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Cheap flights from St. Louis to Idaho Falls from $316

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Idaho Falls departing on 7/5. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from St. Louis to Idaho Falls

Cheap round-trip flights

Enter your travel dates to find the best prices.
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
Delta Logo
6:54 pm - 9:49 am
IDA
-
STL
13h 55m
2 stops
$359Delta
Tue, May 5 - Fri, May 8
Multiple Airlines Logo
9:21 pm - 10:10 am
STL
-
IDA
13h 49m
1 stop
Multiple Airlines Logo
10:56 pm - 7:23 pm
IDA
-
STL
19h 27m
2 stops
$360Multiple Airlines
Sun, May 31 - Fri, Jun 5
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
Mon, Jun 1 - Thu, Jun 4
Delta Logo
8:00 am - 2:41 pm
STL
-
IDA
7h 41m
1 stop
Delta Logo
6:00 am - 1:36 pm
IDA
-
STL
6h 36m
1 stop
$379Delta
Sat, Jun 27 - Sat, Jul 4
United Airlines Logo
8:46 am - 1:25 pm
STL
-
IDA
5h 39m
1 stop
United Airlines Logo
2:31 pm - 8:43 pm
IDA
-
STL
5h 12m
1 stop
$382United Airlines
Tue, May 5 - Fri, May 8
Multiple Airlines Logo
9:21 pm - 10:10 am
STL
-
IDA
13h 49m
1 stop
Multiple Airlines Logo
10:56 pm - 8:26 pm
IDA
-
STL
20h 30m
1 stop
$411Multiple Airlines
Sun, May 31 - Fri, Jun 5
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
$414United Airlines
Wed, May 27 - Thu, Jun 11
Delta Logo
1:46 pm - 10:40 pm
STL
-
IDA
9h 54m
2 stops
Delta Logo
6:54 pm - 8:19 am
IDA
-
STL
12h 25m
2 stops
$417Delta
Tue, May 5 - Fri, May 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
$429United Airlines
Sun, May 31 - Wed, Jun 3
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
$465United Airlines
Sun, May 31 - Thu, Jun 4

Alaska Airlines flights from St. Louis to Idaho Falls

Our best Alaska Airlines deals on St. Louis to Idaho Falls flight tickets
Alaska Airlines
Jun 1
STL5:33 pmLambert-St Louis
20h 44m
1 stop
IDA1:17 pmIdaho Falls Fanning Field
Jun 4
IDA4:03 pmIdaho Falls Fanning Field
23h 34m
1 stop
STL4:37 pmLambert-St Louis
$369
Alaska Airlines
Jun 1
STL5:33 pmLambert-St Louis
20h 44m
1 stop
IDA1:17 pmIdaho Falls Fanning Field
Jun 5
IDA1:54 pmIdaho Falls Fanning Field
9h 00m
1 stop
STL11:54 pmLambert-St Louis
$497
Alaska Airlines
Apr 20
STL7:00 amLambert-St Louis
10h 19m
1 stop
IDA4:19 pmIdaho Falls Fanning Field
Apr 22
IDA4:06 pmIdaho Falls Fanning Field
6h 53m
1 stop
STL11:59 pmLambert-St Louis
$499

Delta flights from St. Louis to Idaho Falls

Our best Delta deals on St. Louis to Idaho Falls flight tickets
Delta
May 5
STL6:45 pmLambert-St Louis
4h 55m
1 stop
IDA10:40 pmIdaho Falls Fanning Field
May 8
IDA6:54 pmIdaho Falls Fanning Field
13h 55m
2 stops
STL9:49 amLambert-St Louis
$359
Delta
Jun 27
STL8:00 amLambert-St Louis
7h 41m
1 stop
IDA2:41 pmIdaho Falls Fanning Field
Jul 4
IDA6:00 amIdaho Falls Fanning Field
6h 36m
1 stop
STL1:36 pmLambert-St Louis
$379
Delta
May 5
STL1:46 pmLambert-St Louis
9h 54m
2 stops
IDA10:40 pmIdaho Falls Fanning Field
May 8
IDA6:54 pmIdaho Falls Fanning Field
12h 25m
2 stops
STL8:19 amLambert-St Louis
$417

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Idaho Falls that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated March 28, 2026.
Use the filters below to find and compare flights from St. Louis to Idaho Falls that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 5/5

