). Flying from Idaho to St. Louis in January is currently the most expensive (average of $555). 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 ID to STL?

Find hourly flight availability from Idaho to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 30, 2025.

It’s optimal to fly from Idaho to St. Louis in the evening. By choosing this option you can save up to 21% on the cost of your flight, compared to a flight in the morning.

Related info for your journey

Find useful and relevant information for your journey from Idaho to St. Louis. 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 into for flights to St. Louis from Idaho?

    Located just 12.7 mi from the city center, Lambert-St Louis (STL) is the airport most travelers will use when flying to St. Louis from Idaho.

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

    There are many flights that can get you from Idaho to St. Louis in 5h 21m. Fly via Frontier, Delta, or United Airlines to get the fastest option. Idaho and St. Louis are separated by a distance of 1378 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $109. Delta flights start at $138 while deals on American Airlines start at $164 one-way.

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

    When deciding which route to take from Idaho to St. Louis consider Boise Air Term. Gowen Fld - Lambert-St Louis, Spokane - Lambert-St Louis or Idaho Falls Fanning Field - Lambert-St Louis as they are the most popular.

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

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

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

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

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

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

    Currently, April is the cheapest month in which you can book a flight from Idaho to St. Louis (average of $113). Flying from Idaho to St. Louis in January is currently the most expensive (average of $555). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Top 5 airlines flying from Idaho to St. Louis

Discover the top 5 airlines that operate flights from Idaho to St. Louis. 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 October 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$184Average$341FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$226Average$373FlexibilityNo cancel feeOn-time71%
Alaska AirlinesCheapest$278Average$488FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$286Average$453FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$286Average$608FlexibilityNo cancel feeOn-time69%

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