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Cheap flights from Idaho to St. Louis from $243

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 3/12. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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.
Delta Logo
10:41 am - 9:38 pm
BOI
-
STL
9h 57m2 stops
Delta Logo
2:22 pm - 9:56 pm
STL
-
BOI
8h 34m2 stops
$256Delta
sáb., feb. 28 - mié., mar. 4
Delta Logo
1:25 pm - 11:23 pm
GEG
-
STL
7h 58m2 stops
Delta Logo
3:05 pm - 10:33 pm
STL
-
GEG
9h 28m2 stops
$256Delta
jue., mar. 5 - lun., mar. 9
United Airlines Logo
2:31 pm - 8:58 pm
SUN
-
STL
5h 27m1 stop
United Airlines Logo
4:15 pm - 9:29 pm
STL
-
SUN
6h 14m1 stop
$269United Airlines
sáb., ene. 24 - sáb., ene. 31
United Airlines Logo
8:00 am - 8:58 pm
SUN
-
STL
11h 58m2 stops
United Airlines Logo
1:15 pm - 9:29 pm
STL
-
SUN
9h 14m2 stops
$279United Airlines
sáb., ene. 24 - sáb., ene. 31
American Airlines Logo
6:00 am - 4:14 pm
GEG
-
STL
8h 14m1 stop
American Airlines Logo
11:55 am - 6:49 pm
STL
-
GEG
8h 54m1 stop
$290American Airlines
mar., ene. 20 - lun., feb. 2
Multiple Airlines Logo
8:58 pm - 8:50 pm
GEG
-
STL
21h 52m1 stop
Multiple Airlines Logo
6:41 pm - 2:16 pm
STL
-
GEG
21h 35m2 stops
$294Multiple Airlines
dom., feb. 8 - sáb., feb. 21
Alaska Airlines Logo
6:28 am - 1:51 pm
BOI
-
STL
6h 23m1 stop
Alaska Airlines Logo
7:00 am - 2:58 pm
STL
-
BOI
8h 58m1 stop
$295Alaska Airlines
sáb., feb. 28 - mié., mar. 4
Multiple Airlines Logo
8:58 pm - 8:50 pm
GEG
-
STL
21h 52m1 stop
Multiple Airlines Logo
2:51 pm - 2:16 pm
STL
-
GEG
25h 25m1 stop
$306Multiple Airlines
dom., feb. 8 - sáb., feb. 21
American Airlines Logo
6:13 am - 1:53 pm
BOI
-
STL
6h 40m1 stop
American Airlines Logo
6:00 am - 1:08 pm
STL
-
BOI
8h 08m1 stop
$326American Airlines
jue., ene. 29 - lun., feb. 2
Alaska Airlines Logo
5:45 am - 1:54 pm
GEG
-
STL
6h 09m1 stop
Alaska Airlines Logo
2:50 pm - 12:44 pm
STL
-
GEG
23h 54m1 stop
$327Alaska Airlines
mié., ene. 28 - dom., feb. 1

Delta flights from Idaho to St. Louis

Our best Delta deals on Idaho to St. Louis flight tickets
Delta
Feb 28
BOI10:41 amBoise Air Term. Gowen Fld
9h 57m
2 stops
STL9:38 pmLambert-St Louis
Mar 4
STL2:22 pmLambert-St Louis
8h 34m
2 stops
BOI9:56 pmBoise Air Term. Gowen Fld
$256
Find similar
Delta
Jan 24
SUN12:55 pmHailey Sun Valley-Friedman
9h 41m
2 stops
STL11:36 pmLambert-St Louis
Jan 31
STL2:38 pmLambert-St Louis
8h 17m
1 stop
SUN9:55 pmHailey Sun Valley-Friedman
$274
Find similar
Delta
Jan 30
GEG7:25 pmSpokane
12h 14m
2 stops
STL9:39 amLambert-St Louis
Feb 8
STL3:31 pmLambert-St Louis
9h 17m
2 stops
GEG10:48 pmSpokane
$277
Find similar

