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Cheap flights from Idaho to St. Louis from $112

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 3/8. 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 to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
11:56 am - 1:09 pm
BOI
-
STL
24h 13m
1 stop
Frontier Logo
8:12 pm - 10:20 am
STL
-
BOI
15h 08m
1 stop
$236Frontier
Sun, Mar 1 - Sat, Mar 7
Southwest Logo
2:25 pm - 11:15 pm
GEG
-
STL
6h 50m
1 stop
Southwest Logo
6:35 am - 10:15 am
STL
-
GEG
5h 40m
1 stop
$237Southwest
Wed, Apr 22 - Wed, Apr 29
United Airlines Logo
1:44 pm - 11:21 pm
GEG
-
STL
7h 37m
1 stop
United Airlines Logo
2:50 pm - 9:18 pm
STL
-
GEG
8h 28m
1 stop
$277United Airlines
Wed, Mar 4 - Wed, Mar 11
Frontier Logo
11:56 am - 9:13 pm
BOI
-
STL
32h 17m
2 stops
Frontier Logo
8:12 pm - 10:20 am
STL
-
BOI
15h 08m
1 stop
$279Frontier
Sun, Mar 1 - Sat, Mar 7
United Airlines Logo
12:59 pm - 11:34 pm
BOI
-
STL
9h 35m
2 stops
United Airlines Logo
6:25 am - 12:13 pm
STL
-
BOI
6h 48m
1 stop
$282United Airlines
Tue, Mar 10 - Tue, Mar 17
Delta Logo
11:30 pm - 9:05 am
BOI
-
STL
8h 35m
1 stop
Delta Logo
3:05 pm - 9:09 pm
STL
-
BOI
7h 04m
1 stop
$287Delta
Tue, Mar 10 - Tue, Mar 17
Delta Logo
6:45 am - 2:54 pm
GEG
-
STL
6h 09m
1 stop
Delta Logo
3:05 pm - 9:29 pm
STL
-
GEG
8h 24m
1 stop
$287Delta
Wed, Mar 4 - Tue, Mar 10
Delta Logo
12:48 pm - 11:36 pm
GEG
-
STL
8h 48m
1 stop
Delta Logo
6:00 am - 11:37 am
STL
-
GEG
7h 37m
1 stop
$294Delta
Wed, Mar 4 - Mon, Mar 9
Alaska Airlines Logo
2:22 pm - 11:59 pm
BOI
-
STL
8h 37m
1 stop
Alaska Airlines Logo
5:30 pm - 11:56 pm
STL
-
BOI
7h 26m
1 stop
$348Alaska Airlines
Wed, Mar 25 - Sat, Mar 28
Multiple Airlines Logo
11:53 am - 7:12 pm
BOI
-
STL
6h 19m
1 stop
Multiple Airlines Logo
6:20 pm - 11:58 pm
STL
-
BOI
6h 38m
1 stop
$361Multiple Airlines
Thu, May 14 - Sun, May 17

Southwest flights from Idaho to St. Louis

Our best Southwest deals on Idaho to St. Louis flight tickets
Southwest
Apr 22
GEG2:25 pmSpokane
6h 50m
1 stop
STL11:15 pmLambert-St Louis
Apr 29
STL6:35 amLambert-St Louis
5h 40m
1 stop
GEG10:15 amSpokane
$237
Southwest
Apr 22
GEG5:10 amSpokane
6h 20m
1 stop
STL1:30 pmLambert-St Louis
Apr 29
STL5:35 amLambert-St Louis
9h 30m
2 stops
GEG1:05 pmSpokane
$312
Southwest
Mar 23
GEG2:55 pmSpokane
6h 50m
1 stop
STL11:45 pmLambert-St Louis
Mar 24
STL5:35 pmLambert-St Louis
6h 00m
1 stop
GEG9:35 pmSpokane
$327

