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Cheap flights from Idaho Falls to St. Louis from $150

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 4/4. 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

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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
1:10 pm - 9:31 pm
IDA
-
STL
7h 21m
1 stop
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
$299Delta
Sat, Apr 4 - Tue, Apr 14
Delta Logo
6:55 pm - 9:05 am
IDA
-
STL
13h 10m
2 stops
Delta Logo
6:12 pm - 10:16 pm
STL
-
IDA
5h 04m
1 stop
$304Delta
Sun, Mar 29 - Tue, Apr 7
Delta Logo
6:55 pm - 9:05 am
IDA
-
STL
13h 10m
2 stops
Delta Logo
12:28 pm - 10:16 pm
STL
-
IDA
10h 48m
2 stops
$309Delta
Sun, Mar 29 - Tue, Apr 7
Delta Logo
6:55 pm - 12:21 am
IDA
-
STL
4h 26m
1 stop
Delta Logo
7:15 am - 12:27 pm
STL
-
IDA
6h 12m
1 stop
$314Delta
Tue, Apr 7 - Sat, Apr 11
Delta Logo
5:47 am - 4:50 pm
IDA
-
STL
10h 03m
2 stops
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
$319Delta
Sat, Apr 25 - Tue, May 5
Delta Logo
5:47 am - 4:50 pm
IDA
-
STL
10h 03m
2 stops
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
$324Delta
Sat, Apr 18 - Wed, Apr 22
Delta Logo
5:47 am - 4:50 pm
IDA
-
STL
10h 03m
2 stops
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
$334Delta
Sat, Apr 25 - Sun, May 3
Multiple Airlines Logo
10:06 pm - 9:48 am
IDA
-
STL
34h 42m
2 stops
Multiple Airlines Logo
9:55 pm - 3:27 pm
STL
-
IDA
18h 32m
1 stop
$336Multiple Airlines
Mon, Apr 6 - Thu, Apr 16
Delta Logo
5:47 am - 1:23 pm
IDA
-
STL
6h 36m
1 stop
Delta Logo
6:45 pm - 10:40 pm
STL
-
IDA
4h 55m
1 stop
$345Delta
Tue, Apr 21 - Wed, Apr 29
Delta Logo
6:55 pm - 12:21 am
IDA
-
STL
4h 26m
1 stop
Delta Logo
2:12 pm - 6:15 pm
STL
-
IDA
5h 03m
1 stop
$349Delta
Thu, Mar 26 - Fri, Apr 3

Delta flights from Idaho Falls to St. Louis

Our best Delta deals on Idaho Falls to St. Louis flight tickets
Delta
Apr 4
IDA1:10 pmIdaho Falls Fanning Field
7h 21m
1 stop
STL9:31 pmLambert-St Louis
Apr 11
STL7:15 amLambert-St Louis
6h 12m
1 stop
IDA12:27 pmIdaho Falls Fanning Field
$299
Delta
Mar 29
IDA6:55 pmIdaho Falls Fanning Field
13h 10m
2 stops
STL9:05 amLambert-St Louis
Apr 7
STL6:12 pmLambert-St Louis
5h 04m
1 stop
IDA10:16 pmIdaho Falls Fanning Field
$304
Delta
Mar 29
IDA6:55 pmIdaho Falls Fanning Field
13h 10m
2 stops
STL9:05 amLambert-St Louis
Apr 7
STL12:28 pmLambert-St Louis
10h 48m
2 stops
IDA10:16 pmIdaho Falls Fanning Field
$309

Alaska Airlines flights from Idaho Falls to St. Louis

Our best Alaska Airlines deals on Idaho Falls to St. Louis flight tickets
Alaska Airlines
Apr 22
IDA4:06 pmIdaho Falls Fanning Field
6h 53m
1 stop
STL11:59 pmLambert-St Louis
Apr 29
STL7:00 amLambert-St Louis
9h 29m
1 stop
IDA3:29 pmIdaho Falls Fanning Field
$388
Alaska Airlines
Apr 28
IDA4:06 pmIdaho Falls Fanning Field
6h 53m
1 stop
STL11:59 pmLambert-St Louis
May 2
STL7:00 amLambert-St Louis
9h 29m
1 stop
IDA3:29 pmIdaho Falls Fanning Field
$429
Alaska Airlines
Apr 24
IDA4:06 pmIdaho Falls Fanning Field
6h 53m
1 stop
STL11:59 pmLambert-St Louis
Apr 29
STL7:00 amLambert-St Louis
9h 29m
1 stop
IDA3:29 pmIdaho Falls Fanning Field
$439

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 March 13, 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

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 4/4

1:10 pm-9:31 pm

1 stop7h 21m

Lambert-St Louis

Tue 4/14

6:45 pm-10:40 pm

1 stop4h 55m

$299

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sun 3/29

6:55 pm-9:05 am

2 stops13h 10m

Lambert-St Louis

Tue 4/7

6:12 pm-10:16 pm

1 stop5h 04m

$304

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sun 3/29

6:55 pm-9:05 am

2 stops13h 10m

Lambert-St Louis

Tue 4/7

12:28 pm-10:16 pm

2 stops10h 48m

$309

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 4/7

6:55 pm-12:21 am

1 stop4h 26m

Lambert-St Louis

Sat 4/11

7:15 am-12:27 pm

1 stop6h 12m

$314

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 4/25

5:47 am-4:50 pm

2 stops10h 03m

Lambert-St Louis

Tue 5/5

6:45 pm-10:40 pm

1 stop4h 55m

$319

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 4/18

5:47 am-4:50 pm

2 stops10h 03m

Lambert-St Louis

Wed 4/22

6:45 pm-10:40 pm

1 stop4h 55m

$324

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Sat 4/25

5:47 am-4:50 pm

2 stops10h 03m

Lambert-St Louis

Sun 5/3

6:45 pm-10:40 pm

1 stop4h 55m

$334

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 4/6

10:06 pm-9:48 am

2 stops34h 42m

Lambert-St Louis

Thu 4/16

9:55 pm-3:27 pm

1 stop18h 32m

$336

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Tue 4/21

5:47 am-1:23 pm

1 stop6h 36m

Lambert-St Louis

Wed 4/29

6:45 pm-10:40 pm

1 stop4h 55m

$345
Quickest round-trip

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 3/26

6:55 pm-12:21 am

1 stop4h 26m

Lambert-St Louis

Fri 4/3

2:12 pm-6:15 pm

1 stop5h 03m

$349

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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2

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?

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

In general, April 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 $326. The month of August is another great option to travel to St. Louis, with average flight prices from Idaho Falls averaging around $384.

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 26m

Direct flights

None
The fastest flight from Idaho Falls to St. Louis takes 4h 26m
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

  • 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 26m, 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
American AirlinesPriceFrom $326Free CancellationRating
7.1
11,446 reviews
Search American Airlines flights
United AirlinesPriceFrom $387Free CancellationRating
7.4
9,418 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
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Collinsville
St. Peters
Fenton
Alton
Wentzville
Farmington
Edwardsville
Festus
Clayton
Eureka
Litchfield
Glencoe
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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