STL - IDA

$170 Find Cheap Flights from St. Louis to Idaho Falls

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 8/5. 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

KAYAK searches hundreds of travel sites at once for deals on flights to Idaho Falls

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Idaho Falls, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Idaho Falls, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$359
Typical prices: $490-$470
United Airlines
Sun 9/6Sun 9/6
STL - IDA • 1 stop
Cheapest one-way
$170
American Airlines
Wed 8/5
STL - IDA • 1 stop
Top airlines
Cheapest • from $359 (round-trip)
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
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 17m (one-way)
Insights
Insights
Insights
Insights
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KAYAK searches 100s of sites at once to find you the best travel deals.
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

Sun, Sep 6 - Sun, Sep 6
United Airlines Logo
5:10 am - 9:53 am
STL
-
IDA
5h 43m
1 stop
United Airlines Logo
4:10 pm - 11:50 pm
IDA
-
STL
6h 40m
1 stop
$359United Airlines
Tue, May 19 - Tue, May 26
Alaska Airlines Logo
5:33 pm - 1:17 pm
STL
-
IDA
20h 44m
1 stop
Alaska Airlines Logo
4:03 pm - 4:37 pm
IDA
-
STL
23h 34m
1 stop
$369Alaska Airlines
Sun, Jun 7 - Fri, Jun 12
Multiple Airlines Logo
9:06 pm - 4:08 pm
STL
-
IDA
20h 02m
1 stop
Multiple Airlines Logo
10:56 pm - 2:48 pm
IDA
-
STL
14h 52m
2 stops
$392Multiple Airlines
Tue, May 5 - Tue, May 12
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
6:00 am - 1:32 pm
IDA
-
STL
6h 32m
1 stop
$410Delta
Tue, May 5 - Tue, May 12
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
6:54 pm - 8:10 am
IDA
-
STL
12h 16m
2 stops
$415Delta
Mon, Sep 14 - Fri, Sep 25
Alaska Airlines Logo
5:59 pm - 1:08 pm
STL
-
IDA
20h 09m
1 stop
Alaska Airlines Logo
4:14 pm - 5:03 pm
IDA
-
STL
23h 49m
1 stop
$419Alaska Airlines
Tue, Apr 21 - Sat, Apr 25
Alaska Airlines Logo
3:50 pm - 10:52 pm
STL
-
IDA
8h 02m
1 stop
Alaska Airlines Logo
4:06 pm - 11:59 pm
IDA
-
STL
6h 53m
1 stop
$420Alaska Airlines
Sun, Sep 6 - Sun, Sep 6
United Airlines Logo
5:10 am - 9:53 am
STL
-
IDA
5h 43m
1 stop
United Airlines Logo
2:30 pm - 12:30 am
IDA
-
STL
9h 00m
2 stops
$428United Airlines
Sun, Sep 6 - Sun, Sep 6
United Airlines Logo
5:10 am - 9:53 am
STL
-
IDA
5h 43m
1 stop
United Airlines Logo
2:30 pm - 12:30 am
IDA
-
STL
9h 00m
2 stops
$432United 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
4:10 pm - 11:57 pm
IDA
-
STL
6h 47m
1 stop
$449United 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.

Which airlines provide the cheapest flights from St. Louis to Idaho Falls?

The cheapest round-trip price for the route for each airline clicked by KAYAK users in the last 72 hours.

In the past 3 days, the cheapest round-trip tickets from St. Louis to Idaho Falls were found on United Airlines ($359) and Alaska Airlines ($369).

Good to know

Low seasonAugust
Cheapest flight$170
Best time to beat the crowds with an average 23% drop in price.
Most popular time to fly with an average 1% increase in price.
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 3 days, the lowest price for a flight from St. Louis to Idaho Falls was $170 for a one-way ticket and $359 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.

  • Which is the best airline for flights from St. Louis to Idaho Falls, Delta or United Airlines?

    The two airlines most popular with KAYAK users for flights from St. Louis to Idaho Falls are Delta and United Airlines. With an average price for the route of $384 and an overall rating of 7.9, Delta is the most popular choice. United Airlines is also a great choice for the route, with an average price of $527 and an overall rating of 7.4.

