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St. Louis

$325+ Cheap flights from Idaho Falls to St. Louis (IDA - STL)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/6. Fares are subject to change and may not be available on all flights or dates of travel.
IDA — STL
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
1 adult, Economy
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Cheap flight deals from Idaho Falls to St. Louis

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

This United Airlines deal was found by Cheapflights users on 1/26. 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 3/62:35 pm
IDA
-
STL
1 stop7h 59m
United Airlines
Sat 3/147:41 am
STL
-
IDA
2 stops8h 59m
United Airlines
Deal found 1/26$325
This United Airlines deal was found by Cheapflights users on 1/24. 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 1/282:40 pm
IDA
-
STL
1 stop5h 18m
United Airlines
Sat 1/318:45 am
STL
-
IDA
1 stop5h 45m
United Airlines
Deal found 1/24$409
This Alaska Airlines deal was found by Cheapflights users on 1/26. 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 2/106:58 pm
IDA
-
STL
1 stop17h 56m
Alaska Airlines
Sat 2/142:47 pm
STL
-
IDA
1 stop9h 49m
Alaska Airlines
Deal found 1/26$430
This United Airlines deal was found by Cheapflights users on 1/26. 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 2/102:40 pm
IDA
-
STL
1 stop5h 18m
United Airlines
Sat 2/1411:25 am
STL
-
IDA
2 stops10h 33m
United Airlines
Deal found 1/26$434
This Alaska Airlines deal was found by Cheapflights users on 1/26. 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.
Mon 2/168:00 am
IDA
-
STL
1 stop28h 51m
Alaska Airlines
Mon 2/232:47 pm
STL
-
IDA
1 stop26h 56m
Alaska Airlines
Deal found 1/26$560

Find flight deals from Idaho Falls to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Idaho Falls (IDA) to St. Louis (STL). 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

FlightHub
3 stars

Round-trip from

$456
(Alaska Airlines)

Popular in

January

Cheapest in

August

Average price

$647
Provider with most accurate pricing for Idaho Falls Fanning Field-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Idaho Falls Fanning Field-Lambert-St Louis flights.
Search Deals
From Idaho Falls Fanning Field to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 8% potential increase in price ($48 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($12 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 Idaho Falls 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 January 26, 2026.
Use the filters below to find and compare flights from Idaho Falls to St. Louis that are best for you.

Fly from

Idaho Falls

Fly to

St. Louis

Route

Depart

Return

Price

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 3/6

2:35 pm-11:34 pm

1 stop7h 59m

Lambert-St Louis

Sat 3/14

7:41 am-3:40 pm

2 stops8h 59m

$325

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 2/10

6:58 pm-1:54 pm

1 stop17h 56m

Lambert-St Louis

Sat 2/14

2:47 pm-11:36 pm

1 stop9h 49m

$430

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 2/10

2:40 pm-8:58 pm

1 stop5h 18m

Lambert-St Louis

Sat 2/14

11:25 am-8:58 pm

2 stops10h 33m

$434

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 2/16

8:00 am-1:51 pm

1 stop28h 51m

Lambert-St Louis

Mon 2/23

2:47 pm-4:43 pm

1 stop26h 56m

$560

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sun 5/3

4:06 pm-3:50 pm

1 stop22h 44m

Lambert-St Louis

Sun 5/10

7:00 am-10:40 pm

1 stop16h 40m

$600

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sun 5/3

2:31 pm-8:43 pm

1 stop5h 12m

Lambert-St Louis

Sun 5/10

8:46 am-1:25 pm

1 stop5h 39m

$649

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/26

Compare providers for flights from Idaho Falls to St. Louis

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 Idaho Falls to St. Louis in January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust 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 Idaho Falls-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Idaho Falls-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Idaho Falls-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Idaho Falls-St. Louis 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 Idaho Falls-St. Louis 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 Idaho Falls to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Idaho Falls 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 Falls to St. Louis

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

Currently, July is the cheapest month in which you can book a flight from Idaho Falls to St. Louis (average of $223). Flying from Idaho Falls to St. Louis in June is currently the most expensive (average of $472). 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 Idaho Falls to St. Louis?

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated January 26, 2026.
Read reviews from past customers who have flown United Airlines and American Airlines from Idaho Falls to St. Louis. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,199 reviews

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
United Airlines
7.4
Good
9,199 reviews
United Airlines
7.4
Good
9,199 reviews

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
American Airlines
7.2
Good
11,189 reviews
United Airlines
7.4
Good
9,199 reviews

Crew

8.1

Boarding

7.7

Food

6.6

Entertainment

7.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family

Related info for your journey

Find useful and relevant information for your journey from Idaho Falls to St. Louis. 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 Idaho Falls to St. Louis?

    A quick flight from Idaho Falls to St. Louis can take about 5h 18m. Alaska Airlines provides one of the quickest options available for as low as $434. The distance from Idaho Falls to St. Louis is about 1171 mi. This flight may include one or multiple stops.

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

    Cheapflights users have booked flights from Idaho Falls to St. Louis round-trip from $326. Another airline that can offer you cheap pricing is United Airlines. Users have found that American Airlines is 37% cheaper than the other options available to this destination.

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

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

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

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

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

    Currently, July is the cheapest month in which you can book a flight from Idaho Falls to St. Louis (average of $223). Flying from Idaho Falls to St. Louis in June is currently the most expensive (average of $472). 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
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
Chesterfield
Alton
Farmington
Festus

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Top 2 airlines flying from Idaho Falls to St. Louis

Discover the top 2 airlines that operate flights from Idaho Falls 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 January 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$326Average$384FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$387Average$510FlexibilityNo cancel feeOn-time69%

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