STL - IDA

$212 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 8/20. 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

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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41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest round-trip
$319
Typical prices: $844-$538
Alaska Airlines
Sat 11/14Wed 11/18
STL - IDA • 1 stop
Cheapest one-way
$212
Multiple Airlines
Thu 8/20
STL - IDA • 1 stop
Top airlines
Cheapest • from $319 (round-trip)
Best reviews • 7.4 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 41m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 100% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
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, Nov 14 - Wed, Nov 18
Alaska Airlines Logo
7:00 am - 3:17 pm
STL
-
IDA
9h 17m
1 stop
Alaska Airlines Logo
6:04 am - 2:15 pm
IDA
-
STL
7h 11m
1 stop
$319Alaska Airlines
Fri, Aug 14 - Mon, Aug 17
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
Thu, Oct 1 - Thu, Oct 8
United Airlines Logo
5:10 am - 9:53 am
STL
-
IDA
5h 43m
1 stop
United Airlines Logo
4:04 pm - 11:45 pm
IDA
-
STL
6h 41m
1 stop
$364United Airlines
Wed, Sep 23 - Sat, Sep 26
Alaska Airlines Logo
6:08 pm - 1:24 pm
STL
-
IDA
20h 16m
1 stop
Alaska Airlines Logo
3:57 pm - 5:10 pm
IDA
-
STL
24h 13m
1 stop
$369Alaska Airlines
Wed, Aug 5 - Mon, Aug 10
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
Tue, Jun 16 - Fri, Jun 19
United Airlines Logo
5:10 am - 9:50 am
STL
-
IDA
5h 40m
1 stop
United Airlines Logo
5:54 pm - 11:57 pm
IDA
-
STL
5h 03m
1 stop
$389United Airlines
Thu, Jul 9 - Mon, Jul 13
United Airlines Logo
5:10 am - 9:50 am
STL
-
IDA
5h 40m
1 stop
United Airlines Logo
5:54 pm - 11:57 pm
IDA
-
STL
5h 03m
1 stop
$395United Airlines
Thu, Jul 9 - Mon, Jul 13
United Airlines Logo
5:10 am - 9:50 am
STL
-
IDA
5h 40m
1 stop
United Airlines Logo
5:54 pm - 11:57 pm
IDA
-
STL
5h 03m
1 stop
$396United Airlines
Sat, Jul 4 - Wed, Jul 8
Delta Logo
5:00 pm - 10:31 pm
STL
-
IDA
6h 31m
1 stop
Delta Logo
7:00 pm - 12:41 am
IDA
-
STL
4h 41m
1 stop
$405Delta
Sat, Nov 14 - Wed, Nov 18
United Airlines Logo
9:23 am - 5:22 pm
STL
-
IDA
8h 59m
2 stops
United Airlines Logo
2:35 pm - 8:59 pm
IDA
-
STL
5h 24m
1 stop
$414United 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 November.

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 November and June, where the average cost of round-trip tickets is $702 and $688 respectively.

Good to know

Low seasonAugust
Cheapest flight$212
Best time to beat the crowds with an average 26% drop in price.
Most popular time to fly with an average 26% 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 5 days, the lowest price for a flight from St. Louis to Idaho Falls was $212 for a one-way ticket and $319 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?

    Star Alliance is the only airline alliance operating flights between St. Louis and Idaho Falls.

  • 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 airline 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.
7.4
United AirlinesOverall score based on 9775 reviews
7.7Boarding
7.3Comfort
8.1Crew
7.1Entertainment
6.6Food
Airline reviews

Even through the flight was delayed due to storms near IAH The flight was great! The crew was so hospitable and professional

10.0 ExcellentAnonymous, Jun 2026
GSP - IAH
Read more United Airlines reviews

Even through the flight was delayed due to storms near IAH The flight was great! The crew was so hospitable and professional

I flew from Santa Fe to Denver to catch a flight to London and the transfer of my luggage on arrival at Denver to the London flight worked perfectly. The crew on the ground and on board for the London flight were so friendly and efficient.

Boarded early; and arrived home 40 mins early. After a long flight, it’s nice to be back home early. These flights have no amenities; no snacks. So need to bring your own

Boarded early, left early, arrived 40 mins early! A win win for me!

New plane was lovely. Crew customer service is always lax but expected. Kraft on time and arrived safely.

These airplanes should be illegal. The seats are two tight, it is a safety issue. Wheelchair support was ridiculously slow. We almost missed our flight.

It was a short flight so I was expecting too much

Horrifying Almost 2 million miles. Bring your own food and drink. One coffee or drink every three hours. Have to order meals on app more than 24 hours ahead Tiny and dirty bathrooms

Flight was delayed but more than 90 minutes. This caused me to miss my available windows for pick-up by a friend. I had to pay $125 for an uber back home from the airport which was an added expense that I had not budgeted for my trip. Staff was friendly.

Seat pitch is horrible especially on the 15 hour flight. Gate crew at SFO was Outstanding. The flight crew was also great.

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

Information on your arrival and departure airports