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

American Airlines, United Airlines, and Delta are the most popular carriers operating from Lambert-St Louis to Idaho

What airlines fly to Idaho?

United Airlines, Delta and Southwest are the top three most popular airlines that fly to Idaho from St. Louis according to our data. United Airlines is the first choice among our users, with 51% of people opting to fly with this airline when traveling to Idaho. Keep in mind that there are 4 different airlines that fly to Idaho 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?

Prices for flights from Lambert-St Louis Airport to Idaho refresh daily.

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

There are 5 operators available for flights from Lambert-St Louis Airport to Idaho as of September 2026.

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

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.

What documentation or ID do you need to fly to Idaho?

The travel and health documents you'll need for your trip to Idaho may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Idaho. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

$165 Cheap Flights from St. Louis to Idaho in 2026

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from St. Louis to Idaho

Round-trip

One-way

Last minute

Cheap round-trip flights

Enter your travel dates to find the best prices.

2:22 pm - 10:08 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

8h 46m2 stops Salt Lake City Seattle/Tacoma Intl

12:08 pm - 11:21 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

10h 13m2 stops Seattle/Tacoma Intl Minneapolis St Paul

$313Delta

Wed, Oct 21 - Wed, Oct 28

2:22 pm - 11:59 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

10h 37m2 stops Salt Lake City Seattle/Tacoma Intl

6:45 am - 4:43 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

8h 58m2 stops Seattle/Tacoma Intl Minneapolis St Paul

$318Delta

Fri, Oct 23 - Tue, Oct 27

12:27 pm - 1:55 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

26h 28m1 stop Las Vegas Harry Reid Intl

2:50 pm - 11:17 amBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

19h 27m1 stop Las Vegas Harry Reid Intl

$328Frontier

Thu, Sep 24 - Sun, Sep 27

12:27 pm - 1:55 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

26h 28m1 stop Las Vegas Harry Reid Intl

2:50 pm - 11:32 amBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

19h 42m1 stop Las Vegas Harry Reid Intl

$340Frontier

Thu, Sep 24 - Mon, Sep 28

5:10 am - 9:53 amSTL Lambert-St Louis-IDA Idaho Falls Fanning Field

5h 43m1 stop Denver Intl

4:05 pm - 11:44 pmIDA Idaho Falls Fanning Field-STL Lambert-St Louis

6h 39m1 stop Denver Intl

$349United Airlines

Thu, Oct 1 - Sat, Oct 3

5:10 am - 9:53 amSTL Lambert-St Louis-IDA Idaho Falls Fanning Field

5h 43m1 stop Denver Intl

5:51 pm - 11:44 pmIDA Idaho Falls Fanning Field-STL Lambert-St Louis

4h 53m1 stop Denver Intl

$349United Airlines

Mon, Oct 5 - Tue, Oct 6

6:00 am - 1:05 pmSTL Lambert-St Louis-IDA Idaho Falls Fanning Field

8h 05m1 stop Dallas/Fort Worth

1:35 pm - 9:59 pmIDA Idaho Falls Fanning Field-STL Lambert-St Louis

7h 24m1 stop Dallas/Fort Worth

$349American Airlines

Thu, Dec 10 - Sat, Dec 12

6:00 am - 4:59 pmSTL Lambert-St Louis-IDA Idaho Falls Fanning Field

11h 59m2 stops Dallas/Fort Worth Phoenix Sky Harbor Intl

6:36 am - 1:43 pmIDA Idaho Falls Fanning Field-STL Lambert-St Louis

6h 07m1 stop Phoenix Sky Harbor Intl

$354American Airlines

Thu, Dec 10 - Sat, Dec 12

6:02 am - 12:54 pmSTL Lambert-St Louis-GEG Spokane

8h 52m1 stop Seattle/Tacoma Intl

1:38 pm - 11:59 pmGEG Spokane-STL Lambert-St Louis

8h 21m1 stop Seattle/Tacoma Intl

$369Alaska Airlines

Sat, Oct 24 - Tue, Oct 27

6:02 am - 11:39 amSTL Lambert-St Louis-GEG Spokane

7h 37m1 stop Seattle/Tacoma Intl

1:38 pm - 11:59 pmGEG Spokane-STL Lambert-St Louis

8h 21m1 stop Seattle/Tacoma Intl

$379Alaska Airlines

Sat, Oct 24 - Tue, Oct 27

Cheap last minute flights

Enter your travel dates to find the best prices.

