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

United Airlines, American Airlines, and Southwest 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 41% 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 April 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.

$155 Cheap Flights from St. Louis to Idaho in 2026

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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.

8:08 pm - 12:09 pm

STL

BOI

17h 01m

1 stop

1:04 pm - 7:23 pm

BOI

STL

5h 19m

1 stop

$241Frontier

Wed, Jun 24 - Tue, Jun 30

7:00 am - 3:33 pm

STL

BOI

9h 33m

1 stop

2:57 pm - 11:59 pm

BOI

STL

8h 02m

1 stop

$317Alaska Airlines

Sat, May 2 - Tue, May 5

7:05 am - 12:32 pm

STL

GEG

7h 27m

1 stop

1:13 pm - 11:56 pm

GEG

STL

8h 43m

1 stop

$347American Airlines

Wed, May 6 - Wed, May 13

7:05 am - 12:32 pm

STL

GEG

7h 27m

1 stop

6:00 am - 5:21 pm

GEG

STL

9h 21m

1 stop

$352American Airlines

Thu, Apr 30 - Sat, May 2

6:45 pm - 10:40 pm

STL

IDA

4h 55m

1 stop

6:58 pm - 8:30 am

IDA

STL

12h 32m

2 stops

$354Delta

Tue, Apr 14 - Sat, Apr 18

6:30 am - 3:18 pm

STL

GEG

10h 48m

2 stops

1:41 pm - 8:57 pm

GEG

STL

5h 16m

1 stop

$357United Airlines

Sat, May 2 - Sat, May 30

8:54 am - 3:24 pm

STL

JAC

7h 30m

1 stop

2:35 pm - 8:54 pm

JAC

STL

5h 19m

1 stop

$359United Airlines

Sat, Apr 18 - Wed, Apr 22

6:45 pm - 11:57 pm

STL

BOI

6h 12m

1 stop

2:18 pm - 11:35 pm

BOI

STL

8h 17m

1 stop

$361Delta

Mon, Apr 27 - Wed, May 6

5:15 pm - 12:45 am

STL

BOI

8h 30m

2 stops

4:05 pm - 11:15 pm

BOI

STL

6h 10m

1 stop

$366Southwest

Mon, Apr 27 - Wed, May 6

6:55 pm - 12:25 am

STL

BOI

6h 30m

1 stop

4:05 pm - 11:55 pm

BOI

STL

6h 50m

1 stop

$383Southwest

Tue, Jun 23 - Wed, Jun 24

Southwest flights from St. Louis to Idaho

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

Southwest

Apr 27

STL5:15 pmLambert-St Louis

8h 30m

2 stops

BOI12:45 amBoise Air Term. Gowen Fld

May 6

BOI4:05 pmBoise Air Term. Gowen Fld

6h 10m

1 stop

STL11:15 pmLambert-St Louis

$366

Southwest

Jun 23

STL6:55 pmLambert-St Louis

6h 30m

1 stop

BOI12:25 amBoise Air Term. Gowen Fld

Jun 24

BOI4:05 pmBoise Air Term. Gowen Fld

6h 50m

1 stop

STL11:55 pmLambert-St Louis

$383

Southwest

Jun 23

STL5:20 pmLambert-St Louis

8h 05m

2 stops

BOI12:25 amBoise Air Term. Gowen Fld

Jun 24

BOI4:05 pmBoise Air Term. Gowen Fld

6h 50m

1 stop

STL11:55 pmLambert-St Louis

$388

Delta flights from St. Louis to Idaho

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

Delta

Apr 14

STL6:45 pmLambert-St Louis

4h 55m

1 stop

IDA10:40 pmIdaho Falls Fanning Field

Apr 18

IDA6:58 pmIdaho Falls Fanning Field

12h 32m

2 stops

STL8:30 amLambert-St Louis

$354

Delta

Apr 27

STL6:45 pmLambert-St Louis

6h 12m

1 stop

BOI11:57 pmBoise Air Term. Gowen Fld

May 6

BOI2:18 pmBoise Air Term. Gowen Fld

8h 17m

1 stop

STL11:35 pmLambert-St Louis

$361

Delta

May 25

STL6:45 amLambert-St Louis

11h 14m

2 stops

JAC4:59 pmJackson Hole

Jun 2

JAC1:15 pmJackson Hole

9h 06m

2 stops

STL11:21 pmLambert-St Louis

$369

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Wed 6/24

8:08 pm-12:09 pm

1 stop17h 01m

Boise Air Term. Gowen Fld

Tue 6/30

1:04 pm-7:23 pm

1 stop5h 19m

$241

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Sat 5/2

7:00 am-3:33 pm

1 stop9h 33m

Boise Air Term. Gowen Fld

Tue 5/5

2:57 pm-11:59 pm

1 stop8h 02m

$317

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Wed 5/6

7:05 am-12:32 pm

1 stop7h 27m

Spokane

Wed 5/13

1:13 pm-11:56 pm

1 stop8h 43m

$347

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Thu 4/30

7:05 am-12:32 pm

1 stop7h 27m

Spokane

Sat 5/2

6:00 am-5:21 pm

1 stop9h 21m

$352

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Tue 4/14

6:45 pm-10:40 pm

1 stop4h 55m

Idaho Falls Fanning Field

Sat 4/18

6:58 pm-8:30 am

2 stops12h 32m

$354

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Sat 5/2

6:30 am-3:18 pm

2 stops10h 48m

Spokane

Sat 5/30

1:41 pm-8:57 pm

1 stop5h 16m

$357

Quickest round-trip

St. LouisJackson

STL - JAC

STLJAC

Lambert-St Louis

Sat 4/18

8:54 am-3:24 pm

1 stop7h 30m

Jackson Hole

Wed 4/22

2:35 pm-8:54 pm

1 stop5h 19m

$359

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Mon 4/27

6:45 pm-11:57 pm

1 stop6h 12m

Boise Air Term. Gowen Fld

Wed 5/6

2:18 pm-11:35 pm

1 stop8h 17m

$361

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Mon 4/27

5:15 pm-12:45 am

2 stops8h 30m

Boise Air Term. Gowen Fld

Wed 5/6

4:05 pm-11:15 pm

1 stop6h 10m

$366

St. LouisBoise

STL - BOI

STLBOI

Lambert-St Louis

Tue 6/23

6:55 pm-12:25 am

1 stop6h 30m

Boise Air Term. Gowen Fld

Wed 6/24

4:05 pm-11:55 pm

1 stop6h 50m

$383

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 November to fly from St. Louis, when ticket prices are also cheap, with an average price of $373.

How far in advance should I book a flight to Idaho?

You are more likely to see cheaper flights to Idaho from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Idaho for around $435 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Idaho from St. Louis for as low as $292 on momondo.

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

Fastest flight time	4h 55m
Direct flights	None

The fastest flight from St. Louis to Idaho takes 4h 55m

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 April 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
Delta	PriceFrom $163	Free Cancellation	Rating 7.9 8,386 reviews	Search Delta flights
American Airlines	PriceFrom $186	Free Cancellation	Rating 7.1 11,559 reviews	Search American Airlines flights
United Airlines	PriceFrom $290	Free Cancellation	Rating 7.4 9,542 reviews	Search United Airlines flights
Southwest	PriceFrom $296	Free Cancellation	Rating 8.0 4,343 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.