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Cheap flights from Idaho Falls to St. Louis from $165

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Idaho Falls to St. Louis departing on 9/12. 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
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Idaho Falls to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Delta Logo
6:57 pm - 12:44 am
IDA
-
STL
4h 47m
1 stop
Delta Logo
7:45 am - 12:22 pm
STL
-
IDA
5h 37m
1 stop
$329Delta
Fri, Oct 2 - Wed, Oct 7
Delta Logo
7:00 pm - 12:41 am
IDA
-
STL
4h 41m
1 stop
Delta Logo
5:00 pm - 10:32 pm
STL
-
IDA
6h 32m
1 stop
$329Delta
Tue, Aug 25 - Tue, Sep 1
American Airlines Logo
2:20 pm - 11:42 pm
IDA
-
STL
8h 22m
1 stop
American Airlines Logo
6:00 am - 1:09 pm
STL
-
IDA
8h 09m
1 stop
$329American Airlines
Tue, Aug 25 - Tue, Sep 1
Delta Logo
7:00 pm - 12:41 am
IDA
-
STL
4h 41m
1 stop
Delta Logo
3:50 pm - 10:32 pm
STL
-
IDA
7h 42m
2 stops
$334Delta
Tue, Aug 25 - Tue, Sep 1
Delta Logo
6:00 am - 1:38 pm
IDA
-
STL
6h 38m
1 stop
Delta Logo
11:00 am - 10:32 pm
STL
-
IDA
12h 32m
2 stops
$354Delta
Tue, Aug 25 - Tue, Sep 1
Alaska Airlines Logo
4:14 pm - 4:37 pm
IDA
-
STL
23h 23m
1 stop
Alaska Airlines Logo
7:56 pm - 3:20 pm
STL
-
IDA
20h 24m
1 stop
$379Alaska Airlines
Fri, Aug 14 - Tue, Aug 18
Alaska Airlines Logo
6:09 am - 3:44 pm
IDA
-
STL
8h 35m
1 stop
Alaska Airlines Logo
7:02 am - 3:20 pm
STL
-
IDA
9h 18m
1 stop
$379Alaska Airlines
Sat, Oct 24 - Wed, Oct 28
United Airlines Logo
4:04 pm - 11:40 pm
IDA
-
STL
6h 36m
1 stop
United Airlines Logo
9:00 am - 3:23 pm
STL
-
IDA
7h 23m
1 stop
$409United Airlines
Sat, Aug 15 - Wed, Aug 19
United Airlines Logo
2:25 pm - 8:46 pm
IDA
-
STL
5h 21m
1 stop
United Airlines Logo
4:40 pm - 9:18 pm
STL
-
IDA
5h 38m
1 stop
$419United Airlines
Thu, Aug 27 - Mon, Aug 31
United Airlines Logo
4:05 pm - 11:44 pm
IDA
-
STL
6h 39m
1 stop
United Airlines Logo
6:00 am - 3:38 pm
STL
-
IDA
10h 38m
2 stops
$424United Airlines
Sat, Oct 24 - Wed, Oct 28

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Delta flights from Idaho Falls to St. Louis

Our best Delta deals on Idaho Falls to St. Louis flight tickets
Delta
Aug 25
IDA7:00 pmIdaho Falls Fanning Field
4h 41m
1 stop
STL12:41 amLambert-St Louis
Sep 1
STL5:00 pmLambert-St Louis
6h 32m
1 stop
IDA10:32 pmIdaho Falls Fanning Field
$329
Delta
Aug 25
IDA7:00 pmIdaho Falls Fanning Field
4h 41m
1 stop
STL12:41 amLambert-St Louis
Sep 1
STL3:50 pmLambert-St Louis
7h 42m
2 stops
IDA10:32 pmIdaho Falls Fanning Field
$334
Delta
Aug 25
IDA6:00 amIdaho Falls Fanning Field
6h 38m
1 stop
STL1:38 pmLambert-St Louis
Sep 1
STL11:00 amLambert-St Louis
12h 32m
2 stops
IDA10:32 pmIdaho Falls Fanning Field
$354

