$110+ Cheap flights from St. Louis (STL) to Idaho
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/31. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
Aug 27 — Sep 31
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Idaho with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from St. Louis to Idaho
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Cheapest flights from St. Louis to IdahoExplore the most affordable flight options available from St. Louis to Idaho. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 28, 2026.
Explore the most affordable flight options available from St. Louis to Idaho. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 28, 2026.
This Frontier deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/1012:17 pm
STL
- BOI
1 stop26h 38m
Frontier
Thu 9/172:50 pm
BOI
- STL
1 stop19h 37m
Frontier
Deal found 7/28![Frontier logo]()
$252
This CheapOair deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/1612:17 pm
STL
- BOI
1 stop26h 38m
Frontier
Mon 9/212:50 pm
BOI
- STL
1 stop19h 42m
Frontier
Deal found 7/26![Frontier logo]()
$261
This Kiwi.com deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/208:10 pm
STL
- BOI
2 stops43h 47m
Frontier
Mon 10/263:52 pm
BOI
- STL
1 stop8h 25m
Frontier
Deal found 7/24![Frontier logo]()
$308
This Orbitz deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:02 am
STL
- BOI
1 stop8h 09m
Multiple Airlines
Mon 10/263:52 pm
BOI
- STL
1 stop8h 25m
Multiple Airlines
Deal found 7/24![Multiple Airlines logo]()
$310
This CheapOair deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2412:27 pm
STL
- BOI
1 stop26h 28m
Frontier
Sun 9/272:50 pm
BOI
- STL
1 stop19h 27m
Frontier
Deal found 7/27![Frontier logo]()
$324
This American Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:00 am
STL
- IDA
1 stop8h 09m
American Airlines
Thu 8/272:20 pm
IDA
- STL
1 stop7h 21m
American Airlines
Deal found 7/26![American Airlines logo]()
$329
This Expedia deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:35 am
STL
- BOI
1 stop7h 01m
Multiple Airlines
Sun 8/3012:24 pm
BOI
- STL
1 stop5h 49m
Multiple Airlines
Deal found 7/26![Multiple Airlines logo]()
$344
This Alaska Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:35 am
STL
- IDA
1 stop9h 45m
Alaska Airlines
Sat 8/296:18 am
IDA
- STL
1 stop6h 48m
Alaska Airlines
Deal found 7/27![Alaska Airlines logo]()
$354
This United Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/54:40 pm
STL
- IDA
1 stop5h 38m
United Airlines
Sat 9/124:04 pm
IDA
- STL
1 stop6h 36m
United Airlines
Deal found 7/23![United Airlines logo]()
$358
This United Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/258:00 am
STL
- IDA
2 stops10h 16m
United Airlines
Thu 8/272:25 pm
IDA
- STL
1 stop5h 21m
United Airlines
Deal found 7/26![United Airlines logo]()
$360
This Booking.com deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/143:19 pm
STL
- GEG
1 stop9h 06m
Alaska Airlines
Sat 9/195:12 am
GEG
- STL
1 stop9h 58m
Alaska Airlines
Deal found 7/23![Alaska Airlines logo]()
$363
This American Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/279:32 am
STL
- BOI
1 stop5h 57m
American Airlines
Mon 8/3112:12 pm
BOI
- STL
1 stop7h 14m
American Airlines
Deal found 7/23![American Airlines logo]()
$363
Best flights from St. Louis to IdahoDiscover carefully curated flight deals from St. Louis to Idaho that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 28, 2026.
Discover carefully curated flight deals from St. Louis to Idaho that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 28, 2026.
