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$310+ 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 7/7. Fares are subject to change and may not be available on all flights or dates of travel.
IDA — STL
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
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 June 12, 2025.

Round-trip from

$361
(American Airlines)

One-way from

$310
(Delta)

Popular in

January

Cheapest in

February

Average price

$561
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. 4% potential increase in price ($25 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($31 potential savings vs. average RT price).
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Average for round-trip flights in June 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 June 12, 2025.

This American Airlines deal was found by Cheapflights users on 6/11. 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.
Sat 11/151:50 pmIDA - STL
1 stop7h 39mAmerican Airlines
Thu 11/205:26 amSTL - IDA
1 stop7h 53mAmerican Airlines
Deal found 6/11$361
This Delta deal was found by Cheapflights users on 6/9. 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.
Fri 8/16:52 pmIDA - STL
1 stop4h 46mDelta
Sat 8/95:00 pmSTL - IDA
1 stop6h 29mDelta
Deal found 6/9$385
This United Airlines deal was found by Cheapflights users on 6/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/45:00 amIDA - STL
1 stop6h 46mUnited Airlines
Sun 7/65:15 amSTL - IDA
1 stop5h 29mUnited Airlines
Deal found 6/10$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 June 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

Sat 11/15

1:50 pm-10:29 pm

1 stop7h 39m

Lambert-St Louis

Thu 11/20

5:26 am-12:19 pm

1 stop7h 53m

$361

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 8/1

6:52 pm-12:38 am

1 stop4h 46m

Lambert-St Louis

Sat 8/9

5:00 pm-10:29 pm

1 stop6h 29m

$385

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 7/4

5:00 am-12:46 pm

1 stop6h 46m

Lambert-St Louis

Sun 7/6

5:15 am-9:44 am

1 stop5h 29m

$431

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 7/7

6:52 pm-12:38 am

1 stop4h 46m

$310

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 7/7

5:04 pm-10:29 am

3 stops40h 25m

$320

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 7/7

6:03 pm-2:37 pm

2 stops19h 34m

$394

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sun 7/6

6:51 am-8:31 pm

1 stop12h 40m

$504

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

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 June 12, 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.

Rainfall in St. Louis by month

Plan your trip to St. Louis by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in St. Louis ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Louis when rainfall is around 2.2 in.

Temperature in St. Louis by month

Plan your trip to St. Louis by taking into account the average temperature totals by month.

If weather is an important factor for your trip to St. Louis, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

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 June 12, 2025.
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Crew

8.5

Comfort

7.9

Overall

8.0

Food

7.3

Entertainment

7.9

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
7,950 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Crew

8.5

Comfort

7.9

Overall

8.0

Food

7.3

Entertainment

7.9

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
8,790 reviews
Delta
8.0
Very good
7,950 reviews

Boarding

8.2

Crew

8.5

Comfort

7.9

Overall

8.0

Food

7.3

Entertainment

7.9

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
7,950 reviews

Boarding

8.2

Crew

8.5

Comfort

7.9

Overall

8.0

Food

7.3

Entertainment

7.9

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.

  • 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 $361. Other airlines that can offer you cheap pricing are Delta, from $385, and United Airlines, from $431. Users have found that American Airlines is 36% cheaper than the other options available to this destination.

  • What are the cheapest airlines to fly from Idaho Falls to St. Louis one-way?

    The cheapest airlines for a one-way flight from Idaho Falls to St. Louis are Delta ($310), United Airlines ($394), and American Airlines ($504).

  • 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 Idaho Falls?

Book flights to Idaho Falls if you plan to visit one of these locations
O'Fallon
Maryland Heights
Fairview Heights
Collinsville
Eureka
St. Peters
Glencoe
Festus
Alton
Farmington

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