12:17 pm - 1:55 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

26h 38m1 stop Las Vegas Harry Reid Intl

2:50 pm - 11:32 amBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

19h 42m1 stop Las Vegas Harry Reid Intl

$370Frontier

Sat, Sep 12 - Mon, Sep 14

9:00 am - 4:06 pmSTL Lambert-St Louis-WYS West Yellowstone

8h 06m1 stop Denver Intl

1:55 pm - 8:38 pmWYS West Yellowstone-STL Lambert-St Louis

5h 43m1 stop Denver Intl

$524United Airlines

Sat, Sep 12 - Mon, Sep 14

9:00 am - 4:06 pmSTL Lambert-St Louis-WYS West Yellowstone

8h 06m1 stop Denver Intl

1:55 pm - 10:59 pmWYS West Yellowstone-STL Lambert-St Louis

8h 04m2 stops Denver Intl Chicago O'Hare Intl

$530United Airlines

Sat, Sep 12 - Mon, Sep 14

5:00 am - 12:07 pmSTL Lambert-St Louis-JAC Jackson Hole

8h 07m1 stop Chicago O'Hare Intl

4:11 pm - 11:43 pmJAC Jackson Hole-STL Lambert-St Louis

6h 32m1 stop Dallas/Fort Worth

$567American Airlines

Wed, Sep 16 - Mon, Sep 21

5:00 am - 3:01 pmSTL Lambert-St Louis-JAC Jackson Hole

11h 01m2 stops Chicago O'Hare Intl Dallas/Fort Worth

4:11 pm - 11:43 pmJAC Jackson Hole-STL Lambert-St Louis

6h 32m1 stop Dallas/Fort Worth

$572American Airlines

Wed, Sep 16 - Mon, Sep 21

8:00 am - 12:08 pmSTL Lambert-St Louis-JAC Jackson Hole

5h 08m1 stop Salt Lake City

5:55 pm - 12:44 amJAC Jackson Hole-STL Lambert-St Louis

5h 49m1 stop Salt Lake City

$595Delta

Wed, Sep 16 - Mon, Sep 21

6:08 pm - 11:55 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

6h 47m1 stop Portland

6:23 am - 2:21 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

6h 58m1 stop Seattle/Tacoma Intl

$613Alaska Airlines

Wed, Sep 16 - Tue, Sep 22

2:25 pm - 7:21 pmSTL Lambert-St Louis-JAC Jackson Hole

5h 56m1 stop Salt Lake City

5:55 pm - 12:44 amJAC Jackson Hole-STL Lambert-St Louis

5h 49m1 stop Salt Lake City

$615Delta

Wed, Sep 16 - Mon, Sep 21

6:29 am - 11:53 pmSTL Lambert-St Louis-GEG Spokane

19h 24m2 stops Seattle/Tacoma Intl San Diego

8:31 am - 6:38 pmGEG Spokane-STL Lambert-St Louis

8h 07m1 stop Seattle/Tacoma Intl

$717Alaska Airlines

Sat, Sep 12 - Sat, Sep 26

8:10 pm - 9:19 amSTL Lambert-St Louis-GEG Spokane

15h 09m2 stops Denver Intl Las Vegas Harry Reid Intl

10:09 am - 11:17 amGEG Spokane-STL Lambert-St Louis

23h 08m1 stop Las Vegas Harry Reid Intl

$748Multiple Airlines

Wed, Sep 16 - Sun, Sep 20

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Frontier flights from St. Louis to Idaho