This Alaska Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:35 am
STL
- IDA
1 stop9h 45m
Alaska Airlines
Sat 8/296:18 am
IDA
- STL
1 stop6h 48m
Alaska Airlines
Deal found 7/25![Alaska Airlines logo]()
$354
This United Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/54:40 pm
STL
- IDA
1 stop5h 38m
United Airlines
Sat 9/124:04 pm
IDA
- STL
1 stop6h 36m
United Airlines
Deal found 7/23![United Airlines logo]()
$358
This Southwest deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/206:05 pm
STL
- GEG
1 stop5h 55m
Southwest
Tue 8/256:15 am
GEG
- STL
2 stops9h 40m
Southwest
Deal found 7/24![Southwest logo]()
$374
This Delta deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/242:25 pm
STL
- BOI
2 stops10h 33m
Delta
Tue 9/296:45 am
BOI
- STL
2 stops9h 52m
Delta
Deal found 7/28![Delta logo]()
$404
This United Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/258:00 am
STL
- IDA
2 stops10h 16m
United Airlines
Thu 8/272:25 pm
IDA
- STL
1 stop5h 21m
United Airlines
Deal found 7/26![United Airlines logo]()
$360
This Alaska Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/67:36 pm
STL
- BOI
1 stop15h 16m
Alaska Airlines
Mon 9/288:25 pm
BOI
- STL
1 stop19h 45m
Alaska Airlines
Deal found 7/24![Alaska Airlines logo]()
$368
This Southwest deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/297:10 am
STL
- GEG
1 stop6h 55m
Southwest
Sat 9/511:20 am
GEG
- STL
2 stops9h 05m
Southwest
Deal found 7/28![Southwest logo]()
$374
This Alaska Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/177:00 am
STL
- GEG
1 stop9h 22m
Alaska Airlines
Wed 11/185:00 am
GEG
- STL
1 stop7h 15m
Alaska Airlines
Deal found 7/26![Alaska Airlines logo]()
$369
This Delta deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/207:45 pm
STL
- GEG
1 stop6h 08m
Delta
Tue 8/255:00 pm
GEG
- STL
1 stop5h 41m
Delta
Deal found 7/25![Delta logo]()
$410
This United Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/75:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Thu 8/134:04 pm
IDA
- STL
1 stop6h 27m
United Airlines
Deal found 7/24![United Airlines logo]()
$379
This Southwest deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/106:15 pm
STL
- GEG
1 stop6h 30m
Southwest
Thu 9/176:00 am
GEG
- STL
2 stops10h 25m
Southwest
Deal found 7/26![Southwest logo]()
$401
This Alaska Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/176:02 am
STL
- GEG
1 stop6h 58m
Alaska Airlines
Mon 8/247:24 pm
GEG
- STL
1 stop19h 46m
Alaska Airlines
Deal found 7/24![Alaska Airlines logo]()
$369
This United Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/119:00 am
STL
- WYS
1 stop5h 20m
United Airlines
Sat 8/155:45 pm
WYS
- STL
1 stop4h 55m
United Airlines
Deal found 7/27![United Airlines logo]()
$380
This Delta deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/2512:52 pm
STL
- IDA
2 stops10h 40m
Delta
Thu 8/277:00 pm
IDA
- STL
2 stops12h 08m
Delta
Deal found 7/26![Delta logo]()
$439
This Alaska Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/277:02 am
STL
- BOI
1 stop8h 09m
Alaska Airlines
Wed 10/284:18 pm
BOI
- STL
1 stop6h 41m
Alaska Airlines
Deal found 7/24![Alaska Airlines logo]()
$369
This Southwest deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/151:40 pm
STL
- GEG
2 stops10h 50m
Southwest
Wed 9/237:30 am
GEG
- STL
2 stops9h 15m
Southwest
Deal found 7/24![Southwest logo]()
$406
This United Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/115:10 am
STL
- IDA
1 stop5h 41m
United Airlines
Sat 8/154:04 pm
IDA
- STL
1 stop6h 36m
United Airlines
Deal found 7/27![United Airlines logo]()
$401
This Alaska Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/273:04 pm
STL
- BOI
1 stop8h 29m
Alaska Airlines
Mon 8/312:17 pm
BOI
- STL
1 stop8h 42m
Alaska Airlines
Deal found 7/26![Alaska Airlines logo]()
$369
This Southwest deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/116:05 pm
STL
- BOI
1 stop5h 35m
Southwest
Fri 9/1812:10 pm
BOI
- STL
1 stop5h 55m
Southwest
Deal found 7/25![Southwest logo]()
$412
This Alaska Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/246:29 am
