STL - IDA

$220 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 12/18. 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
$266
Typical prices: $409-$472
Multiple Airlines
Sat 12/6Sat 12/13
STL - IDA • 2 stops
Cheapest one-way
$220
Overall average: $417
American Airlines
Thu 12/18
STL - IDA • 1 stop
Top airlines
Delta
Cheapest • from $353 (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

Sat, Dec 6 - Sat, Dec 13
Multiple Airlines Logo
7:43 pm - 2:36 pmSTL-IDA
43h 53m2 stops
Multiple Airlines Logo
12:49 pm - 12:12 pmIDA-STL
22h 23m1 stop
$266Multiple Airlines
Find Deal
Thu, Jan 15 - Mon, Jan 19
Multiple Airlines Logo
9:47 pm - 2:19 pmSTL-IDA
17h 32m1 stop
Multiple Airlines Logo
9:20 pm - 10:02 amIDA-STL
35h 42m2 stops
$331Multiple Airlines
Find Deal
Sat, Dec 6 - Sat, Dec 13
Delta Logo
5:00 pm - 10:37 pmSTL-IDA
6h 37m1 stop
Delta Logo
6:00 am - 1:30 pmIDA-STL
6h 30m1 stop
$353Delta
Find Deal
Sat, Dec 6 - Sat, Dec 13
Delta Logo
1:00 pm - 10:37 pmSTL-IDA
10h 37m2 stops
Delta Logo
6:00 am - 4:49 pmIDA-STL
9h 49m2 stops
$363Delta
Find Deal
Fri, Jan 16 - Mon, Jan 19
Alaska Airlines Logo
2:50 pm - 10:59 pmSTL-IDA
9h 09m1 stop
Alaska Airlines Logo
9:00 am - 1:54 pmIDA-STL
27h 54m1 stop
$372Alaska Airlines
Find Deal
Tue, Mar 3 - Wed, Mar 4
Delta Logo
10:13 am - 10:21 pmSTL-IDA
13h 08m2 stops
Delta Logo
6:28 pm - 12:24 amIDA-STL
4h 56m1 stop
$384Delta
Find Deal
Tue, Mar 3 - Wed, Mar 4
Alaska Airlines Logo
7:00 am - 4:23 pmSTL-IDA
10h 23m1 stop
Alaska Airlines Logo
5:00 pm - 1:51 pmIDA-STL
19h 51m1 stop
$396Alaska Airlines
Find Deal
Tue, Mar 3 - Wed, Mar 4
Delta Logo
10:13 am - 10:21 pmSTL-IDA
13h 08m2 stops
Delta Logo
6:28 pm - 12:24 amIDA-STL
4h 56m1 stop
$400Delta
Find Deal
Fri, Jan 16 - Mon, Jan 19
United Airlines Logo
8:45 am - 1:30 pmSTL-IDA
5h 45m1 stop
United Airlines Logo
2:40 pm - 8:58 pmIDA-STL
5h 18m1 stop
$452United Airlines
Find Deal
Tue, Mar 3 - Wed, Mar 4
United Airlines Logo
8:21 am - 3:40 pmSTL-IDA
8h 19m2 stops
United Airlines Logo
10:45 am - 9:00 pmIDA-STL
9h 15m2 stops
$469United Airlines
Find Deal
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 December.

What’s the cheapest day of the week to fly from St. Louis to Idaho Falls?

The average price of all round-trip flights from St. Louis to Idaho Falls clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from St. Louis to Idaho Falls, look for departures on Tuesdays and avoid leaving on a Monday, as it's usually the priciest day. When flying back from Idaho Falls, Thursday is the cheapest day to fly and Monday is the most expensive.

Good to know

Cheapest flight$220
Most popular time to fly with an average 5% 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 $220 for a one-way ticket and $266 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 $578 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 8004 reviews
7.9Entertainment
7.9Comfort
8.1Boarding
8.5Crew
7.3Food
Airline reviews

Flight delayed then cancelled. Misplaced luggage. Still do not have. Rented car 1100 mile drive. I had to buy some overnight Hotels clothes toiletries gas food at my expense. Still not home. Not sure where luggage is. Over 4 hours on hold to Felta

2.0 MediocreAnonymous, Nov 2025MOB - ATL
Read more Delta reviews

Flight delayed then cancelled. Misplaced luggage. Still do not have. Rented car 1100 mile drive. I had to buy some overnight Hotels clothes toiletries gas food at my expense. Still not home. Not sure where luggage is. Over 4 hours on hold to Felta

I truly love flying with Delta. They have always treated me with the upmost respect

Our flight attendant in FIRST CLASS was one of the worst I’ve ever had. She was not at all pleasant, nor particularly good at her service.

Everything went well and was good. Nothing exceptional, but no complaints either. Cheap seats are pretty comfortable.

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

They ended up paying for the bag twice, but the counter wouldn't take my baggage receipt. Left it to me to resolve. Not sure how to resolve the issue.

The customer service before board was very rude and when I expressed my concerns about making the connecting flight she laughed and told me I bought the wrong ticket. I explained once it showed the flight was delayed it no longer let me change seats or anything. I was trying to upgrade to make sure I would get to the next gate on time.

Non stop on long haul is the way to go. Great experience

The flight used a B767 with a very old interior from before 2014. The entertainment system did not work at all during the flight despite attempts to reset the system. It was like they flew this route just to be competitive.

They changed planes and the new plane couldn’t carry enough fuel to fly across the country so we had to stop in Kansas City to refuel. Flight was delayed .

Older aircraft, no meal, only food was for purchase. Not impressed United.

United needs to step up their game. Delayed flight leaving Seattle, San Francisco. Older aircraft, not very comfortable.

Always wish for more healthy, gluten free options. We have to bring our own.

Having a long layover, I was very appreciative of the ability to stand by for an earlier flight. Other airlines like Delta have refused this to me in the past, just to be mean (because my ticket class wasn't high enough). United went out of their way to help me get to my destination early, which I really appreciated given that it was the third leg of a 24+ hour journey for me.

Other than a way way too cold cabinets for the entire flight, all was great

One bag is incorrect and not acceptable for an international flight. The food was not just good. I won't fly with them again.

Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?

Plane boarded early a quickly, was mostly full. We left close to on time. And landed early.

Premium Plus is a really good idea for longer flights

7 hours delayed due to operational issues on United’s end. Basically laziness.

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

Information on your arrival and departure airports