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Idaho Falls

$242+ 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 7/25. Fares are subject to change and may not be available on all flights or dates of travel.
STL — IDA
Aug 7 — Aug 141
Fri 8/7
Fri 8/14
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 July 8, 2026.

This Alaska Airlines deal was found by Cheapflights users on 7/6. 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 9/153:19 pm
STL
-
IDA
1 stop8h 37m
Alaska Airlines
Mon 9/213:57 pm
IDA
-
STL
1 stop24h 13m
Alaska Airlines
Deal found 7/6$344
This Delta deal was found by Cheapflights users on 7/6. 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 9/151:55 pm
STL
-
IDA
2 stops9h 27m
Delta
Mon 9/216:57 pm
IDA
-
STL
1 stop4h 47m
Delta
Deal found 7/6$349
This Delta deal was found by Cheapflights users on 7/7. 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 9/152:25 pm
STL
-
IDA
1 stop4h 52m
Delta
Sun 9/206:57 pm
IDA
-
STL
1 stop4h 47m
Delta
Deal found 7/7$369
This United Airlines deal was found by Cheapflights users on 7/5. 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 8/299:00 am
STL
-
IDA
1 stop5h 29m
United Airlines
Wed 9/22:25 pm
IDA
-
STL
1 stop5h 21m
United Airlines
Deal found 7/5$409
This United Airlines deal was found by Cheapflights users on 7/6. 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 9/69:00 am
STL
-
IDA
1 stop7h 23m
United Airlines
Sat 9/124:04 pm
IDA
-
STL
1 stop6h 36m
United Airlines
Deal found 7/6$422
This Delta deal was found by Cheapflights users on 7/7. 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 9/1412:00 pm
STL
-
IDA
2 stops11h 22m
Delta
Sun 9/206:57 pm
IDA
-
STL
1 stop4h 47m
Delta
Deal found 7/7$424
This United Airlines deal was found by Cheapflights users on 7/4. 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 7/254:45 pm
STL
-
IDA
1 stop5h 22m
United Airlines
Tue 7/282:30 pm
IDA
-
STL
1 stop5h 13m
United Airlines
Deal found 7/4$427

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 July 8, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$344
(Alaska Airlines)

One-way from

$242
(United Airlines)

Popular in

June

Cheapest in

August

Average price

$517
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 ($47 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($27 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 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 July 8, 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

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 9/15

11:21 am-6:17 pm

2 stops7h 56m

Idaho Falls Fanning Field

Sun 9/20

6:57 pm-12:44 am

1 stop4h 47m

$374

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 8/8

5:00 pm-10:32 pm

1 stop6h 32m

Idaho Falls Fanning Field

Sat 8/15

7:00 pm-8:10 am

2 stops12h 10m

$384

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 8/29

9:00 am-1:29 pm

1 stop5h 29m

Idaho Falls Fanning Field

Wed 9/2

2:25 pm-8:46 pm

1 stop5h 21m

$409
Quickest round-trip

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Mon 8/3

5:10 am-9:50 am

1 stop5h 40m

Idaho Falls Fanning Field

Sat 8/8

5:54 pm-11:47 pm

1 stop4h 53m

$490

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 9/6

6:00 am-3:23 pm

2 stops10h 23m

Idaho Falls Fanning Field

Sat 9/12

10:35 am-9:30 pm

2 stops9h 55m

$547
Cheapest one-way
Quickest one-way

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 7/25

6:00 am-11:45 am

1 stop6h 45m

$242

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 7/25

8:08 pm-3:00 pm

2 stops43h 52m

$369

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/6

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 July.
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

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 July 8, 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
7.8
Good
8,450 reviews

Boarding

8.1

Comfort

7.8

Overall

7.8

Crew

8.5

Food

7.2

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
Delta
7.8
Good
8,450 reviews
Delta
7.8
Good
8,450 reviews

Boarding

8.1

Comfort

7.8

Overall

7.8

Crew

8.5

Food

7.2

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional
United Airlines
7.4
Good
9,944 reviews
Delta
7.8
Good
8,450 reviews

Boarding

8.1

Comfort

7.8

Overall

7.8

Crew

8.5

Food

7.2

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2026

SEA - KOA

The snacks were not very good, not everyone was very friendly and professional

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 Delta and United Airlines fly from St. Louis to Idaho Falls in about 5h 29m. The time it takes to get you to your destination can typically vary by up to 2h 27m. 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 $367, 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 36% 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.

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 July 8, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$367Average$509FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$387Average$635FlexibilityNo cancel feeOn-time69%

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