STL
- BOI
1 stop7h 06m
Alaska Airlines
Tue 9/296:23 am
BOI
- STL
1 stop6h 58m
Alaska Airlines
Deal found 7/25![Alaska Airlines logo]()
$369
This Southwest deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/143:45 pm
STL
- GEG
2 stops8h 20m
Southwest
Sat 9/1911:05 am
GEG
- STL
2 stops9h 20m
Southwest
Deal found 7/23![Southwest logo]()
$423
This Delta deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/112:32 pm
STL
- PIH
1 stop4h 51m
Delta
Tue 8/187:00 pm
PIH
- STL
1 stop4h 41m
Delta
Deal found 7/28![Delta logo]()
$537
This United Airlines deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/115:10 am
STL
- IDA
1 stop5h 41m
United Airlines
Tue 8/182:25 pm
IDA
- STL
1 stop5h 21m
United Airlines
Deal found 7/28![United Airlines logo]()
$444
This Alaska Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:08 pm
STL
- BOI
1 stop6h 47m
Alaska Airlines
Wed 8/266:23 am
BOI
- STL
1 stop6h 43m
Alaska Airlines
Deal found 7/23![Alaska Airlines logo]()
$388
This Delta deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/162:22 pm
STL
- JAC
1 stop6h 04m
Delta
Sun 10/185:27 pm
JAC
- STL
1 stop6h 07m
Delta
Deal found 7/24![Delta logo]()
$543
This United Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/161:36 pm
STL
- JAC
1 stop5h 13m
United Airlines
Mon 10/192:48 pm
JAC
- STL
1 stop4h 48m
United Airlines
Deal found 7/23![United Airlines logo]()
$491
This Alaska Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/36:08 pm
STL
- GEG
1 stop7h 03m
Alaska Airlines
Sun 9/611:45 am
GEG
- STL
1 stop10h 14m
Alaska Airlines
Deal found 7/25![Alaska Airlines logo]()
$409
This United Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/299:00 am
STL
- JAC
1 stop7h 28m
United Airlines
Sun 9/64:25 pm
JAC
- STL
1 stop6h 06m
United Airlines
Deal found 7/26![United Airlines logo]()
$496
This Alaska Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/206:08 pm
STL
- GEG
1 stop7h 03m
Alaska Airlines
Tue 8/255:12 am
GEG
- STL
1 stop9h 58m
Alaska Airlines
Deal found 7/24![Alaska Airlines logo]()
$414
This United Airlines deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/118:50 am
STL
- JAC
2 stops9h 59m
United Airlines
Tue 8/187:00 am
JAC
- STL
1 stop4h 40m
United Airlines
Deal found 7/28![United Airlines logo]()
$504
Last-minute flights from St. Louis to IdahoDiscover last-minute flight deals from St. Louis to Idaho. Data last updated July 28, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Idaho. Data last updated July 28, 2026 and is based on user searches.
This United Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/75:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Thu 8/134:04 pm
IDA
- STL
1 stop6h 27m
United Airlines
Deal found 7/24![United Airlines logo]()
$379
This United Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/119:00 am
STL
- WYS
1 stop5h 20m
United Airlines
Sat 8/155:45 pm
WYS
- STL
1 stop4h 55m
United Airlines
Deal found 7/27![United Airlines logo]()
$380
This American Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/155:42 am
STL
- BOI
2 stops8h 42m
American Airlines
Tue 8/181:55 pm
BOI
- STL
2 stops8h 47m
American Airlines
Deal found 7/25![American Airlines logo]()
$380
This Alaska Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/176:02 am
STL
- GEG
1 stop6h 58m
Alaska Airlines
Mon 8/247:24 pm
GEG
- STL
1 stop19h 46m
Alaska Airlines
Deal found 7/24![Alaska Airlines logo]()
$369
This Southwest deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/206:05 pm
STL
- GEG
1 stop5h 55m
Southwest
Tue 8/256:15 am
GEG
- STL
2 stops9h 40m
Southwest
Deal found 7/24![Southwest logo]()
$374
This American Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:00 am
STL
- IDA
1 stop8h 09m
American Airlines
Thu 8/272:20 pm
IDA
- STL
1 stop7h 21m
American Airlines
Deal found 7/26![American Airlines logo]()
$329
This Expedia deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:35 am
STL
- BOI
1 stop7h 01m
Multiple Airlines
Sun 8/3012:24 pm
BOI
- STL
1 stop5h 49m
Multiple Airlines
Deal found 7/26![Multiple Airlines logo]()
