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Idaho Falls

$200+ 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 7/5. Fares are subject to change and may not be available on all flights or dates of travel.
STL — IDA
Apr 14 — Apr 211
Tue 4/14
Tue 4/21
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 March 15, 2026.

This United Airlines deal was found by Cheapflights users on 3/12. 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 8/295:10 am
STL
-
IDA
1 stop5h 43m
United Airlines
Tue 9/15:53 pm
IDA
-
STL
1 stop4h 57m
United Airlines
Deal found 3/12$319
This Delta deal was found by Cheapflights users on 3/11. 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.
Fri 12/252:15 pm
STL
-
IDA
1 stop4h 59m
Delta
Sat 1/26:45 pm
IDA
-
STL
1 stop4h 51m
Delta
Deal found 3/11$369
This United Airlines deal was found by Cheapflights users on 3/12. 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 5/58:46 am
STL
-
IDA
1 stop5h 39m
United Airlines
Sat 5/92:31 pm
IDA
-
STL
1 stop5h 12m
United Airlines
Deal found 3/12$399
This United Airlines deal was found by Cheapflights users on 3/12. 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 3/229:00 am
STL
-
IDA
1 stop5h 30m
United Airlines
Sun 3/292:30 pm
IDA
-
STL
1 stop5h 24m
United Airlines
Deal found 3/12$407
This Alaska Airlines deal was found by Cheapflights users on 3/15. 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.
Thu 10/86:41 am
STL
-
IDA
1 stop9h 48m
Alaska Airlines
Mon 10/124:03 pm
IDA
-
STL
1 stop6h 56m
Alaska Airlines
Deal found 3/15$414
This United Airlines deal was found by Cheapflights users on 3/11. 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 4/148:54 am
STL
-
IDA
1 stop5h 38m
United Airlines
Fri 4/172:30 pm
IDA
-
STL
1 stop5h 24m
United Airlines
Deal found 3/11$434
This Alaska Airlines deal was found by Cheapflights users on 3/12. 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.
Wed 4/157:00 am
STL
-
IDA
1 stop16h 52m
Alaska Airlines
Mon 4/204:59 pm
IDA
-
STL
1 stop20h 52m
Alaska Airlines
Deal found 3/12$451
This Delta deal was found by Cheapflights users on 3/10. 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 4/76:12 pm
STL
-
IDA
1 stop5h 04m
Delta
Tue 4/146:58 pm
IDA
-
STL
2 stops12h 32m
Delta
Deal found 3/10$452

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 March 15, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$319
(United Airlines)

One-way from

$200
(United Airlines)

Popular in

November

Cheapest in

August

Average price

$409
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. 13% potential increase in price ($78 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($22 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 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 March 15, 2026.
Use the filters below to find and compare flights from St. Louis to Idaho Falls that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 5/5

8:46 am-1:25 pm

1 stop5h 39m

Idaho Falls Fanning Field

Sat 5/9

2:31 pm-8:43 pm

1 stop5h 12m

$399

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 4/24

4:46 pm-3:29 pm

1 stop23h 43m

Idaho Falls Fanning Field

Fri 5/1

4:06 pm-11:59 pm

1 stop6h 53m

$459

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 4/7

6:12 pm-10:16 pm

1 stop5h 04m

Idaho Falls Fanning Field

Tue 4/14

5:47 am-1:23 pm

1 stop6h 36m

$499
Cheapest one-way
Quickest one-way

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 7/5

5:10 am-9:50 am

1 stop5h 40m

$200

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 7/5

6:40 pm-4:00 pm

1 stop22h 20m

$275

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 7/5

7:00 am-1:24 pm

1 stop7h 24m

$316

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/11

Sorted by cheapest first

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 March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars

*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 FlightHub the most. FlightHub 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, July is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $239). Flying from St. Louis to Idaho Falls in January is currently the most expensive (average of $411). 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 March 15, 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
8,293 reviews

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Crew

8.5

Overall

7.9

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
8,293 reviews
Delta
7.9
Good
8,293 reviews

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Crew

8.5

Overall

7.9

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
9,427 reviews
Delta
7.9
Good
8,293 reviews

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Crew

8.5

Overall

7.9

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 United Airlines fly from St. Louis to Idaho Falls in about 5h 39m. The time it takes to get you to your destination can typically vary by up to . Airlines will cover a distance of 1171 mi.

  • 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 66% 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, July is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $239). Flying from St. Louis to Idaho Falls in January is currently the most expensive (average of $411). 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?

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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 March 15, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$163Average$384FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$338Average$464FlexibilityNo cancel feeOn-time69%

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