What airlines fly to Idaho Falls?

United Airlines, Delta and American Airlines 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 46% 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 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?

The number of operators available for flights from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport is 2 as of December 2025.

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.

$342 Cheap Flights from St. Louis to Idaho Falls in 2025/26

1 adult

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Find the cheapest flights from St. Louis to Idaho Falls

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One-way

Cheap round-trip flights

Enter your travel dates to find the best prices.

2:50 pm - 10:59 pm

STL

IDA

9h 09m1 stop

6:58 pm - 1:54 pm

IDA

STL

17h 56m1 stop

$342Alaska Airlines

ven., janv. 30 - sam., janv. 31

2:50 pm - 10:59 pm

STL

IDA

9h 09m1 stop

6:58 pm - 1:54 pm

IDA

STL

17h 56m1 stop

$353Alaska Airlines

lun., janv. 26 - jeu., janv. 29

2:50 pm - 10:59 pm

STL

IDA

9h 09m1 stop

6:58 pm - 1:54 pm

IDA

STL

17h 56m1 stop

$357Alaska Airlines

mer., févr. 4 - sam., févr. 7

2:50 pm - 10:59 pm

STL

IDA

9h 09m1 stop

9:00 am - 1:54 pm

IDA

STL

27h 54m1 stop

$368Alaska Airlines

mer., févr. 4 - sam., févr. 7

6:04 pm - 10:20 pm

STL

IDA

5h 16m1 stop

6:59 pm - 8:52 am

IDA

STL

12h 53m2 stops

$393Delta

lun., mars 9 - ven., mars 13

3:25 pm - 10:20 pm

STL

IDA

7h 55m2 stops

6:59 pm - 8:52 am

IDA

STL

12h 53m2 stops

$425Delta

lun., mars 9 - ven., mars 13

8:45 am - 1:30 pm

STL

IDA

5h 45m1 stop

2:40 pm - 8:58 pm

IDA

STL

5h 18m1 stop

$433United Airlines

ven., janv. 9 - dim., janv. 11

11:20 am - 9:16 pm

STL

IDA

10h 56m2 stops

2:40 pm - 8:58 pm

IDA

STL

5h 18m1 stop

$438United Airlines

ven., janv. 9 - dim., janv. 11

5:30 am - 9:56 am

STL

IDA

5h 26m1 stop

2:35 pm - 8:55 pm

IDA

STL

5h 20m1 stop

$451United Airlines

lun., mars 9 - ven., mars 13

11:20 am - 9:14 pm

STL

IDA

10h 54m2 stops

6:30 am - 1:16 pm

IDA

STL

5h 46m1 stop

$473United Airlines

mer., févr. 4 - sam., févr. 7

Alaska Airlines flights from St. Louis to Idaho Falls

Our best Alaska Airlines deals on St. Louis to Idaho Falls flight tickets

Alaska Airlines

Jan 30

STL2:50 pmLambert-St Louis

9h 09m

1 stop

IDA10:59 pmIdaho Falls Fanning Field

Jan 31

IDA6:58 pmIdaho Falls Fanning Field

17h 56m

1 stop

STL1:54 pmLambert-St Louis

$342

Find similar

Alaska Airlines

Jan 26

STL2:50 pmLambert-St Louis

9h 09m

1 stop

IDA10:59 pmIdaho Falls Fanning Field

Jan 29

IDA6:58 pmIdaho Falls Fanning Field

17h 56m

1 stop

STL1:54 pmLambert-St Louis

$353

Find similar

Alaska Airlines

Feb 4

STL2:50 pmLambert-St Louis

9h 09m

1 stop

IDA10:59 pmIdaho Falls Fanning Field

Feb 7

IDA6:58 pmIdaho Falls Fanning Field

17h 56m

1 stop

STL1:54 pmLambert-St Louis

$357

Find similar

Delta flights from St. Louis to Idaho Falls

Our best Delta deals on St. Louis to Idaho Falls flight tickets

Delta

Mar 9

STL6:04 pmLambert-St Louis

5h 16m

1 stop

IDA10:20 pmIdaho Falls Fanning Field

Mar 13

IDA6:59 pmIdaho Falls Fanning Field

12h 53m

2 stops

STL8:52 amLambert-St Louis

$393

Find similar

Delta

Mar 9

STL3:25 pmLambert-St Louis

7h 55m

2 stops

IDA10:20 pmIdaho Falls Fanning Field

Mar 13

IDA6:59 pmIdaho Falls Fanning Field

12h 53m

2 stops

STL8:52 amLambert-St Louis

$425

Find similar

Delta

Jan 26

STL3:31 pmLambert-St Louis

8h 26m

2 stops

IDA10:57 pmIdaho Falls Fanning Field

Jan 29

IDA5:25 amIdaho Falls Fanning Field

7h 23m

1 stop

STL1:48 pmLambert-St Louis

$524

Find similar

Fly from

Fly to