$344
This Alaska Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/256:35 am
STL
- IDA
1 stop9h 45m
Alaska Airlines
Sat 8/296:18 am
IDA
- STL
1 stop6h 48m
Alaska Airlines
Deal found 7/26![Alaska Airlines logo]()
$354
This United Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/258:00 am
STL
- IDA
2 stops10h 16m
United Airlines
Thu 8/272:25 pm
IDA
- STL
1 stop5h 21m
United Airlines
Deal found 7/26![United Airlines logo]()
$360
This American Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/279:32 am
STL
- BOI
1 stop5h 57m
American Airlines
Mon 8/3112:12 pm
BOI
- STL
1 stop7h 14m
American Airlines
Deal found 7/23![American Airlines logo]()
$363
This Alaska Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/273:04 pm
STL
- BOI
1 stop8h 29m
Alaska Airlines
Mon 8/311:15 pm
BOI
- STL
1 stop9h 44m
Alaska Airlines
Deal found 7/27![Alaska Airlines logo]()
$369
This Southwest deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/296:50 am
STL
- GEG
2 stops9h 45m
Southwest
Sat 9/57:05 am
GEG
- STL
2 stops6h 30m
Southwest
Deal found 7/28![Southwest logo]()
$379
One-way flights from St. Louis to IdahoSearch for one-way flight options from St. Louis to Idaho. Find affordable one-way fares based on user searches. Data last updated July 28, 2026.
Search for one-way flight options from St. Louis to Idaho. Find affordable one-way fares based on user searches. Data last updated July 28, 2026.
This Kiwi.com deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/317:58 pm
STL
- BOI
1 stop17h 31m
Frontier
Deal found 7/26![Frontier logo]()
$110
This United Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/235:10 am
STL
- IDA
1 stop5h 41m
United Airlines
Deal found 7/25![United Airlines logo]()
$165
This Kiwi.com deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/286:17 pm
STL
- GEG
3 stops41h 05m
Multiple Airlines
Deal found 7/25![Multiple Airlines logo]()
$172
This Southwest deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/185:25 pm
STL
- GEG
1 stop6h 40m
Southwest
Deal found 7/24![Southwest logo]()
$185
This Booking.com deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/276:08 pm
STL
- BOI
1 stop6h 47m
Alaska Airlines
Deal found 7/26![Alaska Airlines logo]()
$185
This United Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/139:00 am
STL
- IDA
1 stop7h 23m
United Airlines
Deal found 7/27![United Airlines logo]()
$190
This United Airlines deal was found by Cheapflights users on 7/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/2512:59 pm
STL
- GEG
2 stops9h 47m
United Airlines
Deal found 7/24![United Airlines logo]()
$190
This Southwest deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/273:45 pm
STL
- BOI
2 stops7h 50m
Southwest
Deal found 7/26![Southwest logo]()
$190
This United Airlines deal was found by Cheapflights users on 7/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/229:00 am
STL
- IDA
1 stop5h 29m
United Airlines
Deal found 7/25![United Airlines logo]()
$192
This United Airlines deal was found by Cheapflights users on 7/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/199:00 am
STL
- IDA
1 stop5h 29m
United Airlines
Deal found 7/26![United Airlines logo]()
$206
This CheapOair deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/38:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 7/27![Frontier logo]()
$206
This United Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/304:40 pm
STL
- JAC
1 stop5h 00m
United Airlines
Deal found 7/27![United Airlines logo]()
$215
Find flight deals from St. Louis to Idaho
Keep the following information in mind while searching for St. Louis to Idaho flight deals. Data was last updated July 28, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $261 (CheapOair) |
One-way from | $110 (Kiwi.com) |
Popular in | February |
Cheapest in | January |
Average price | $472 |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Idaho 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, Cheapflights users made 2,558,603 searches. Data last updated July 28, 2026.
