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Idaho Falls

$185+ Cheap flights from St. Louis to Idaho Falls (STL - IDA)

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 2/26. Fares are subject to change and may not be available on all flights or dates of travel.
STL — IDA
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
1 adult, Economy
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Cheap flight deals from St. Louis to Idaho Falls

Cheapest flights from St. Louis to Idaho Falls
Explore the most affordable flight options available from St. Louis to Idaho Falls. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 26, 2026.

This Alaska Airlines deal was found by Cheapflights users on 1/25. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/247:00 am
STL
-
IDA
1 stop9h 29m
Alaska Airlines
Wed 4/294:06 pm
IDA
-
STL
1 stop6h 53m
Alaska Airlines
Deal found 1/25$324
This Alaska Airlines deal was found by Cheapflights users on 1/25. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/37:00 am
STL
-
IDA
1 stop10h 43m
Alaska Airlines
Wed 3/45:20 pm
IDA
-
STL
1 stop19h 31m
Alaska Airlines
Deal found 1/25$393
This Delta deal was found by Cheapflights users on 1/25. 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.
Thu 1/296:40 am
STL
-
IDA
1 stop6h 54m
Delta
Tue 2/35:25 am
IDA
-
STL
1 stop7h 23m
Delta
Deal found 1/25$409
This Delta deal was found by Cheapflights users on 1/25. 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 1/273:31 pm
STL
-
IDA
2 stops8h 26m
Delta
Wed 2/45:25 am
IDA
-
STL
1 stop7h 23m
Delta
Deal found 1/25$414
This United Airlines deal was found by Cheapflights users on 1/25. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 1/278:45 am
STL
-
IDA
1 stop7h 46m
United Airlines
Sat 1/316:30 am
IDA
-
STL
1 stop5h 46m
United Airlines
Deal found 1/25$419
This Delta deal was found by Cheapflights users on 1/25. 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 1/273:31 pm
STL
-
IDA
2 stops8h 26m
Delta
Tue 2/36:35 pm
IDA
-
STL
2 stops13h 18m
Delta
Deal found 1/25$420
This Travelocity deal was found by Cheapflights users on 1/25. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/177:56 pm
STL
-
IDA
1 stop20h 35m
Alaska Airlines
Sun 5/246:00 am
IDA
-
STL
1 stop8h 50m
Alaska Airlines
Deal found 1/25$449
This United Airlines deal was found by Cheapflights users on 1/25. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/39:55 am
STL
-
IDA
2 stops12h 03m
United Airlines
Wed 3/42:40 pm
IDA
-
STL
1 stop7h 41m
United Airlines
Deal found 1/25$456

Find flight deals from St. Louis to Idaho Falls

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Idaho Falls (IDA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated January 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

Expedia
3 stars

Round-trip from

$324
(Alaska Airlines)

One-way from

$185
(Alaska Airlines)

Popular in

November

Cheapest in

August

Average price

$589
Provider with most accurate pricing for Lambert-St Louis-Idaho Falls Fanning Field flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Idaho Falls Fanning Field flights.
Search Deals
From Lambert-St Louis to Idaho Falls Fanning Field
Search Deals
One-way flight from Lambert-St Louis to Idaho Falls Fanning Field
Search Deals
Highest demand for flights based on searches. 7% potential increase in price ($43 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($19 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Idaho Falls 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 26, 2026.
Use the filters below to find and compare flights from St. Louis to Idaho Falls that are best for you.

Fly from

St. Louis

Fly to

Idaho Falls

Route

Depart

Return

Price

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 3/3

7:00 am-11:36 pm

1 stop17h 36m

Idaho Falls Fanning Field

Wed 3/4

5:20 pm-11:59 pm

1 stop29h 39m

$393

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 3/3

9:55 am-8:58 pm

2 stops12h 03m

Idaho Falls Fanning Field

Wed 3/4

10:45 am-4:58 pm

1 stop5h 13m

$456

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 6/12

7:30 pm-3:40 pm

1 stop21h 10m

Idaho Falls Fanning Field

Fri 6/19

4:17 pm-5:13 pm

1 stop23h 56m

$485

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 3/27

7:00 am-10:52 pm

1 stop16h 52m

Idaho Falls Fanning Field

Sun 3/29

5:59 pm-3:20 pm

1 stop20h 21m

$486

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 4/24

8:54 am-1:24 pm

1 stop5h 30m

Idaho Falls Fanning Field

Wed 4/29

10:40 am-10:56 pm

2 stops11h 16m

$492

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 2/13

2:47 pm-11:36 pm

1 stop9h 49m

Idaho Falls Fanning Field

Sun 2/15

8:00 am-11:59 pm

1 stop14h 59m

$516

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Thu 2/26

2:47 pm-11:36 pm

1 stop9h 49m

$185

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 7/5

4:30 pm-9:08 pm

1 stop5h 38m

$349

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 7/5

6:20 pm-11:59 pm

2 stops30h 39m

$481

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/25

Compare providers for flights from St. Louis to Idaho Falls

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Idaho Falls in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on St. Louis-Idaho Falls flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Idaho Falls flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Idaho Falls flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on St. Louis-Idaho Falls flights, Cheapflights users trust Expedia the most. Expedia has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Idaho Falls flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from St. Louis to Idaho Falls

Have a flexible travel schedule? Discover the best time to fly to Idaho Falls 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 Falls

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

Currently, April is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $202). Flying from St. Louis to Idaho Falls in November is currently the most expensive (average of $401). 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 Falls

Get insights into the airlines that provide service to Idaho Falls. 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 Falls. Reviews last updated January 26, 2026.
Peruse reviews from past customers who have flown with Delta and United Airlines from St. Louis to Idaho Falls to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,111 reviews

Comfort

7.9

Boarding

8.1

Overall

7.9

Entertainment

7.8

Crew

8.5

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Delta
7.9
Good
8,111 reviews
Delta
7.9
Good
8,111 reviews

Comfort

7.9

Boarding

8.1

Overall

7.9

Entertainment

7.8

Crew

8.5

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
United Airlines
7.4
Good
9,199 reviews
Delta
7.9
Good
8,111 reviews

Comfort

7.9

Boarding

8.1

Overall

7.9

Entertainment

7.8

Crew

8.5

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Idaho Falls. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

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

    Airlines like Alaska Airlines and United Airlines fly from St. Louis to Idaho Falls in about 12h 03m. The time it takes to get you to your destination can typically vary by up to 5h 33m. Airlines will cover a distance of 1171 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from St. Louis to Idaho Falls round-trip?

    Delta, at $163, was found to be the cheapest airline from St. Louis to Idaho Falls. An alternate airline flying to your destination would be United Airlines. Delta is priced at 68% lower than the current average price of a flight leaving 3 months from now.

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

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

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

    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 Falls.

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

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

    Currently, April is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $202). Flying from St. Louis to Idaho Falls in November is currently the most expensive (average of $401). 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 Idaho Falls?

Book flights to Idaho Falls if you plan to visit one of these locations
Rexburg

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Top 2 airlines flying from St. Louis to Idaho Falls

Discover the top 2 airlines that operate flights from St. Louis to Idaho Falls. 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 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$163Average$384FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$355Average$576FlexibilityNo cancel feeOn-time69%

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