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Cheap flights from Idaho Falls to St. Louis from $160

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 2/12. 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
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.
United Airlines Logo
2:40 pm - 8:26 pm
IDA
-
STL
4h 46m
1 stop
United Airlines Logo
4:30 pm - 8:58 pm
STL
-
IDA
5h 28m
1 stop
$371United Airlines
Thu, Feb 12 - Sat, Feb 21
United Airlines Logo
2:40 pm - 8:26 pm
IDA
-
STL
4h 46m
1 stop
United Airlines Logo
9:55 am - 8:58 pm
STL
-
IDA
12h 03m
2 stops
$377United Airlines
Thu, Feb 12 - Sat, Feb 21
United Airlines Logo
2:40 pm - 11:21 pm
IDA
-
STL
7h 41m
1 stop
United Airlines Logo
5:00 am - 3:40 pm
STL
-
IDA
11h 40m
2 stops
$399United Airlines
Wed, Mar 4 - Sat, Mar 14
United Airlines Logo
10:45 am - 10:59 pm
IDA
-
STL
11h 14m
2 stops
United Airlines Logo
5:00 am - 3:40 pm
STL
-
IDA
11h 40m
2 stops
$404United Airlines
Wed, Mar 4 - Sat, Mar 14
United Airlines Logo
2:35 pm - 8:41 pm
IDA
-
STL
5h 06m
1 stop
United Airlines Logo
5:00 am - 3:40 pm
STL
-
IDA
11h 40m
2 stops
$435United Airlines
Thu, Mar 5 - Sat, Mar 14
United Airlines Logo
10:50 am - 9:07 pm
IDA
-
STL
9h 17m
2 stops
United Airlines Logo
5:00 am - 3:40 pm
STL
-
IDA
11h 40m
2 stops
$444United Airlines
Thu, Mar 5 - Sat, Mar 14
United Airlines Logo
2:35 pm - 11:34 pm
IDA
-
STL
7h 59m
1 stop
United Airlines Logo
5:00 am - 3:40 pm
STL
-
IDA
11h 40m
2 stops
$447United Airlines
Thu, Mar 5 - Sat, Mar 14
United Airlines Logo
10:50 am - 10:59 pm
IDA
-
STL
11h 09m
2 stops
United Airlines Logo
5:00 am - 3:40 pm
STL
-
IDA
11h 40m
2 stops
$456United Airlines
Thu, Mar 5 - Sat, Mar 14
Alaska Airlines Logo
8:00 am - 1:51 pm
IDA
-
STL
28h 51m
1 stop
Alaska Airlines Logo
2:47 pm - 4:43 pm
STL
-
IDA
26h 56m
1 stop
$560Alaska Airlines
Mon, Feb 16 - Mon, Feb 23
United Airlines Logo
10:45 am - 10:59 pm
IDA
-
STL
11h 14m
2 stops
United Airlines Logo
8:30 am - 8:58 pm
STL
-
IDA
13h 28m
2 stops
$572United Airlines
Thu, Feb 12 - Sat, Feb 21

United Airlines flights from Idaho Falls to St. Louis

Our best United Airlines deals on Idaho Falls to St. Louis flight tickets
United Airlines
Feb 12
IDA2:40 pmIdaho Falls Fanning Field
4h 46m
1 stop
STL8:26 pmLambert-St Louis
Feb 21
STL4:30 pmLambert-St Louis
5h 28m
1 stop
IDA8:58 pmIdaho Falls Fanning Field
$371
United Airlines
Feb 12
IDA2:40 pmIdaho Falls Fanning Field
4h 46m
1 stop
STL8:26 pmLambert-St Louis
Feb 21
STL9:55 amLambert-St Louis
12h 03m
2 stops
IDA8:58 pmIdaho Falls Fanning Field
$377
United Airlines
Mar 4
IDA2:40 pmIdaho Falls Fanning Field
7h 41m
1 stop
STL11:21 pmLambert-St Louis
Mar 14
STL5:00 amLambert-St Louis
11h 40m
2 stops
IDA3:40 pmIdaho Falls Fanning Field
$399

