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

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

What airlines fly to St. Louis?

United Airlines, Delta and American Airlines are the top three most popular airlines that fly to St. Louis from Idaho according to our data. United Airlines is the first choice among our users, with 45% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 4 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

How long does it take to fly to St. Louis?

Flight times from Idaho to St. Louis vary, but if you’re flying out of Idaho Falls and flying into St. Louis (one of the most popular routes), then the duration is 4h 48m on average. Another popular route from Idaho to St. Louis is flying from Boise to St. Louis, which will take roughly 5h 23m. Keep in mind that layovers or delays could extend your travel time.

How many flights depart from Idaho to St. Louis on average per week?

The number of flights available between Idaho and St. Louis is 3 per week as of October 2026. The most frequent departure day is Mon, with 33% of weekly flights leaving on this day.

When did momondo last update prices for flights from Idaho to Lambert-St Louis Airport?

Prices for flights from Idaho to Lambert-St Louis Airport are refreshed on a daily basis.

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

As of October 2026, there are 4 operators available to choose from for flights from Idaho to Lambert-St Louis Airport.

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

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Idaho to Lambert-St Louis Airport.

What documentation or ID do you need to fly to Lambert-St Louis Airport?

The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$154 Cheap Flights from Idaho to St. Louis in 2026/27

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Find the cheapest flights from Idaho to St. Louis

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1:15 pm - 9:41 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

7h 26m1 stop Salt Lake City

7:30 am - 12:17 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

5h 47m1 stop Salt Lake City

$241Delta

Thu, Jan 21 - Thu, Jan 28

7:10 am - 4:30 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

8h 20m2 stops Phoenix Sky Harbor Intl Denver Intl

8:35 am - 4:05 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

8h 30m1 stop Denver Intl

$277Southwest

Thu, Jan 21 - Thu, Jan 28

9:51 pm - 1:47 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

14h 56m1 stop Las Vegas Harry Reid Intl

2:47 pm - 8:56 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

7h 09m1 stop Las Vegas Harry Reid Intl

$296Frontier

Thu, Dec 3 - Fri, Dec 11

10:38 am - 11:18 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

11h 40m2 stops Seattle/Tacoma Intl Minneapolis St Paul

2:15 pm - 11:52 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

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

$313Delta

Thu, Jan 21 - Thu, Jan 28

5:45 am - 12:30 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

5h 45m1 stop Phoenix Sky Harbor Intl

8:25 am - 2:15 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

6h 50m1 stop San Diego

$360Southwest

Thu, Dec 3 - Thu, Dec 10

2:41 pm - 9:59 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

6h 18m1 stop Dallas/Fort Worth

6:00 am - 1:51 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

8h 51m1 stop Dallas/Fort Worth

$369American Airlines

Tue, Nov 10 - Thu, Nov 12

1:24 pm - 10:15 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

7h 51m1 stop Chicago O'Hare Intl

6:00 am - 1:51 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

8h 51m1 stop Dallas/Fort Worth

$369American Airlines

Mon, Nov 16 - Wed, Nov 18

3:01 pm - 2:56 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

22h 55m1 stop Seattle/Tacoma Intl

3:04 pm - 10:20 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

8h 16m1 stop Seattle/Tacoma Intl

$414Alaska Airlines

Tue, Feb 9 - Thu, Feb 11

12:31 pm - 9:40 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

8h 09m1 stop Chicago O'Hare Intl

8:00 am - 4:42 pmSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

9h 42m1 stop San Francisco

$425United Airlines

Wed, Oct 28 - Thu, Oct 29

12:00 pm - 11:24 pmBOI Boise Air Term. Gowen Fld-STL Lambert-St Louis

10h 24m2 stops San Francisco Chicago O'Hare Intl

5:00 am - 11:31 amSTL Lambert-St Louis-BOI Boise Air Term. Gowen Fld

7h 31m1 stop Chicago O'Hare Intl

$430United Airlines

Wed, Oct 28 - Thu, Oct 29

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Delta flights from Idaho to St. Louis