United Airlines flights from Idaho Falls to St. Louis

Our best United Airlines deals on Idaho Falls to St. Louis flight tickets
United Airlines
Aug 15
IDA4:04 pmIdaho Falls Fanning Field
6h 36m
1 stop
STL11:40 pmLambert-St Louis
Aug 19
STL9:00 amLambert-St Louis
7h 23m
1 stop
IDA3:23 pmIdaho Falls Fanning Field
$409
United Airlines
Aug 27
IDA2:25 pmIdaho Falls Fanning Field
5h 21m
1 stop
STL8:46 pmLambert-St Louis
Aug 31
STL4:40 pmLambert-St Louis
5h 38m
1 stop
IDA9:18 pmIdaho Falls Fanning Field
$419
United Airlines
Aug 27
IDA4:04 pmIdaho Falls Fanning Field
6h 27m
1 stop
STL11:31 pmLambert-St Louis
Aug 31
STL7:00 amLambert-St Louis
15h 18m
2 stops
IDA9:18 pmIdaho Falls Fanning Field
$424

momondo Fare Finder

 
Customize your flight search to find flights from Idaho Falls to St. Louis 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 August 3, 2026.
Use the filters below to find and compare flights from Idaho Falls to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 10/2

6:57 pm-12:44 am

1 stop4h 47m

Lambert-St Louis

Wed 10/7

7:45 am-12:22 pm

1 stop5h 37m

$329

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 8/25

7:00 pm-12:41 am

1 stop4h 41m

Lambert-St Louis

Tue 9/1

5:00 pm-10:32 pm

1 stop6h 32m

$329

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 8/25

2:20 pm-11:42 pm

1 stop8h 22m

Lambert-St Louis

Tue 9/1

6:00 am-1:09 pm

1 stop8h 09m

$329

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 8/25

7:00 pm-12:41 am

1 stop4h 41m

Lambert-St Louis

Tue 9/1

3:50 pm-10:32 pm

2 stops7h 42m

$334

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 8/25

6:00 am-1:38 pm

1 stop6h 38m

Lambert-St Louis

Tue 9/1

11:00 am-10:32 pm

2 stops12h 32m

$354

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Fri 8/14

4:14 pm-4:37 pm

1 stop23h 23m

Lambert-St Louis

Tue 8/18

7:56 pm-3:20 pm

1 stop20h 24m

$379

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 10/24

6:09 am-3:44 pm

1 stop8h 35m

Lambert-St Louis

Wed 10/28

7:02 am-3:20 pm

1 stop9h 18m

$379

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 8/15

4:04 pm-11:40 pm

1 stop6h 36m

Lambert-St Louis

Wed 8/19

9:00 am-3:23 pm

1 stop7h 23m

$409

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 8/27

2:25 pm-8:46 pm

1 stop5h 21m

Lambert-St Louis

Mon 8/31

4:40 pm-9:18 pm

1 stop5h 38m

$419

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 10/24

4:05 pm-11:44 pm

1 stop6h 39m

Lambert-St Louis

Wed 10/28

6:00 am-3:38 pm

2 stops10h 38m

$424

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

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

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 typical price of a round-trip flight between Idaho Falls and St. Louis?

Prices are currently low for flights on this route.

Typical prices usually range from $475 to $510.
The lowest price recently found on this route was $329.

What is the cheapest month to fly to St. Louis?

In general, May is the cheapest month to fly from Idaho Falls to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $443. The month of September is another great option to travel to St. Louis, with average flight prices from Idaho Falls averaging around $480.

When to book flights from Idaho Falls to St. Louis

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

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

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

Fastest flight time

4h 34m

Direct flights

None
The fastest flight from Idaho Falls to St. Louis takes 4h 34m
There are no direct flights from Idaho Falls to St. Louis. There are no popular flight routes from Idaho Falls to St. Louis.
Search flight deals

Frequently asked questions about flying from Idaho Falls to St. Louis

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

    Lambert-St Louis is 1181.2 mi away from Idaho Falls Fanning Field. Flights usually cover this in 4h 34m, depending on flying conditions and air traffic around both airports.

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

    Prices for flights from Idaho Falls Fanning Field Airport to Lambert-St Louis Airport are updated daily.

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

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

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Idaho Falls Fanning Field Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The necessary travel and health documents for your Lambert-St Louis Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

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

Best airlines flying from Idaho Falls to St. Louis

Compare and see reviews for airlines that fly from Idaho Falls to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
DeltaPriceFrom $185Free CancellationRating
7.8
8,483 reviews
Search Delta flights
United AirlinesPriceFrom $387Free CancellationRating
7.4
10,058 reviews
Search United Airlines flights

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Fairview Heights
Hermann
St. Peters
Maryland Heights
Florissant
Collinsville
Alton
O'Fallon
Clayton
Farmington
Fenton
Wentzville
Festus
Eureka
Edwardsville
Litchfield
Grafton
Shrewsbury

Why use momondo?

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

Finding the right flight to St. Louis from Idaho Falls is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to St. Louis quick and easy, saving you time and money.

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

Yes. All flights to St. Louis from Idaho Falls on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

momondo helps you find the best flight between Idaho Falls and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

Yes momondo offers price alerts on flights to St. Louis from Idaho Falls. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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