Route

Depart

Return

Price

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

ven. 1/30

2:50 pm-10:59 pm

1 stop9h 09m

Idaho Falls Fanning Field

sam. 1/31

6:58 pm-1:54 pm

1 stop17h 56m

$342

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 1/26

2:50 pm-10:59 pm

1 stop9h 09m

Idaho Falls Fanning Field

jeu. 1/29

6:58 pm-1:54 pm

1 stop17h 56m

$353

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

mer. 2/4

2:50 pm-10:59 pm

1 stop9h 09m

Idaho Falls Fanning Field

sam. 2/7

6:58 pm-1:54 pm

1 stop17h 56m

$357

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

mer. 2/4

2:50 pm-10:59 pm

1 stop9h 09m

Idaho Falls Fanning Field

sam. 2/7

9:00 am-1:54 pm

1 stop27h 54m

$368

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 3/9

6:04 pm-10:20 pm

1 stop5h 16m

Idaho Falls Fanning Field

ven. 3/13

6:59 pm-8:52 am

2 stops12h 53m

$393

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 3/9

3:25 pm-10:20 pm

2 stops7h 55m

Idaho Falls Fanning Field

ven. 3/13

6:59 pm-8:52 am

2 stops12h 53m

$425

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

ven. 1/9

8:45 am-1:30 pm

1 stop5h 45m

Idaho Falls Fanning Field

dim. 1/11

2:40 pm-8:58 pm

1 stop5h 18m

$433

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

ven. 1/9

11:20 am-9:16 pm

2 stops10h 56m

Idaho Falls Fanning Field

dim. 1/11

2:40 pm-8:58 pm

1 stop5h 18m

$438

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

lun. 3/9

5:30 am-9:56 am

1 stop5h 26m

Idaho Falls Fanning Field

ven. 3/13

2:35 pm-8:55 pm

1 stop5h 20m

$451

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

mer. 2/4

11:20 am-9:14 pm

2 stops10h 54m

Idaho Falls Fanning Field

sam. 2/7

6:30 am-1:16 pm

1 stop5h 46m

$473

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

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

Prices

Airlines

What is the cheapest day to depart on your flight to Idaho Falls?

Our data shows that Tuesday is the least expensive day to fly to Idaho Falls. Tickets to fly out on this day can be as low as $605. Be sure to avoid booking your departure on a Monday as prices are generally higher than usual. According to our data, the average ticket price to Idaho Falls on Monday is $787.

What is the cheapest time of day to depart on your flight to Idaho Falls?

Our most recent data shows that the best time of day to fly to Idaho Falls is at noon. Flights from St. Louis to Idaho Falls during this time can be as low as $651. Try not to purchase tickets in the afternoon because they tend to be around $685. Of course, these prices can vary depending on the time of year and what airport you fly to.

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 16m
Direct flights	None

The fastest flight from St. Louis to Idaho Falls takes 5h 16m

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 16m 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?
The number of operators available for flights from Lambert-St Louis Airport to Idaho Falls Fanning Field Airport is 2 as of December 2025.
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?
momondo data reveals that the most frequently booked airline on the route from St. Louis to Idaho Falls is United Airlines, representing 71% of all bookings. The subsequent popular airline is Delta at 29%.

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
Delta	PriceFrom $192	Free Cancellation	Rating 7.9 8,005 reviews		Search Delta flights
United Airlines	PriceFrom $400	Free Cancellation	Rating 7.4 9,092 reviews		Search United Airlines flights

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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.