STL - IDA

$185 Find Cheap Flights from St. Louis to Idaho Falls - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Idaho Falls departing on 7/20. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$344
Typical prices: $324-$643
Delta
Mon 8/10Thu 8/13
STL - IDA • 1 stop
Cheapest one-way
$185
American Airlines
Mon 7/20
STL - IDA • 1 stop
Top airlines
Cheapest • from $384 (round-trip)
Best reviews • 7.8 score
Airline reviews
Airline reviews
+1
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Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between St. Louis and Idaho Falls. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $367 (round-trip)
Shortest trip • 5h 41m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 100% price drop
Most popular
Good to know
Good to know
+1
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Good to know
Good to know
+1
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We hope you love your trip to Idaho Falls!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from St. Louis to Idaho Falls (STL-IDA)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Idaho Falls that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from St. Louis to Idaho Falls

Mon, Aug 10 - Thu, Aug 13
Delta Logo
8:00 am - 2:35 pm
STL
-
IDA
7h 35m
1 stop
Delta Logo
7:00 pm - 12:41 am
IDA
-
STL
4h 41m
1 stop
$344Delta
Wed, Aug 19 - Sun, Aug 23
Delta Logo
2:32 pm - 6:20 pm
STL
-
IDA
4h 48m
1 stop
Delta Logo
7:00 pm - 12:41 am
IDA
-
STL
4h 41m
1 stop
$379Delta
Sat, Aug 8 - Sat, Aug 15
Delta Logo
5:00 pm - 10:32 pm
STL
-
IDA
6h 32m
1 stop
Delta Logo
7:00 pm - 8:10 am
IDA
-
STL
12h 10m
2 stops
$384Delta
Sat, Aug 29 - Wed, Sep 2
United Airlines Logo
9:00 am - 1:29 pm
STL
-
IDA
5h 29m
1 stop
United Airlines Logo
2:25 pm - 8:46 pm
IDA
-
STL
5h 21m
1 stop
$409United Airlines
Sat, Aug 29 - Wed, Sep 2
United Airlines Logo
8:30 am - 3:23 pm
STL
-
IDA
7h 53m
2 stops
United Airlines Logo
2:25 pm - 8:46 pm
IDA
-
STL
5h 21m
1 stop
$414United Airlines
Sat, Jul 25 - Tue, Jul 28
United Airlines Logo
4:45 pm - 9:07 pm
STL
-
IDA
5h 22m
1 stop
United Airlines Logo
2:30 pm - 8:43 pm
IDA
-
STL
5h 13m
1 stop
$427United Airlines
Sat, Jul 25 - Tue, Jul 28
United Airlines Logo
6:00 am - 11:45 am
STL
-
IDA
6h 45m
1 stop
United Airlines Logo
2:30 pm - 8:43 pm
IDA
-
STL
5h 13m
1 stop
$439United Airlines
Tue, Sep 15 - Mon, Sep 21
Alaska Airlines Logo
6:29 am - 3:20 pm
STL
-
IDA
9h 51m
1 stop
Alaska Airlines Logo
3:57 pm - 5:10 pm
IDA
-
STL
24h 13m
1 stop
$454Alaska Airlines
Tue, Sep 15 - Mon, Sep 21
Alaska Airlines Logo
3:19 pm - 1:24 pm
STL
-
IDA
23h 05m
2 stops
Alaska Airlines Logo
3:57 pm - 5:10 pm
IDA
-
STL
24h 13m
1 stop
$466Alaska Airlines
Mon, Aug 3 - Sat, Aug 8
United Airlines Logo
5:10 am - 9:50 am
STL
-
IDA
5h 40m
1 stop
United Airlines Logo
5:54 pm - 11:47 pm
IDA
-
STL
4h 53m
1 stop
$490United Airlines
Booking Insights

KAYAK's insights & trends for St. Louis to Idaho Falls flights

Get data-powered insights and trends into flights from St. Louis to Idaho Falls to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from St. Louis to Idaho Falls?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from St. Louis to Idaho Falls departing in August.

What is the cheapest month to fly from St. Louis to Idaho Falls?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Idaho Falls, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from St. Louis to Idaho Falls is February, where tickets cost $0 (return) on average. On the other hand, the most expensive months are June and November, where the average cost of round-trip tickets is $844 and $810 respectively.

Good to know

Low seasonAugust
Cheapest flight$185
Best time to beat the crowds with an average 30% drop in price.
Most popular time to fly and prices are also 30% lower on average.
Flight from St. Louis to Idaho Falls

When to book flights from St. Louis to Idaho Falls

Are your dates flexible? Find out the best times to travel from St. Louis to Idaho Falls based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from St. Louis to Idaho Falls

  • What is the cheapest flight from St. Louis to Idaho Falls?

    In the last 5 days, the lowest price for a flight from St. Louis to Idaho Falls was $185 for a one-way ticket and $384 for a round-trip.

  • Do I need a passport to fly between St. Louis and Idaho Falls?

    No

  • Which airports will I be using when flying from St. Louis to Idaho Falls?

    St. Louis and Idaho Falls are both served by 1 main airport. You will leave St. Louis from Lambert-St Louis and will be arriving at Idaho Falls Fanning Field.

  • Which aircraft models fly most regularly from St. Louis to Idaho Falls?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from St. Louis to Idaho Falls?

    SkyTeam, and Star Alliance are the airline alliances operating flights between St. Louis and Idaho Falls, with SkyTeam being the most commonly used for this route.

