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St. Louis

$85+ 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 2/22. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — STL
Jan 17 — Jan 241
Sat 1/17
Sat 1/24
1 adult, Economy
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Cheap 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 December 18, 2025.

This Southwest deal was found by Cheapflights users on 12/16. 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.
Wed 12/3111:45 amBOI - STL
1 stop5h 45mSouthwest
Sat 1/37:30 pmSTL - BOI
1 stop7h 10mSouthwest
Deal found 12/16$401
This American Airlines deal was found by Cheapflights users on 12/16. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:07 amGEG - STL
1 stop8h 16mAmerican Airlines
Sun 1/44:53 pmSTL - GEG
1 stop6h 35mAmerican Airlines
Deal found 12/16$421
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/2412:35 pmJAC - STL
1 stop8h 08mUnited Airlines
Wed 12/316:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$424
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/257:00 amJAC - STL
2 stops11h 18mUnited Airlines
Wed 12/316:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$430
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/267:00 amJAC - STL
2 stops11h 22mUnited Airlines
Wed 12/316:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$434
This Delta deal was found by Cheapflights users on 12/17. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/2412:50 pmJAC - STL
1 stop7h 44mDelta
Thu 12/257:20 amSTL - JAC
1 stop5h 35mDelta
Deal found 12/17$449
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/2412:35 pmJAC - STL
1 stop5h 43mUnited Airlines
Tue 12/306:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$474
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/211:00 pmJAC - STL
1 stop7h 55mUnited Airlines
Wed 12/316:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$479
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/257:00 amJAC - STL
2 stops11h 18mUnited Airlines
Tue 12/306:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$480
This United Airlines deal was found by Cheapflights users on 12/17. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/267:00 amJAC - STL
2 stops11h 22mUnited Airlines
Tue 12/306:00 amSTL - JAC
1 stop7h 04mUnited Airlines
Deal found 12/17$484
This Delta deal was found by Cheapflights users on 12/17. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/227:00 amJAC - STL
1 stop5h 23mDelta
Thu 12/257:20 amSTL - JAC
1 stop5h 35mDelta
Deal found 12/17$504
This United Airlines deal was found by Cheapflights users on 12/16. 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.
Wed 12/315:05 amGEG - STL
2 stops10h 49mUnited Airlines
Sun 1/45:02 pmSTL - GEG
1 stop7h 28mUnited Airlines
Deal found 12/16$516

Find 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 December 18, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$256
(Delta)

One-way from

$85
(Kiwi.com)

Popular in

January

Cheapest in

September

Average price

$443
Provider with most accurate pricing for Boise Air Term. Gowen Fld-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Boise Air Term. Gowen Fld-Lambert-St Louis flights.
Search Deals
From Idaho to Lambert-St Louis
Search Deals
One-way flight from Idaho to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 23% potential increase in price ($136 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 8% potential price decrease ($36 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

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 December 18, 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

Wed 1/14

10:39 am-9:35 pm

2 stops9h 56m

Lambert-St Louis

Tue 1/20

6:10 am-6:28 pm

2 stops13h 18m

$256

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Wed 1/14

5:55 pm-1:54 pm

1 stop18h 59m

Lambert-St Louis

Tue 1/20

2:50 pm-9:05 pm

1 stop7h 15m

$275

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Wed 1/14

2:37 pm-8:58 pm

1 stop5h 21m

Lambert-St Louis

Tue 1/20

11:20 am-9:52 pm

2 stops11h 32m

$281

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Mon 2/9

10:39 am-9:38 pm

2 stops9h 59m

Lambert-St Louis

Wed 2/11

6:40 am-6:28 pm

2 stops12h 48m

$296

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Fri 1/16

11:25 am-11:25 pm

2 stops10h 00m

Lambert-St Louis

Fri 1/23

3:31 pm-11:59 pm

2 stops10h 28m

$298

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Mon 2/9

1:55 pm-1:54 pm

1 stop22h 59m

Lambert-St Louis

Wed 2/11

2:50 pm-11:01 pm

1 stop9h 11m

$310

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Tue 1/20

5:45 am-1:54 pm

1 stop6h 09m

Lambert-St Louis

Mon 2/2

2:50 pm-11:38 am

2 stops22h 48m

$314

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Mon 2/2

6:23 am-1:54 pm

1 stop6h 31m

Lambert-St Louis

Tue 2/3

2:50 pm-9:05 pm

1 stop7h 15m

$317

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Tue 1/6

1:42 pm-11:59 pm

1 stop8h 17m

Lambert-St Louis

Thu 2/19

7:00 am-11:59 pm

1 stop18h 59m

$317

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Mon 1/12

1:58 pm-10:59 pm

1 stop8h 01m

Lambert-St Louis

Wed 1/14

7:15 am-1:08 pm

1 stop6h 53m

$318

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/16

Showing 1-10 of 49 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 $710). 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 December 18, 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.

How much does it cost to fly round-trip from Idaho to St. Louis?

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 Delta, Alaska Airlines, 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 Delta, which is currently one of the cheapest options available, starting at $82. United Airlines flights start at $148 while deals on Southwest start at $170 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 Spokane - Lambert-St Louis, Jackson Hole - Lambert-St Louis or Boise Air Term. Gowen Fld - 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 $710). 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
Swansea
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Idaho to St. Louis

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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 December 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$179Average$343FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$226Average$373FlexibilityNo cancel feeOn-time71%
Alaska AirlinesCheapest$278Average$488FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$281Average$449FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$286Average$607FlexibilityNo cancel feeOn-time69%

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