STL - IDA

$180 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 7/5. 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
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest round-trip
$308
Alaska Airlines
Mon 8/3Sat 8/8
STL - IDA • 1 stop
Cheapest one-way
$180
Typical prices: $249-$345
United Airlines
Sun 7/5
STL - IDA • 1 stop
Top airlines
Alaska Airlines
Cheapest • from $308 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
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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

Mon, Aug 3 - Sat, Aug 8
Alaska Airlines Logo
6:20 pm - 1:22 pm
STL
-
IDA
20h 02m
1 stop
Alaska Airlines Logo
6:00 am - 2:02 pm
IDA
-
STL
7h 02m
1 stop
$308Alaska Airlines
Wed, Apr 15 - Wed, Apr 22
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
$337Alaska Airlines
Tue, Mar 24 - Tue, Mar 31
United Airlines Logo
5:15 am - 9:56 am
STL
-
IDA
5h 41m
1 stop
United Airlines Logo
2:30 pm - 8:54 pm
IDA
-
STL
5h 24m
1 stop
$339United Airlines
Wed, Apr 15 - Wed, Apr 22
American Airlines Logo
5:20 am - 1:13 pm
STL
-
IDA
8h 53m
1 stop
American Airlines Logo
1:43 pm - 8:24 am
IDA
-
STL
17h 41m
2 stops
$349American Airlines
Tue, Mar 17 - Tue, Mar 24
United Airlines Logo
5:15 am - 9:56 am
STL
-
IDA
5h 41m
1 stop
United Airlines Logo
2:35 pm - 8:41 pm
IDA
-
STL
5h 06m
1 stop
$375United Airlines
Tue, Mar 3 - Wed, Mar 4
United Airlines Logo
8:41 am - 1:30 pm
STL
-
IDA
5h 49m
1 stop
United Airlines Logo
2:40 pm - 11:21 pm
IDA
-
STL
7h 41m
1 stop
$383United Airlines
Mon, Aug 3 - Sat, Aug 8
United Airlines Logo
5:15 am - 9:55 am
STL
-
IDA
5h 40m
1 stop
United Airlines Logo
6:03 pm - 11:58 pm
IDA
-
STL
4h 55m
1 stop
$388United Airlines
Tue, Mar 3 - Wed, Mar 4
United Airlines Logo
8:41 am - 1:30 pm
STL
-
IDA
5h 49m
1 stop
United Airlines Logo
5:33 pm - 11:21 pm
IDA
-
STL
4h 48m
1 stop
$400United Airlines
Tue, Mar 3 - Wed, Mar 4
United Airlines Logo
7:41 am - 3:40 pm
STL
-
IDA
8h 59m
2 stops
United Airlines Logo
2:40 pm - 11:21 pm
IDA
-
STL
7h 41m
1 stop
$405United Airlines
Wed, Apr 15 - Wed, Apr 22
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
5:47 am - 4:50 pm
IDA
-
STL
10h 03m
2 stops
$407Delta
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 Alaska Airlines ($308) and United Airlines ($339).

Find deals

Good to know

Low seasonAugust
Cheapest flight$180
Best time to beat the crowds with an average 27% drop in price.
Most popular time to fly and prices are also 4% 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 3 days, the lowest price for a flight from St. Louis to Idaho Falls was $180 for a one-way ticket and $308 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 $585 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 8203 reviews
7.9Comfort
7.2Food
8.5Crew
7.8Entertainment
8.1Boarding
Airline reviews

Flight was delayed and no reasons provided. After the passengers were boarded, the crew made announcement that the captain has jot arrived and he would take another 15 mins. All passengers patiently sat until the captain came and started. Terrible experience!

2.0 MediocreMansoor, Feb 2026
DTW - RIC
Read more Delta reviews

Flight was delayed and no reasons provided. After the passengers were boarded, the crew made announcement that the captain has jot arrived and he would take another 15 mins. All passengers patiently sat until the captain came and started. Terrible experience!

Flight was delayed. No information on why it was delayed. After we boarded the flight, , the crew made announcement that the captain hs not arrived and he will take 15 mins more to arrive. Passengers were just sitting patiently for the captain to arrive and start, Terrible experience.

Totally worth the miles to upgrade to Delta Comfort. Plenty of legroom.

This was my first time flying Delta ever and I had a great experience!

Smallest leg room I've ever had on a plane.

They took all carry-on luggage from Groups 6 -9 - I was group 5 and waiting in line to board - they made me check my luggage too. That then went to baggage claim and delayed departure from the airport. There was overhead room in my seating area - Delta over reacted. Also, had a gentleman next to me that took up 1/2 my seat.

Flight delay was frustrating, also you cannot checkin online without delta app, web browser check-in throw errors

The gate agent was most helpful in getting me on to fly standby. I greatly appreciate it.

bulkhead seat had very little legroom - even in bsiness class.

The plane was an older model, so it wasn’t as comfortable as others. The flight attendants were not helpful during onboarding. It was a full flight so there was chaos finding space for baggage.

Very old flight - time to retire it for newer airplanes

2+ hours delayed Outlet in row 12 did not work Tv monitors did not work Lights kept off the entire flight for at 5pm-7pm flight

Very disappointing given gate agent behavior. Filed a formal complaint with United.

Do not like the size of the overhead bin. I think staff should monitor the size of suitcases that are being carried on by passengers to ensure they meet the size requirement.

Crew was great (professional, attentive, prompt). Snacks for 4 hrs flight is deplorable.

Flight delayed. WiFi connectivity very poor if not existant. Last minute arrival forced me to run to catch my connection.

Both of my flights arrived early and check in process was smooth

Terrible. No customer service, no food, no drinks on a 6 hour premier economy booking.

Short flight, but no drink/snack service. The flights both going and coming were delayed.

Much better than Spirit. I was please by the easy fast check in and boarding

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

Information on your arrival and departure airports

St. Louis (STL)
Idaho Falls (IDA)