Alaska Airlines flights from Idaho to St. Louis

Our best Alaska Airlines deals on Idaho to St. Louis flight tickets
Alaska Airlines
Feb 28
BOI6:28 amBoise Air Term. Gowen Fld
6h 23m
1 stop
STL1:51 pmLambert-St Louis
Mar 4
STL7:00 amLambert-St Louis
8h 58m
1 stop
BOI2:58 pmBoise Air Term. Gowen Fld
$295
Find similar
Alaska Airlines
Jan 28
GEG5:45 amSpokane
6h 09m
1 stop
STL1:54 pmLambert-St Louis
Feb 1
STL2:50 pmLambert-St Louis
23h 54m
1 stop
GEG12:44 pmSpokane
$327
Find similar
Alaska Airlines
Feb 1
BOI6:23 amBoise Air Term. Gowen Fld
6h 31m
1 stop
STL1:54 pmLambert-St Louis
Feb 4
STL2:50 pmLambert-St Louis
7h 15m
1 stop
BOI9:05 pmBoise Air Term. Gowen Fld
$330
Find similar

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 diciembre 27, 2025.
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

sáb. 2/28

10:41 am-9:38 pm

2 stops9h 57m

Lambert-St Louis

mié. 3/4

2:22 pm-9:56 pm

2 stops8h 34m

$256

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

jue. 3/5

1:25 pm-11:23 pm

2 stops7h 58m

Lambert-St Louis

lun. 3/9

3:05 pm-10:33 pm

2 stops9h 28m

$256

HaileySt. Louis

SUN - STL

SUNSTL

Hailey Sun Valley-Friedman

sáb. 1/24

2:31 pm-8:58 pm

1 stop5h 27m

Lambert-St Louis

sáb. 1/31

4:15 pm-9:29 pm

1 stop6h 14m

$269

HaileySt. Louis

SUN - STL

SUNSTL

Hailey Sun Valley-Friedman

sáb. 1/24

8:00 am-8:58 pm

2 stops11h 58m

Lambert-St Louis

sáb. 1/31

1:15 pm-9:29 pm

2 stops9h 14m

$279

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

mar. 1/20

6:00 am-4:14 pm

1 stop8h 14m

Lambert-St Louis

lun. 2/2

11:55 am-6:49 pm

1 stop8h 54m

$290

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

dom. 2/8

8:58 pm-8:50 pm

1 stop21h 52m

Lambert-St Louis

sáb. 2/21

6:41 pm-2:16 pm

2 stops21h 35m

$294

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

sáb. 2/28

6:28 am-1:51 pm

1 stop6h 23m

Lambert-St Louis

mié. 3/4

7:00 am-2:58 pm

1 stop8h 58m

$295

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

dom. 2/8

8:58 pm-8:50 pm

1 stop21h 52m

Lambert-St Louis

sáb. 2/21

2:51 pm-2:16 pm

1 stop25h 25m

$306

BoiseSt. Louis

BOI - STL

BOISTL

Boise Air Term. Gowen Fld

jue. 1/29

6:13 am-1:53 pm

1 stop6h 40m

Lambert-St Louis

lun. 2/2

6:00 am-1:08 pm

1 stop8h 08m

$326

SpokaneSt. Louis

GEG - STL

GEGSTL

Spokane

mié. 1/28

5:45 am-1:54 pm

1 stop6h 09m

Lambert-St Louis

dom. 2/1

2:50 pm-12:44 pm

1 stop23h 54m

$327

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 18 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, September 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 $301. The month of April is another great option to travel to St. Louis, with average flight prices from Idaho averaging around $310.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Tuesday when prices can be found for as low as $391. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $561. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Idaho in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $410 when looking at flights departing in the afternoon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $496 per ticket.

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

You could potentially save up to 31% 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 $179Free CancellationRating
7.9
8,019 reviews
Search Delta flights
American AirlinesPriceFrom $226Free CancellationRating
7.2
11,072 reviews
Search American Airlines flights
Alaska AirlinesPriceFrom $278Free CancellationRating
8.0
11,551 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $281Free CancellationRating
8.0
4,256 reviews
Search Southwest flights
United AirlinesPriceFrom $286Free CancellationRating
7.4
9,113 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
O'Fallon
Florissant
Fenton
Collinsville
St. Peters
Wentzville
Alton
Farmington
Clayton
Glencoe
Eureka
Festus
Edwardsville
Litchfield
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.

An easier way to manage your St. Louis trip

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