Alaska Airlines flights from Idaho Falls to St. Louis

Our best Alaska Airlines deals on Idaho Falls to St. Louis flight tickets
Alaska Airlines
Feb 16
IDA8:00 amIdaho Falls Fanning Field
28h 51m
1 stop
STL1:51 pmLambert-St Louis
Feb 23
STL2:47 pmLambert-St Louis
26h 56m
1 stop
IDA4:43 pmIdaho Falls Fanning Field
$560
Alaska Airlines
Feb 12
IDA5:20 pmIdaho Falls Fanning Field
29h 39m
1 stop
STL11:59 pmLambert-St Louis
Feb 16
STL7:00 amLambert-St Louis
17h 36m
1 stop
IDA11:36 pmIdaho Falls Fanning Field
$603
Alaska Airlines
Feb 16
IDA8:00 amIdaho Falls Fanning Field
23h 55m
2 stops
STL8:55 amLambert-St Louis
Feb 23
STL2:47 pmLambert-St Louis
9h 49m
1 stop
IDA11:36 pmIdaho Falls Fanning Field
$652

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 January 29, 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

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 2/12

2:40 pm-8:26 pm

1 stop4h 46m

Lambert-St Louis

Sat 2/21

4:30 pm-8:58 pm

1 stop5h 28m

$371

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 2/12

2:40 pm-8:26 pm

1 stop4h 46m

Lambert-St Louis

Sat 2/21

9:55 am-8:58 pm

2 stops12h 03m

$377

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Wed 3/4

2:40 pm-11:21 pm

1 stop7h 41m

Lambert-St Louis

Sat 3/14

5:00 am-3:40 pm

2 stops11h 40m

$399

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Wed 3/4

10:45 am-10:59 pm

2 stops11h 14m

Lambert-St Louis

Sat 3/14

5:00 am-3:40 pm

2 stops11h 40m

$404

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 3/5

2:35 pm-8:41 pm

1 stop5h 06m

Lambert-St Louis

Sat 3/14

5:00 am-3:40 pm

2 stops11h 40m

$435

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 3/5

10:50 am-9:07 pm

2 stops9h 17m

Lambert-St Louis

Sat 3/14

5:00 am-3:40 pm

2 stops11h 40m

$444

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 3/5

2:35 pm-11:34 pm

1 stop7h 59m

Lambert-St Louis

Sat 3/14

5:00 am-3:40 pm

2 stops11h 40m

$447

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 3/5

10:50 am-10:59 pm

2 stops11h 09m

Lambert-St Louis

Sat 3/14

5:00 am-3:40 pm

2 stops11h 40m

$456

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Mon 2/16

8:00 am-1:51 pm

1 stop28h 51m

Lambert-St Louis

Mon 2/23

2:47 pm-4:43 pm

1 stop26h 56m

$560

Idaho FallsSt. Louis

IDA - STL

IDASTL

Idaho Falls Fanning Field

Thu 2/12

10:45 am-10:59 pm

2 stops11h 14m

Lambert-St Louis

Sat 2/21

8:30 am-8:58 pm

2 stops13h 28m

$572

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 15 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 cheapest month to fly to St. Louis?

In general, August 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 $384. The month of April is another great option to travel to St. Louis, with average flight prices from Idaho Falls averaging around $394.

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

5h 09m

Direct flights

None
The fastest flight from Idaho Falls to St. Louis takes 5h 09m
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 5h 09m, 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
7.2
11,205 reviews
Search American Airlines flights
United AirlinesPriceFrom $387Free CancellationRating
7.4
9,215 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
Maryland Heights
Florissant
O'Fallon
Collinsville
Fenton
St. Peters
Wentzville
Alton
Farmington
Clayton
Edwardsville
Eureka
Festus
Glencoe
Litchfield
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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