  • 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.
7.9
DeltaOverall score based on 8392 reviews
8.1Boarding
7.8Entertainment
7.9Comfort
8.5Crew
7.2Food
Airline reviews

The crew bent over backwards to thank us for flying and make us comfortable. The food service was quick and efficient. The Captain communicated and said goodbye and thank you as we departed. They really stood out!

10.0 ExcellentKathryn, Apr 2026
JFK - LAX
Read more Delta reviews

The crew bent over backwards to thank us for flying and make us comfortable. The food service was quick and efficient. The Captain communicated and said goodbye and thank you as we departed. They really stood out!

Okay considering we had weather delays which the Pilot notified us of immediately!

Generally on time departures and arrivals, clean planes, sky miles membership provides great benefits (complimentary upgrades, etc).

Flight from Fort Wayne to Atlanta was the smallest in terms of cabin space that I've ever seen. A carry on I've used for 20 years BARELY fit in overhead compartment. I'm 5'10" and felt very cramped. Not the best experience.

I am writing to express my dissatisfaction with the poor service and unprofessional staff we encountered when traveling with an infant. Our flight was delayed, and the gate staff failed to manage the boarding process appropriately. Due to incorrect, unavailable, or missing 'pink tag' stroller and car seat check-in procedures at the gate, we were forced to board last. Furthermore, the gate staff was rude and dismissive, causing significant distress to our infant. To make matters worse, one of our checked items—an infant sleeper/lounger—was returned to us broken. Given the unsafe handling of essential equipment and unprofessional treatment, I expect a prompt resolution regarding compensation for the damaged items.

We departed and landed early which was a nice surprise. The boarding process was slow.

N Everything was perfect from boarding to assistance to baggage in Tampa

Subpar. The seating on the plane is almost unbearable. We are literally touching and/or sitting on each other which is totally unacceptable and shameful. Pilots and crew was very accommodating and friendly.

The boarding was organized and informative but the plane was tight meaning that you were sitting on one another and extremely uncomfortable. It’s disappointing that can’t have common seating comfort on the plane.

Loved the crew! Sucks that we went from 1 hour and 8 minute layover to a 3 hour layover. But weather sucks like that.

Poor communication, flight was delayed for preventable reasons. I missed my connection.

It was better than excellent. The staff in Mason City were great. The young woman that pushed my wheelchair did more than could be expected of her. She came from India 17 years ago. I don't remember her name.

After arriving in Chicago, we were taxiing for 1.5 hours with infrequent and untruthful updates about the amount of time it would take to arrive at the gate. Minimally, the team could have provided timing expectations that were more truthful, especially one their original expectations were not met.

Flights were on time actually early service was good and crew cheerful

Every staff member was professional, friendly and courteous. The pizza twist was ok. It was warm but too much dough.

I had a terrible experience. My flight got delayed from Atlanta to Chicago on Monday April 6, 2026, and that led to me missing my next flight to Brussels. United Airlines didn’t provide me with any accommodation for shelter. I had to sleep at the airport in Chicago. The next flight I was put on didn’t leave until the evening hours of Tuesday 4/7/2026.

Boarding was again a "free for all". We were boarding group 4, and almost the entire plane was able to board before us. It's a shame that someone who follows the rules, gets the short end of the stick. Not fair.

Flight left on time, arrived early, pleasant staff provided water, coffee, etc. access to bathrooms was reasonable and were well maintained. blankets were available, lots of entertainment options. LUGGAGE SERVICE WAS GREAT. I got my one checked bag quickly and was able to make a bus connection for a 2 hour bus ride saving me from waiting another 1.5 hours.

The boarding process was straightforward. One pertinent observation regarding all boarding procedures is that if an individual requires assistance or possesses a special status and is part of preboarding, it is advisable to limit the number of passengers who can preboard with them, rather than the entire, sometimes large, companion groups. The seats are uncomfortable, and the entertainment options are significantly inferior compared to other airlines. During the snack service, I requested an additional bag of snacks, but my request was denied. Initially, the flight attendant agreed to my request.becoming a strange accurate moment. The flight duration was four hours.

The flight was officially delayed 3 times, and was actually later than that. Combined, it was a 3 hour delay, but there was no recognition (miles, voucher, etc). The crew seemed stressed. The captain sounded nervous in his announcements. The flight itself was smooth and uneventful.

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

Information on your arrival and departure airports