Our best Frontier deals on St. Louis to Idaho flight tickets

Frontier

Sep 24

STL12:27 pmLambert-St Louis

26h 28m

1 stop

BOI1:55 pmBoise Air Term. Gowen Fld

Sep 27

BOI2:50 pmBoise Air Term. Gowen Fld

19h 27m

1 stop

STL11:17 amLambert-St Louis

$328

Frontier

Sep 24

STL12:27 pmLambert-St Louis

26h 28m

1 stop

BOI1:55 pmBoise Air Term. Gowen Fld

Sep 28

BOI2:50 pmBoise Air Term. Gowen Fld

19h 42m

1 stop

STL11:32 amLambert-St Louis

$340

Frontier

Sep 27

STL12:27 pmLambert-St Louis

26h 28m

1 stop

BOI1:55 pmBoise Air Term. Gowen Fld

Oct 4

BOI2:50 pmBoise Air Term. Gowen Fld

19h 27m

1 stop

STL11:17 amLambert-St Louis

$363

United Airlines flights from St. Louis to Idaho

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

United Airlines

Oct 1

STL5:10 amLambert-St Louis

5h 43m

1 stop

IDA9:53 amIdaho Falls Fanning Field

Oct 3

IDA4:05 pmIdaho Falls Fanning Field

6h 39m

1 stop

STL11:44 pmLambert-St Louis

$349

United Airlines

Oct 6

STL7:08 amLambert-St Louis

6h 50m

1 stop

BOI12:58 pmBoise Air Term. Gowen Fld

Oct 6

BOI5:30 pmBoise Air Term. Gowen Fld

5h 14m

1 stop

STL11:44 pmLambert-St Louis

$364

United Airlines

Oct 6

STL5:10 amLambert-St Louis

8h 48m

2 stops

BOI12:58 pmBoise Air Term. Gowen Fld

Oct 6

BOI5:30 pmBoise Air Term. Gowen Fld

5h 14m

1 stop

STL11:44 pmLambert-St Louis

$374

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisBoise

STL Lambert-St Louis - BOI Boise Air Term. Gowen Fld

STLBOI

Lambert-St Louis

Wed 10/21

2:22 pm-10:08 pm

2 stops8h 46m

Boise Air Term. Gowen Fld

Wed 10/28

12:08 pm-11:21 pm

2 stops10h 13m

$313

St. LouisBoise

STL Lambert-St Louis - BOI Boise Air Term. Gowen Fld

STLBOI

Lambert-St Louis

Fri 10/23

2:22 pm-11:59 pm

2 stops10h 37m

Boise Air Term. Gowen Fld

Tue 10/27

6:45 am-4:43 pm

2 stops8h 58m

$318

St. LouisBoise

STL Lambert-St Louis - BOI Boise Air Term. Gowen Fld

STLBOI

Lambert-St Louis

Thu 9/24

12:27 pm-1:55 pm

1 stop26h 28m

Boise Air Term. Gowen Fld

Sun 9/27

2:50 pm-11:17 am

1 stop19h 27m

$328

St. LouisBoise

STL Lambert-St Louis - BOI Boise Air Term. Gowen Fld

STLBOI

Lambert-St Louis

Thu 9/24

12:27 pm-1:55 pm

1 stop26h 28m

Boise Air Term. Gowen Fld

Mon 9/28

2:50 pm-11:32 am

1 stop19h 42m

$340

St. LouisIdaho Falls

STL Lambert-St Louis - IDA Idaho Falls Fanning Field

STLIDA

Lambert-St Louis

Thu 10/1

5:10 am-9:53 am

1 stop5h 43m

Idaho Falls Fanning Field

Sat 10/3

4:05 pm-11:44 pm

1 stop6h 39m

$349

Quickest round-trip

St. LouisIdaho Falls

STL Lambert-St Louis - IDA Idaho Falls Fanning Field

STLIDA

Lambert-St Louis

Mon 10/5

5:10 am-9:53 am

1 stop5h 43m

Idaho Falls Fanning Field

Tue 10/6

5:51 pm-11:44 pm

1 stop4h 53m

$349

St. LouisIdaho Falls

STL Lambert-St Louis - IDA Idaho Falls Fanning Field

STLIDA

Lambert-St Louis

Thu 12/10

6:00 am-1:05 pm

1 stop8h 05m

Idaho Falls Fanning Field

Sat 12/12

1:35 pm-9:59 pm

1 stop7h 24m

$349

St. LouisIdaho Falls

STL Lambert-St Louis - IDA Idaho Falls Fanning Field

STLIDA

Lambert-St Louis

Thu 12/10

6:00 am-4:59 pm

2 stops11h 59m

Idaho Falls Fanning Field

Sat 12/12

6:36 am-1:43 pm

1 stop6h 07m

$354