6:45 pm-10:40 pm

1 stop4h 55m

Idaho Falls Fanning Field

Fri 5/8

6:54 pm-9:49 am

2 stops13h 55m

$359

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 5/31

9:21 pm-10:10 am

1 stop13h 49m

Idaho Falls Fanning Field

Fri 6/5

10:56 pm-7:23 pm

2 stops19h 27m

$360

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Mon 6/1

5:33 pm-1:17 pm

1 stop20h 44m

Idaho Falls Fanning Field

Thu 6/4

4:03 pm-4:37 pm

1 stop23h 34m

$369

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 6/27

8:00 am-2:41 pm

1 stop7h 41m

Idaho Falls Fanning Field

Sat 7/4

6:00 am-1:36 pm

1 stop6h 36m

$379
Quickest round-trip

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 5/5

8:46 am-1:25 pm

1 stop5h 39m

Idaho Falls Fanning Field

Fri 5/8

2:31 pm-8:43 pm

1 stop5h 12m

$382

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 5/31

9:21 pm-10:10 am

1 stop13h 49m

Idaho Falls Fanning Field

Fri 6/5

10:56 pm-8:26 pm

1 stop20h 30m

$411

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Wed 5/27

5:10 am-9:50 am

1 stop5h 40m

Idaho Falls Fanning Field

Thu 6/11

4:10 pm-11:57 pm

1 stop6h 47m

$414

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 5/5

1:46 pm-10:40 pm

2 stops9h 54m

Idaho Falls Fanning Field

Fri 5/8

6:54 pm-8:19 am

2 stops12h 25m

$417

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 5/31

5:10 am-9:50 am

1 stop5h 40m

Idaho Falls Fanning Field

Wed 6/3

4:10 pm-11:57 pm

1 stop6h 47m

$429

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sun 5/31

5:10 am-9:50 am

1 stop5h 40m

Idaho Falls Fanning Field

Thu 6/4

4:10 pm-11:57 pm

1 stop6h 47m

$465

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 14 resultsSorted by cheapest first
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See travel insights to Idaho Falls from

How to get the cheapest flight ticket from St. Louis to Idaho Falls

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest airline that flies from Lambert-St Louis to Idaho Falls Fanning Field?

American Airlines and United Airlines are the most popular carriers operating from Lambert-St Louis to Idaho Falls Fanning Field

What airlines fly to Idaho Falls?

United Airlines, American Airlines and Delta are the top three most popular airlines that fly to Idaho Falls from St. Louis according to our data. United Airlines is the first choice among our users, with 53% of people opting to fly with this airline when traveling to Idaho Falls. Keep in mind that there are 3 different airlines that fly to Idaho Falls on a routine basis, so you have a few additional options to choose from.

When to book flights from St. Louis to Idaho Falls

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Idaho Falls according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Idaho Falls (STL to IDA) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Idaho Falls

Fastest flight time

5h 30m

Direct flights

None
The fastest flight from St. Louis to Idaho Falls takes 5h 30m
There are no direct flights from St. Louis to Idaho Falls. There are no popular flight routes from St. Louis to Idaho Falls.
Search flight deals

  • How far is Lambert-St Louis to Idaho Falls Fanning Field by plane?

    The straight-line distance from Lambert-St Louis to Idaho Falls Fanning Field is 1181.2 mi. 5h 30m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport?

    Prices for flights from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport.

  • What documentation or ID do you need to fly to Idaho Falls Fanning Field Airport?

    The travel and health documents required for your trip to Idaho Falls Fanning Field Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Idaho Falls Fanning Field Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular airline from St. Louis to Idaho Falls?

Best airlines flying from St. Louis to Idaho Falls

Compare and see reviews for airlines that fly from St. Louis to Idaho Falls with momondo
Airline
Rating
Free Cancellation
Price
DeltaPriceFrom $163Free CancellationRating
7.9
8,356 reviews
Search Delta flights
United AirlinesPriceFrom $338Free CancellationRating
7.4
9,499 reviews
Search United Airlines flights

Traveling to a place near Idaho Falls?

Book flights to Idaho Falls if you plan to visit one of these locations
Rexburg

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Idaho Falls?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from St. Louis to Idaho Falls. momondo saves you time and could save you money on your trip.

Can I find flights from St. Louis to Idaho Falls with flexible booking policies on momondo?

momondo does allow users to show only those flights to Idaho Falls from St. Louis which offer a flexible booking policy as well as other useful filters and features.

How can momondo help me find flights from St. Louis to Idaho Falls?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Idaho Falls.

I’m not ready to book a flight from St. Louis to Idaho Falls right now. Can momondo alert me if prices change?

Yes. momondo can track prices for St. Louis to Idaho Falls flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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