Delta flights from Idaho to St. Louis

Our best Delta deals on Idaho to St. Louis flight tickets
Delta
Mar 10
BOI11:30 pmBoise Air Term. Gowen Fld
8h 35m
1 stop
STL9:05 amLambert-St Louis
Mar 17
STL3:05 pmLambert-St Louis
7h 04m
1 stop
BOI9:09 pmBoise Air Term. Gowen Fld
$287
Delta
Mar 4
GEG12:48 pmSpokane
8h 48m
1 stop
STL11:36 pmLambert-St Louis
Mar 9
STL6:00 amLambert-St Louis
7h 37m
1 stop
GEG11:37 amSpokane
$294
Delta
Apr 22
GEG6:00 amSpokane
6h 29m
1 stop
STL2:29 pmLambert-St Louis
Apr 29
STL2:20 pmLambert-St Louis
8h 42m
2 stops
GEG9:02 pmSpokane
$310

momondo Fare Finder

 
Customize your flight search to find flights from Idaho 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 February 13, 2026.
Use the filters below to find and compare flights from Idaho to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Sun 3/1

11:56 am-1:09 pm

1 stop24h 13m

Lambert-St Louis

Sat 3/7

8:12 pm-10:20 am

1 stop15h 08m

$236

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Wed 4/22

2:25 pm-11:15 pm

1 stop6h 50m

Lambert-St Louis

Wed 4/29

6:35 am-10:15 am

1 stop5h 40m

$237

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Wed 3/4

1:44 pm-11:21 pm

1 stop7h 37m

Lambert-St Louis

Wed 3/11

2:50 pm-9:18 pm

1 stop8h 28m

$277

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Sun 3/1

11:56 am-9:13 pm

2 stops32h 17m

Lambert-St Louis

Sat 3/7

8:12 pm-10:20 am

1 stop15h 08m

$279

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Tue 3/10

12:59 pm-11:34 pm

2 stops9h 35m

Lambert-St Louis

Tue 3/17

6:25 am-12:13 pm

1 stop6h 48m

$282

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Tue 3/10

11:30 pm-9:05 am

1 stop8h 35m

Lambert-St Louis

Tue 3/17

3:05 pm-9:09 pm

1 stop7h 04m

$287

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Wed 3/4

6:45 am-2:54 pm

1 stop6h 09m

Lambert-St Louis

Tue 3/10

3:05 pm-9:29 pm

1 stop8h 24m

$287

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

Wed 3/4

12:48 pm-11:36 pm

1 stop8h 48m

Lambert-St Louis

Mon 3/9

6:00 am-11:37 am

1 stop7h 37m

$294

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Wed 3/25

2:22 pm-11:59 pm

1 stop8h 37m

Lambert-St Louis

Sat 3/28

5:30 pm-11:56 pm

1 stop7h 26m

$348

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

Thu 5/14

11:53 am-7:12 pm

1 stop6h 19m

Lambert-St Louis

Sun 5/17

6:20 pm-11:58 pm

1 stop6h 38m

$361

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

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

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

In general, April 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 $292. The month of September is another great option to travel to St. Louis, with average flight prices from Idaho averaging around $294.

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

You could potentially save up to 50% 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

Fastest flight time

4h 26m

Direct flights

None
The fastest flight from Idaho to St. Louis takes 4h 26m
There are no direct flights from Idaho to St. Louis. There are no popular flight routes from Idaho to St. Louis.
Search flight deals

  • 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?

  • 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
DeltaPriceFrom $143Free CancellationRating
7.9
8,192 reviews
Search Delta flights
American AirlinesPriceFrom $226Free CancellationRating
7.2
11,276 reviews
Search American Airlines flights
Alaska AirlinesPriceFrom $278Free CancellationRating
8.0
11,878 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $286Free CancellationRating
8.0
4,283 reviews
Search Southwest flights
United AirlinesPriceFrom $286Free CancellationRating
7.4
9,286 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
St. Peters
Fenton
Wentzville
Alton
Farmington
Clayton
Edwardsville
Eureka
Festus
Litchfield
Glencoe
Shrewsbury

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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