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

Delta

Jan 21

BOI1:15 pmBoise Air Term. Gowen Fld

7h 26m

1 stop

STL9:41 pmLambert-St Louis

Jan 28

STL7:30 amLambert-St Louis

5h 47m

1 stop

BOI12:17 pmBoise Air Term. Gowen Fld

$241

Delta

Jan 21

BOI10:38 amBoise Air Term. Gowen Fld

11h 40m

2 stops

STL11:18 pmLambert-St Louis

Jan 28

STL2:15 pmLambert-St Louis

10h 37m

2 stops

BOI11:52 pmBoise Air Term. Gowen Fld

$313

Delta

Dec 24

IDA1:09 pmIdaho Falls Fanning Field

6h 57m

1 stop

STL9:06 pmLambert-St Louis

Dec 28

STL6:20 amLambert-St Louis

12h 53m

2 stops

IDA6:13 pmIdaho Falls Fanning Field

$354

Southwest flights from Idaho to St. Louis

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

Southwest

Jan 21

BOI7:10 amBoise Air Term. Gowen Fld

8h 20m

2 stops

STL4:30 pmLambert-St Louis

Jan 28

STL8:35 amLambert-St Louis

8h 30m

1 stop

BOI4:05 pmBoise Air Term. Gowen Fld

$277

Southwest

Dec 3

BOI5:45 amBoise Air Term. Gowen Fld

5h 45m

1 stop

STL12:30 pmLambert-St Louis

Dec 10

STL8:25 amLambert-St Louis

6h 50m

1 stop

BOI2:15 pmBoise Air Term. Gowen Fld

$360

Southwest

Dec 3

BOI5:45 amBoise Air Term. Gowen Fld

5h 45m

1 stop

STL12:30 pmLambert-St Louis

Dec 10

STL6:25 amLambert-St Louis

8h 50m

2 stops

BOI2:15 pmBoise Air Term. Gowen Fld

$370

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Thu 1/21

1:15 pm-9:41 pm

1 stop7h 26m

Lambert-St Louis

Thu 1/28

7:30 am-12:17 pm

1 stop5h 47m

$241

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Thu 1/21

7:10 am-4:30 pm

2 stops8h 20m

Lambert-St Louis

Thu 1/28

8:35 am-4:05 pm

1 stop8h 30m

$277

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Thu 12/3

9:51 pm-1:47 pm

1 stop14h 56m

Lambert-St Louis

Fri 12/11

2:47 pm-8:56 pm

1 stop7h 09m

$296

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Thu 1/21

10:38 am-11:18 pm

2 stops11h 40m

Lambert-St Louis

Thu 1/28

2:15 pm-11:52 pm

2 stops10h 37m

$313

Quickest round-trip

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Thu 12/3

5:45 am-12:30 pm

1 stop5h 45m

Lambert-St Louis

Thu 12/10

8:25 am-2:15 pm

1 stop6h 50m

$360

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Tue 11/10

2:41 pm-9:59 pm

1 stop6h 18m

Lambert-St Louis

Thu 11/12

6:00 am-1:51 pm

1 stop8h 51m

$369

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Mon 11/16

1:24 pm-10:15 pm

1 stop7h 51m

Lambert-St Louis

Wed 11/18

6:00 am-1:51 pm

1 stop8h 51m

$369

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Tue 2/9

3:01 pm-2:56 pm

1 stop22h 55m

Lambert-St Louis

Thu 2/11

3:04 pm-10:20 pm

1 stop8h 16m

$414

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Wed 10/28

12:31 pm-9:40 pm

1 stop8h 09m

Lambert-St Louis

Thu 10/29

8:00 am-4:42 pm

1 stop9h 42m

$425

BoiseSt. Louis

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

BOISTL

Boise Air Term. Gowen Fld

Wed 10/28

12:00 pm-11:24 pm

2 stops10h 24m

Lambert-St Louis

Thu 10/29

5:00 am-11:31 am

1 stop7h 31m

$430

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 Idaho 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

Prices

Airlines

Other information

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

In general, January is the cheapest month to fly from Idaho to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $440. The month of May is another great option to travel to St. Louis, with average flight prices from Idaho averaging around $443.

Can stopping save me money on Idaho to St. Louis flights?

You could potentially save up to 60% on your flight if you consider stops on a Idaho to St. Louis flight.

Cheap Idaho to St. Louis flight deals and tips

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

Best Price Found	$154
Fastest flight time	4h 48m
Direct flights	None

The best one-way flight to St. Louis from Idaho in the past 72 hours is $154. The best round-trip flight deal from Idaho to St. Louis found on momondo in the last 72 hours is $241.

The fastest flight from Idaho to St. Louis takes 4h 48m

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

Search flight deals

Frequently asked questions about flying from Idaho to St. Louis

When did momondo last update prices for flights from Idaho to Lambert-St Louis Airport?
Prices for flights from Idaho to Lambert-St Louis Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Idaho to Lambert-St Louis Airport?
As of October 2026, there are 4 operators available to choose from for flights from Idaho to Lambert-St Louis Airport.
How old do you have to be to fly from Idaho to Lambert-St Louis Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Idaho to Lambert-St Louis Airport.
What documentation or ID do you need to fly to Lambert-St Louis Airport?
The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

Best airlines flying from Idaho to St. Louis

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

Airline	Rating	Free Cancellation	Price
Delta	PriceFrom $164	Free Cancellation	Rating 7.8 8,649 reviews	Search Delta flights
American Airlines	PriceFrom $328	Free Cancellation	Rating 7.0 12,162 reviews	Search American Airlines flights
Southwest	PriceFrom $347	Free Cancellation	Rating 7.9 4,216 reviews	Search Southwest flights
United Airlines	PriceFrom $355	Free Cancellation	Rating 7.4 10,351 reviews	Search United Airlines flights

St. Charles

Fairview Heights

Chesterfield

Maryland Heights

St. Peters

Alton

Florissant

Collinsville

Farmington

Hermann

Clayton

Festus

Fenton

O'Fallon

Edwardsville

Eureka

Wentzville

Litchfield

Grafton

Waterloo

Why use momondo?

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Idaho to St. Louis for you.

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

Yes. momondo enables you to select and highlight flights to St. Louis from Idaho with this policy.

How can momondo help me find flights from Idaho to St. Louis?

Once you have performed a search for Idaho to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

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

If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Idaho and alert you when they change.

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Cheap flights from Idaho to St. Louis from $154

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 to St. Louis departing on 11/12. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Delta flights from Idaho to St. Louis

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

Southwest flights from Idaho to St. Louis

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

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

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

Can stopping save me money on Idaho to St. Louis flights?

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

What airlines fly to St. Louis?

How many flights depart from Idaho to St. Louis on average per week?

How long does it take to fly to St. Louis?

Cheap Idaho to St. Louis flight deals and tips

Best Price Found

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Direct flights

Frequently asked questions about flying from Idaho to St. Louis

Best airlines flying from Idaho to St. Louis

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

Traveling to a place near St. Louis?

Why use momondo?

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

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Find better results for your trip to the United States

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Airlines are sorted and displayed according to clicks in the past 7 days on momondo

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List of cabin classes available on flights landing in St. Louis. Availability may vary depending on flight origin and airline.

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