  • How does KAYAK find such low prices on flights from St. Louis to Idaho Falls?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Idaho Falls.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Idaho Falls?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Idaho Falls from St. Louis is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Idaho Falls?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Idaho Falls with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and IDA can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Idaho Falls?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Idaho Falls from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airlines flying from St. Louis to Idaho Falls

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Idaho Falls. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Idaho Falls? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.8
DeltaOverall score based on 8450 reviews
7.2Food
7.8Comfort
8.5Crew
7.8Entertainment
8.1Boarding
Airline reviews

Our flight was delayed by over 4 hours due to a maintenance issue. They announced a new plane was on the way. We were given a $12 food voucher ( airport food is quite expensive You can’t even by a water and a small snack for 12:00. 4 hours later we boarded and landed in Atlanta at 10:20 ish pm. Of course we missed our connection and we were given a hotel voucher and another food voucher ! We didn’t make it home until 11:00 the next day ! Unacceptable

2.0 MediocreAnonymous, Jul 2026
MCI - ATL
Read more Delta reviews

Our flight was delayed by over 4 hours due to a maintenance issue. They announced a new plane was on the way. We were given a $12 food voucher ( airport food is quite expensive You can’t even by a water and a small snack for 12:00. 4 hours later we boarded and landed in Atlanta at 10:20 ish pm. Of course we missed our connection and we were given a hotel voucher and another food voucher ! We didn’t make it home until 11:00 the next day ! Unacceptable

From checking to boarding, it was a seamless experience. The service agents were so helpful. The flight crew was so pleasant.

Delta has too many delays now days. It is 1:06 am now. I was supposed to land in Norfolk at 10:30 pm. I got re-booked through Detroit and I’m still in Detroit. I hope to be landed in Norfolk by 3am. I’ve been in airports for 12 hours as of right now. There is a weather delay now but most delays lately have been maintenance.

This is the first time I've been disappointed with Delta. I was called by Delta to see if I would volunteer to change flights since my original flight home was overbooked. I accepted. The modified booking only provided me a 35 minute layover - when you subtract the fact that boarding closes for a flight 15 minutes early, that gave me 20 minutes to run for one end of the airport to the other. I barely made it. On the 2.5 hour flight to Tampa, the crew repeatedly let us know over the intercom that they cannot serve drinks or snacks due to safety/turbulence. I would have accepted this reason if they did not CONTINUALLY SERVE DRINKS AND COOKED FOOD to First class. If safety is the excuse then the entire plane should be strapped in for safety. On top of this the air conditioning vents were not working correctly and the plane was uncomfortably warm. I love Delta and am a loyal Delta traveler, and I have never had an experience like this. I don't know if there's a disconnect between availability among third-party sites like KAYAK and the airlines or what, but when overbooking causes issues like this for travelers it should be reviewed and changes to the booking process should be made. I blame BOTH KAYAK and Delta for this terrible experience.

Great flight with Delta! Boarding was quick and easy, the amenities were solid, and the plane was in great shape. The flight attendants had a fun, lively energy while staying professional. All in all, a smooth trip — even managed to catch up on some rest. Thanks, Delta!

Having to up charge for a seat assignment is not good. Delta can do better

My flight was canceled after being rescheduled for four days canceling my trip. Kayak and everyone affiliated with it I.e the airlines, and just fly have been excruciating to deal with. My trip to visit family had to be canceled as there was no way to make it. I am furious at all of you.

They delayed our flight because of bad weather in NY which was completely understandable. Then they cancelled our flight and a later flight that evening. The earliest we could fly was the next morning. We ended up buying last minute tickets on another airline and made it home slightly delayed but safely that evening. Delta kept saying it was weather related but if that was the case how did we make it back on another airline? The weather in NY was cloudy but not bad.

The plane smelled like a sewer. Multiple passengers complained. It’s a safety and quality issue to clean these planes.

We were delayed 2 hours leaving STL. I had 20 mins from when we landed in SLC terminal A to make it to SLC terminal B. I had to actually run! thankfully I made my flight but 3/4 legs were delayed to some capacity.

Fine not above and beyond as I had a connection that was delayed due to maintenance

HORRIBLE, my initial flight was cancelled, they made me pay $200 extra dollars and that got cancelled as well! After 6 cancellations I decided to get a refund because I needed to get home to my babies. Out of $1000+ dollars they offered me only $40 in refund! Totally unacceptable! The flight that they cancelled I was able to fly it on another airline. I had to spend $400 on one way tickets just to get home! I’m still getting the runaround.

Flight was delayed. De-icing took a while. When we landed had to wait for another plane to vacate our gate. Just an overall bad experience.

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Our flight was understandably diverted to a small regional airport in Laramie, Wyoming due to weather conditions, which I fully recognize and appreciate. However, the low rating stems from the experience that followed: passengers remained on board for over an hour without the option to deplane and stretch, despite the aircraft being stationary. Although the pilot opened the cabin door, only he was permitted to exit. Meanwhile, passengers grew increasingly uncomfortable as warm summer air entered the cabin through the open door, and being in the second row meant we were impacted immediately. While the flight attendants made efforts to keep everyone at ease, I believe allowing passengers to deplane briefly, given the extended delay, would have significantly improved the overall experience.

Overall a very poor experience - booked premium economy tickets but due to last minute flight delays , all my itinery went for a toss and had to fly economy class with no access to lounge or any compensation by united airlines to make up for the flight delays . i had expected better experience than that from united.

Flight was canceled 12 hours before take-off due to “weather”

We were told our seats were switched which put us in row 1 instead of 12. We were not able to keep our personal items with us. This caused us not to be able to have our gum to pop our ears and we weren’t able to get our iPads out due to the seat belt sign never turning off.

Onboarding - it would be great to see on the screen what group they were boarding. It was very confusing on who was boarding (even though they called it out) they were not clear and the space to board was strange.

Older plane. Food was really bad, almost not worth the effort. Huge difference with European based airlines.

Everything you need to know for your flight from St. Louis to Idaho Falls

Information on your arrival and departure airports