Use the filters below to find and compare flights from St. Louis to Idaho that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisIdaho Falls
STL - IDA
STLIDA
Lambert-St Louis
Tue 8/25
6:35 am-3:20 pm
1 stop9h 45m
Idaho Falls Fanning Field
Sat 8/29
6:18 am-2:06 pm
1 stop6h 48m
$354
St. LouisIdaho Falls
STL - IDA
STLIDA
Lambert-St Louis
Sat 9/5
4:40 pm-9:18 pm
1 stop5h 38m
Idaho Falls Fanning Field
Sat 9/12
4:04 pm-11:40 pm
1 stop6h 36m
$358
St. LouisIdaho Falls
STL - IDA
STLIDA
Lambert-St Louis
Tue 8/25
8:00 am-5:16 pm
2 stops10h 16m
Idaho Falls Fanning Field
Thu 8/27
2:25 pm-8:46 pm
1 stop5h 21m
$360
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Sun 9/6
7:36 pm-9:52 am
1 stop15h 16m
Boise Air Term. Gowen Fld
Mon 9/28
8:25 pm-5:10 pm
1 stop19h 45m
$368
St. LouisSpokane
STL - GEG
STLGEG
Lambert-St Louis
Tue 11/17
7:00 am-2:22 pm
1 stop9h 22m
Spokane
Wed 11/18
5:00 am-2:15 pm
1 stop7h 15m
$369
St. LouisSpokane
STL - GEG
STLGEG
Lambert-St Louis
Mon 8/17
6:02 am-11:00 am
1 stop6h 58m
Spokane
Mon 8/24
7:24 pm-5:10 pm
1 stop19h 46m
$369
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 10/27
7:02 am-2:11 pm
1 stop8h 09m
Boise Air Term. Gowen Fld
Wed 10/28
4:18 pm-11:59 pm
1 stop6h 41m
$369
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Thu 8/27
3:04 pm-10:33 pm
1 stop8h 29m
Boise Air Term. Gowen Fld
Mon 8/31
2:17 pm-11:59 pm
1 stop8h 42m
$369
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Thu 9/24
6:29 am-12:35 pm
1 stop7h 06m
Boise Air Term. Gowen Fld
Tue 9/29
6:23 am-2:21 pm
1 stop6h 58m
$369
St. LouisSpokane
STL - GEG
STLGEG
Lambert-St Louis
Thu 8/20
6:05 pm-10:00 pm
1 stop5h 55m
Spokane
Tue 8/25
6:15 am-5:55 pm
2 stops9h 40m
$374
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from St. Louis to Idaho
Have a flexible travel schedule? Discover the best time to fly to Idaho from St. Louis with our price prediction graph.
STL-BOI
STL-IDA
STL-GEG
STL-JAC
STL-WYS
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from St. Louis to Idaho
STL-USID
STL-BOI
STL-IDA
STL-GEG
STL-JAC
What is the cheapest month to book a flight from St. Louis to Idaho?
Currently, January is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $359). Flying from St. Louis to Idaho in February is currently the most expensive (average of $566). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
How much does it cost to fly round-trip from St. Louis to Idaho?
Airfare is below average for this route at the moment.
St. Louis to Idaho flights typically cost between $357 and $676 in September.The cheapest round-trip price found within the last 5 days was $252 on Frontier (Sep 10-Sep 17).
Reviews of airlines servicing Idaho
Get insights into the airlines that provide service to Idaho. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Idaho. Reviews last updated July 28, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andUnited Airlines from St. Louis to Idaho to help guide your decision. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Overall
8.0
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Idaho. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Alternative routes for St. Louis to Idaho
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Complete your trip
Complete your trip to Idaho by adding a car rental and/or hotel reservation to your travel itinerary.
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Find flights from St. Louis to Idaho, based on your preferred cabin class, be it economy, premium economy, business, or first class.
St. Louis and Idaho flights
Browse other St. Louis and Idaho flight options. Last updated on July 28, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
St. Louis to Idaho flights
Consider these flights traveling from St. Louis to Idaho.
Top 4 airlines flying from St. Louis to Idaho
Discover the top 4 airlines that operate flights from St. Louis to Idaho. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated July 28, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$186 | Average$432 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$240 | Average$456 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$290 | Average$486 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$321 | Average$466 | FlexibilityNo cancel fee | On-time63% |