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$186+ 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 11/11. Fares are subject to change and may not be available on all flights or dates of travel.
IDA — STL
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheap 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 September 11, 2025.

Round-trip from

$370
(Hawaiian Airlines)

One-way from

$186
(Delta)

Popular in

January

Cheapest in

February

Average price

$430
From Idaho Falls Fanning Field to Lambert-St Louis
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One-way flight from Idaho Falls Fanning Field to Lambert-St Louis
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Highest demand for flights based on searches. 8% potential increase in price ($50 potential increase over avg. RT price).
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Cheapest flight prices on average. 6% potential price decrease ($31 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find 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 September 11, 2025.

This Hawaiian Airlines deal was found by Cheapflights users on 9/9. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/74:15 pmIDA - STL
1 stop6h 48mHawaiian Airlines
Tue 10/146:33 amSTL - IDA
1 stop10h 05mHawaiian Airlines
Deal found 9/9$370
This Alaska Airlines deal was found by Cheapflights users on 9/9. 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 10/74:15 pmIDA - STL
1 stop6h 48mAlaska Airlines
Tue 10/146:33 amSTL - IDA
1 stop10h 05mAlaska Airlines
Deal found 9/9$371
This United Airlines deal was found by Cheapflights users on 9/9. 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 10/85:56 pmIDA - STL
1 stop5h 02mUnited Airlines
Wed 10/155:00 amSTL - IDA
2 stops9h 33mUnited Airlines
Deal found 9/9$376
This Hawaiian Airlines deal was found by Cheapflights users on 9/11. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/154:15 pmIDA - STL
1 stop6h 48mHawaiian Airlines
Sat 10/186:33 amSTL - IDA
1 stop10h 05mHawaiian Airlines
Deal found 9/11$379
This Delta deal was found by Cheapflights users on 9/9. 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 11/106:57 pmIDA - STL
2 stops12h 19mDelta
Mon 11/249:04 amSTL - IDA
2 stops10h 13mDelta
Deal found 9/9$381
This United Airlines deal was found by Cheapflights users on 9/9. 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 11/144:15 pmIDA - STL
1 stop4h 39mUnited Airlines
Sun 11/169:00 amSTL - IDA
1 stop5h 35mUnited Airlines
Deal found 9/9$388
This United Airlines deal was found by Cheapflights users on 9/9. 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.
Mon 12/292:30 pmIDA - STL
1 stop6h 52mUnited Airlines
Sat 1/179:57 amSTL - IDA
2 stops12h 17mUnited Airlines
Deal found 9/9$393
This American Airlines deal was found by Cheapflights users on 9/9. 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.
Tue 11/111:58 pmIDA - STL
1 stop8h 00mAmerican Airlines
Sun 11/167:00 amSTL - IDA
1 stop7h 27mAmerican Airlines
Deal found 9/9$401
This Hawaiian Airlines deal was found by Cheapflights users on 9/9. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/96:05 amIDA - STL
1 stop8h 13mHawaiian Airlines
Fri 11/147:00 amSTL - IDA
1 stop9h 13mHawaiian Airlines
Deal found 9/9$404
This United Airlines deal was found by Cheapflights users on 9/9. 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 10/72:35 pmIDA - STL
1 stop5h 11mUnited Airlines
Tue 10/1412:25 pmSTL - IDA
2 stops9h 27mUnited Airlines
Deal found 9/9$424
This United Airlines deal was found by Cheapflights users on 9/9. 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 9/244:15 pmIDA - STL
1 stop6h 38mUnited Airlines
Sun 9/285:15 amSTL - IDA
1 stop5h 33mUnited Airlines
Deal found 9/9$431

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 September 11, 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

Tue 10/7

4:15 pm-12:03 am

1 stop6h 48m

Lambert-St Louis

Tue 10/14

6:33 am-3:38 pm

1 stop10h 05m

$371

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 11/10

4:15 pm-9:54 pm

1 stop4h 39m

Lambert-St Louis

Mon 11/24

9:00 am-3:16 pm

1 stop7h 16m

$371

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Wed 10/8

5:56 pm-11:58 pm

1 stop5h 02m

Lambert-St Louis

Wed 10/15

5:15 am-9:48 am

1 stop5h 33m

$371

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 11/10

6:57 pm-12:46 am

1 stop4h 49m

Lambert-St Louis

Mon 11/24

9:04 am-6:17 pm

2 stops10h 13m

$376

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Wed 10/15

4:15 pm-12:03 am

1 stop6h 48m

Lambert-St Louis

Sat 10/18

6:33 am-3:38 pm

1 stop10h 05m

$379

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 11/14

4:15 pm-9:54 pm

1 stop4h 39m

Lambert-St Louis

Sun 11/16

9:00 am-1:35 pm

1 stop5h 35m

$388

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 11/11

1:58 pm-10:58 pm

1 stop8h 00m

Lambert-St Louis

Sun 11/16

7:00 am-1:27 pm

1 stop7h 27m

$401

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sun 11/9

6:05 am-3:18 pm

1 stop8h 13m

Lambert-St Louis

Fri 11/14

7:00 am-3:13 pm

1 stop9h 13m

$404

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 10/7

2:35 pm-8:46 pm

1 stop5h 11m

Lambert-St Louis

Tue 10/14

12:25 pm-8:52 pm

2 stops9h 27m

$424

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 9/26

5:56 pm-11:58 pm

1 stop5h 02m

Lambert-St Louis

Tue 9/30

9:00 am-1:33 pm

1 stop5h 33m

$431

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/9

Showing 1-10 of 12 results
1
2

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 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 September 11, 2025.

Unlike at noon, when flights are generally more expensive, you can save up to 23% on flights from Idaho Falls to St. Louis by exploring options for tickets in the afternoon.

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 September 11, 2025.
Read reviews from past customers who have flown Delta, 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.
Delta
8.0
Very good
7,960 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Delta
8.0
Very good
7,960 reviews
Delta
8.0
Very good
7,960 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
United Airlines
7.4
Good
8,937 reviews
Delta
8.0
Very good
7,960 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,960 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Crew

8.5

Overall

8.0

Food

7.3

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

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 4h 39m. Alaska Airlines provides one of the quickest options available for as low as $371. 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 $284. Other airlines that can offer you cheap pricing are American Airlines, from $324, and United Airlines, from $387. Users have found that Delta is 47% 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, August is the cheapest month in which you can book a flight from Idaho Falls to St. Louis (average of $311). Flying from Idaho Falls to St. Louis in March is currently the most expensive (average of $356). 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
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Top 3 airlines flying from Idaho Falls to St. Louis

Discover the top 3 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 September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$284Average$510FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$324Average$384FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$387Average$510FlexibilityNo cancel feeOn-time69%

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