St. LouisSpokane

STL Lambert-St Louis - GEG Spokane

STLGEG

Lambert-St Louis

Sat 10/24

6:02 am-12:54 pm

1 stop8h 52m

Spokane

Tue 10/27

1:38 pm-11:59 pm

1 stop8h 21m

$369

St. LouisSpokane

STL Lambert-St Louis - GEG Spokane

STLGEG

Lambert-St Louis

Sat 10/24

6:02 am-11:39 am

1 stop7h 37m

Spokane

Tue 10/27

1:38 pm-11:59 pm

1 stop8h 21m

$379

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

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 month to fly to Idaho?

In general, January is the cheapest month to fly from St. Louis to Idaho. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $359. If you don’t want to visit Idaho in January, then you should wait until October to fly from St. Louis, when ticket prices are also cheap, with an average price of $411.

Cheap St. Louis to Idaho flight deals and tips

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

Best Price Found	$165
Fastest flight time	5h 13m
Direct flights	None

The best one-way flight to Idaho from St. Louis in the past 72 hours is $165. The best round-trip flight deal from St. Louis to Idaho found on momondo in the last 72 hours is $313.

The fastest flight from St. Louis to Idaho takes 5h 13m

There are no direct flights from St. Louis to Idaho. There are no popular flight routes from St. Louis to Idaho.

Search flight deals

Frequently asked questions about flying from St. Louis to Idaho

When did momondo last update prices for flights from Lambert-St Louis Airport to Idaho?
Prices for flights from Lambert-St Louis Airport to Idaho refresh daily.
How many operators does momondo search for flights from Lambert-St Louis Airport to Idaho?
There are 5 operators available for flights from Lambert-St Louis Airport to Idaho as of September 2026.
How old do you have to be to fly from Lambert-St Louis Airport to Idaho?
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.
What documentation or ID do you need to fly to Idaho?
The travel and health documents you'll need for your trip to Idaho may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Idaho. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Best airlines flying from St. Louis to Idaho

Compare and see reviews for airlines that fly from St. Louis to Idaho with momondo

Airline	Rating	Free Cancellation	Price
American Airlines	PriceFrom $207	Free Cancellation	Rating 7.1 12,045 reviews	Search American Airlines flights
Delta	PriceFrom $240	Free Cancellation	Rating 7.8 8,554 reviews	Search Delta flights
United Airlines	PriceFrom $290	Free Cancellation	Rating 7.4 10,194 reviews	Search United Airlines flights
Southwest	PriceFrom $336	Free Cancellation	Rating 8.0 4,195 reviews	Search Southwest flights

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Idaho from St. Louis.

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

momondo does allow users to show only those flights to Idaho 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?

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.

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

Yes momondo offers price alerts on flights to Idaho from St. Louis. 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.