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Idaho Falls

$281+ 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 12/18. Fares are subject to change and may not be available on all flights or dates of travel.
STL — IDA
ene. 11 — ene. 181
dom. 1/11
dom. 1/18
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 diciembre 12, 2025.

This American Airlines deal was found by Cheapflights users on 12/11. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 12/262:43 pmSTL - IDA
1 stop8h 38mAmerican Airlines
mar. 12/301:16 pmIDA - STL
1 stop8h 40mAmerican Airlines
Deal found 12/11$746
This United Airlines deal was found by Cheapflights users on 12/11. 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.
vie. 12/266:30 amSTL - IDA
2 stops17h 29mUnited Airlines
mar. 12/305:00 amIDA - STL
2 stops10h 27mUnited Airlines
Deal found 12/11$868
This American Airlines deal was found by Cheapflights users on 12/10. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 12/122:37 pmSTL - IDA
1 stop8h 59mAmerican Airlines
mar. 12/167:00 amIDA - STL
2 stops15h 57mAmerican Airlines
Deal found 12/10$948

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 diciembre 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$371
(Alaska Airlines)

One-way from

$281
(American Airlines)

Popular in

November

Cheapest in

January

Average price

$455
Provider with most accurate pricing for Lambert-St Louis-Idaho Falls Fanning Field flight deals.
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Provider most trusted by Cheapflights users for Lambert-St Louis-Idaho Falls Fanning Field flights.
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From Lambert-St Louis to Idaho Falls Fanning Field
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One-way flight from Lambert-St Louis to Idaho Falls Fanning Field
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Highest demand for flights based on searches. 11% potential increase in price ($63 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease ($21 potential savings vs. average RT price).
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Average for round-trip flights in December 2025
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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 diciembre 12, 2025.
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

jue. 1/22

2:50 pm-10:59 pm

1 stop9h 09m

Idaho Falls Fanning Field

lun. 1/26

6:58 pm-1:54 pm

1 stop17h 56m

$371

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

jue. 1/22

8:05 am-3:31 pm

2 stops8h 26m

Idaho Falls Fanning Field

lun. 1/26

2:40 pm-8:58 pm

1 stop5h 18m

$376

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 3/9

3:25 pm-10:20 pm

2 stops7h 55m

Idaho Falls Fanning Field

vie. 3/13

6:59 pm-8:52 am

2 stops12h 53m

$381

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

mié. 2/4

2:50 pm-10:59 pm

1 stop9h 09m

Idaho Falls Fanning Field

sáb. 2/7

6:58 pm-1:54 pm

1 stop17h 56m

$397

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 4/20

2:15 pm-6:14 pm

1 stop4h 59m

Idaho Falls Fanning Field

vie. 4/24

6:50 pm-12:36 am

1 stop4h 46m

$405

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 3/9

7:00 am-4:43 pm

1 stop10h 43m

Idaho Falls Fanning Field

vie. 3/13

8:00 am-11:59 pm

1 stop14h 59m

$420

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

mié. 2/4

2:45 pm-9:14 pm

1 stop7h 29m

Idaho Falls Fanning Field

sáb. 2/7

6:30 am-1:16 pm

1 stop5h 46m

$468

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

jue. 12/18

7:00 am-12:46 pm

1 stop6h 46m

$281

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

jue. 12/18

2:45 pm-9:14 pm

1 stop7h 29m

$321

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/10

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 December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice 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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on St. Louis-Idaho Falls flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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, May is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $199). 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.

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

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 diciembre 12, 2025.
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
8,007 reviews

Food

7.3

Comfort

7.9

Crew

8.5

Boarding

8.1

Entertainment

7.9

Overall

7.9

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
8,007 reviews
Delta
7.9
Good
8,007 reviews

Food

7.3

Comfort

7.9

Crew

8.5

Boarding

8.1

Entertainment

7.9

Overall

7.9

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
9,095 reviews
Delta
7.9
Good
8,007 reviews

Food

7.3

Comfort

7.9

Crew

8.5

Boarding

8.1

Entertainment

7.9

Overall

7.9

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, United Airlines, and Delta fly from St. Louis to Idaho Falls in about 7h 55m. The time it takes to get you to your destination can typically vary by up to 1h 14m. 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 $192, 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 61% 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, May is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $199). 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 diciembre 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$192Average$384FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$400Average$578FlexibilityNo cancel feeOn-time69%

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