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$386+ Cheap flights from Idaho Falls to St. Louis (IDA - STL)

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 12/17. Fares are subject to change and may not be available on all flights or dates of travel.
IDA — STL
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
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 December 12, 2025.

This Delta 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/176:00 amIDA - STL
1 stop6h 30mDelta
Wed 12/247:20 amSTL - IDA
1 stop6h 07mDelta
Deal found 12/11$666
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.
Wed 12/171:58 pmIDA - STL
1 stop7h 49mAmerican Airlines
Sun 1/42:43 pmSTL - IDA
1 stop8h 38mAmerican Airlines
Deal found 12/11$891
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.
Wed 12/177:00 amIDA - STL
1 stop4h 39mUnited Airlines
Sun 1/46:30 amSTL - IDA
2 stops9h 52mUnited Airlines
Deal found 12/11$990

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 December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Popular in

January

Cheapest in

February

Average price

$645
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
Highest demand for flights based on searches. 10% potential increase in price ($62 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($28 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
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 December 12, 2025.
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

Wed 12/17

6:00 am-1:30 pm

1 stop6h 30m

$386

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Wed 12/17

1:26 pm-10:33 pm

3 stops56h 07m

$580

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Wed 12/17

1:58 pm-8:35 am

2 stops17h 37m

$661

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

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 December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice 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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Idaho Falls-St. Louis flight deals on Cheapflights vs. eDreams >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 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 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 January is currently the most expensive (average of $850). 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.

What is the cheapest time of day to fly from IDA to STL?

Find hourly flight availability from Idaho Falls to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 12, 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 43% on flights from Idaho Falls to St. Louis by exploring options for tickets at noon.

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 December 12, 2025.
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
9,095 reviews

Overall

7.4

Boarding

7.7

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Sunderesh,Dec 2025

AUS - EWR

Smooth flight from Austin to Newark. The crew was friendly.
United Airlines
7.4
Good
9,095 reviews
United Airlines
7.4
Good
9,095 reviews

Overall

7.4

Boarding

7.7

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Sunderesh,Dec 2025

AUS - EWR

Smooth flight from Austin to Newark. The crew was friendly.
American Airlines
7.2
Good
11,050 reviews
United Airlines
7.4
Good
9,095 reviews

Overall

7.4

Boarding

7.7

Crew

8.1

Entertainment

7.1

Food

6.6

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Sunderesh,Dec 2025

AUS - EWR

Smooth flight from Austin to Newark. The crew was friendly.

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.

  • 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 $324. Another airline that can offer you cheap pricing is United Airlines. Users have found that American Airlines is 40% 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 January is currently the most expensive (average of $850). 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
Fairview Heights
Maryland Heights
Collinsville
Swansea
Eureka
Glencoe
St. Peters
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 December 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$324Average$384FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$387Average$510FlexibilityNo cancel feeOn-time69%

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