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 9/10. 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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Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$319
United Airlines
Sat 8/29Tue 9/1
STL - IDA • 1 stop
Cheapest one-way
$170
Typical prices: $195-$200
Alaska Airlines
Thu 9/10
STL - IDA • 1 stop
Top airlines
Cheapest • from $319 (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 16m (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

Sat, Aug 29 - Tue, Sep 1
United Airlines Logo
5:10 am - 9:53 am
STL
-
IDA
5h 43m
1 stop
United Airlines Logo
5:53 pm - 11:50 pm
IDA
-
STL
4h 57m
1 stop
$319United Airlines
Sun, May 3 - Sat, May 9
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
3:16 pm - 9:06 pm
IDA
-
STL
4h 50m
1 stop
$339Delta
Sun, May 3 - Mon, May 11
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
$344Delta
Tue, May 5 - Sat, May 9
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
$348Delta
Tue, May 5 - Mon, May 11
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
6:54 pm - 9:44 am
IDA
-
STL
13h 50m
2 stops
$353Delta
Mon, May 4 - Sat, May 9
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
3:16 pm - 9:06 pm
IDA
-
STL
4h 50m
1 stop
$354Delta
Mon, May 4 - Tue, May 12
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
3:16 pm - 11:21 pm
IDA
-
STL
7h 05m
2 stops
$359Delta
Thu, May 7 - Mon, May 11
Multiple Airlines Logo
3:33 pm - 3:27 pm
STL
-
IDA
24h 54m
2 stops
Multiple Airlines Logo
10:21 pm - 6:06 pm
IDA
-
STL
18h 45m
1 stop
$368Multiple Airlines
Sun, May 3 - 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
$379Delta
Sat, May 9 - Mon, May 11
Delta Logo
5:00 pm - 10:42 pm
STL
-
IDA
6h 42m
1 stop
Delta Logo
6:54 pm - 8:10 am
IDA
-
STL
12h 16m
2 stops
$384Delta
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 ($319) and Delta ($339).

Good to know

Low seasonAugust
Cheapest flight$170
Best time to beat the crowds with an average 22% drop in price.
Most popular time to fly and prices are also 5% 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 $170 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?

    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 $506 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 8296 reviews
7.9Comfort
8.5Crew
8.1Boarding
7.8Entertainment
7.2Food
Airline reviews

Perhaps when you’re sitting in 1st class and the crew closes the bathroom for the pilots, there could be a notification other than holding your hands up as a blockade when you get there and you’re told the restrooms are closed please turn around … especially at night when visibility is poor and you’re met by a flight attendants with their arms up

10.0 ExcellentDebra, Mar 2026
PBI - ATL
Read more Delta reviews

Perhaps when you’re sitting in 1st class and the crew closes the bathroom for the pilots, there could be a notification other than holding your hands up as a blockade when you get there and you’re told the restrooms are closed please turn around … especially at night when visibility is poor and you’re met by a flight attendants with their arms up

First class is comfortable. Enjoyed a movie and was able to relax compared to coach.

Loved flying First Class. Very comfortable. The seat was amazing. Enjoyed a movie and was able to relax so much better than in coach.

We landed and sat on the tarmac for 45 minutes because they only have one gate at the airport and there was another plane running late so we had to wait

The WiFi was not working. That made for a long flight.

Absolutely no communication on why there's a delay and multiple flight time reschedules. I would have canceled the flight and drove back home if I known it was going to be rescheduled 3 or 4 times.

Another late night flight and MORE men belligerently drinking and yelling. I had to move from first to economy because they were so obnoxious and disruptive. Crazy to go from a cozy chair to cardboard when you were supposed to be in first. Delta allows was too much drinking which leads to belligerent behavior.

I was in first class and literally the men behind me were so aggressively loud I moved myself to economy. This has become so common on Delta - people using audio without headphones, and men on 12am / late night flights drinking and yelling to talk to each other which prevents anyone around them from resting. Pretty crazy to have to move from first to economy (poorer service, less comfort...). Wild wild. Looking into other airlines.

Love delta smaller commuter plane so no entertainment and paid wifi on MKE-LGA leg was extremely unreliable and slow

Stop changing gates. Stop cancelling flights Stop moving my seat.

Both our flights were delayed. Almost didn’t get in the second flight. Staff was rude to the bone.

Both my flight where delayed Had 25min to make it to my transfer flight

Everything was on time and service on the flight was great!

Wifi Bluetooth features for watching in flight movie was horrible. Screen kept blacking out no connection of sound although it said connected. Other than that smooth trip .

The travel company that you have on your site did me so wrong. I don’t know how it happened, but they put my son‘s name on my plane ticket flying to Vietnam. Along with his birthday. They would not have let me fly from Fort Myers to Ho Chi Minh City. I don’t think that I can ever use your service again. I typed my information into the browser along with my passport number and four days before I’m leaving I have to quickly search another ticket to fly out here.

Seats are uncomfortable. This has been a trend in the industry for decades. Trying to fit more seats on each plane to increase profits at the expense of the passenger.

The flight was delayed so we were dead tired, and after that the turbulence was horrible. I was very scared.

It’s always a great time flying with united airlines.

Good flight. Efficient boarding and competent flight crew. No problems until we arrived at our destination gate. We were early so there was an aircraft at the gate that had to move before we could pull in. Then, due to the type of aircraft we flew, the cabin door could not be opened until some luggage from the cargo bay was offloaded to preserve center of gravity characteristics. So, that further delayed deplaning. Despite being 20 minutes early on landing, we ended up being 5 to 10 minutes late after all the delays.

Everything went well except the turbulence what no one have a control of but pilot and crew handled very good!

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

Information on your arrival and departure airports