$112+ 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 4/8. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
Apr 26 — May 31
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
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
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
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
Cheapest
Best
Last-minute
One-way
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 March 27, 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 March 27, 2026.
This CheapOair deal was found by Cheapflights users on 3/24. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- BOI
1 stop15h 52m
Frontier
Sun 4/1212:03 pm
BOI
- STL
1 stop20h 45m
Frontier
Deal found 3/24![Frontier logo]()
$211
This Kiwi.com deal was found by Cheapflights users on 3/25. 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.
Mon 5/48:17 pm
STL
- BOI
1 stop17h 10m
Frontier
Tue 5/121:22 pm
BOI
- STL
2 stops18h 33m
Frontier
Deal found 3/25![Frontier logo]()
$217
This Delta deal was found by Cheapflights users on 3/27. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/287:00 am
STL
- BOI
1 stop6h 02m
Delta
Wed 5/1312:55 pm
BOI
- STL
1 stop5h 08m
Delta
Deal found 3/27![Delta logo]()
$263
This Delta deal was found by Cheapflights users on 3/27. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/202:27 pm
STL
- BOI
1 stop8h 17m
Delta
Thu 5/2811:39 pm
BOI
- STL
1 stop7h 39m
Delta
Deal found 3/27![Delta logo]()
$290
This Southwest deal was found by Cheapflights users on 3/27. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/285:40 pm
STL
- BOI
2 stops7h 45m
Southwest
Wed 5/134:05 pm
BOI
- STL
1 stop6h 10m
Southwest
Deal found 3/27![Southwest logo]()
$295
This Delta deal was found by Cheapflights users on 3/24. 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.
Wed 5/65:35 pm
STL
- BOI
1 stop6h 35m
Delta
Tue 5/129:16 pm
BOI
- STL
2 stops10h 30m
Delta
Deal found 3/24![Delta logo]()
$298
This American Airlines deal was found by Cheapflights users on 3/25. 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.
Wed 4/227:05 am
STL
- GEG
1 stop7h 27m
American Airlines
Sat 4/251:22 pm
GEG
- STL
1 stop8h 24m
American Airlines
Deal found 3/25![American Airlines logo]()
$305
This Delta deal was found by Cheapflights users on 3/24. 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.
Mon 4/207:00 am
STL
- GEG
1 stop7h 13m
Delta
Wed 4/225:10 pm
GEG
- STL
1 stop5h 15m
Delta
Deal found 3/24![Delta logo]()
$312
This Delta deal was found by Cheapflights users on 3/24. 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.
Sat 5/96:21 am
STL
- BOI
1 stop7h 57m
Delta
Sat 5/162:23 pm
BOI
- STL
1 stop7h 58m
Delta
Deal found 3/24![Delta logo]()
$317
This Alaska Airlines deal was found by Cheapflights users on 3/26. 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 10/273:24 pm
STL
- IDA
1 stop8h 15m
Alaska Airlines
Sat 10/314:03 pm
IDA
- STL
1 stop6h 56m
Alaska Airlines
Deal found 3/26![Alaska Airlines logo]()
$319
This Southwest deal was found by Cheapflights users on 3/24. 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.
Sat 5/94:45 pm
STL
- BOI
1 stop6h 20m
Southwest
Sat 5/1611:00 am
BOI
- STL
2 stops8h 25m
Southwest
Deal found 3/24![Southwest logo]()
$322
This United Airlines deal was found by Cheapflights users on 3/25. 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.
Wed 4/2210:00 am
STL
- GEG
2 stops13h 11m
United Airlines
Sat 4/255:05 am
GEG
- STL
1 stop6h 03m
United Airlines
Deal found 3/25![United Airlines logo]()
$325
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 March 27, 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 March 27, 2026.
This Delta deal was found by Cheapflights users on 3/26. 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.
Wed 5/202:27 pm
STL
- BOI
1 stop8h 17m
Delta
Thu 5/282:23 pm
BOI
- STL
1 stop7h 58m
Delta
Deal found 3/26![Delta logo]()
$290
This Southwest deal was found by Cheapflights users on 3/27. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/285:40 pm
STL
- BOI
2 stops7h 45m
Southwest
Wed 5/134:05 pm
BOI
- STL
1 stop6h 10m
Southwest
Deal found 3/27![Southwest logo]()
$295
This United Airlines deal was found by Cheapflights users on 3/23. 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.
Tue 4/289:10 am
STL
- BOI
2 stops13h 12m
United Airlines
Sat 5/212:30 pm
BOI
- STL
2 stops9h 49m
United Airlines
Deal found 3/23![United Airlines logo]()
$390
This Alaska Airlines deal was found by Cheapflights users on 3/24. 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 4/284:46 pm
STL
- BOI
1 stop8h 13m
Alaska Airlines
Sat 5/26:00 am
BOI
- STL
1 stop8h 50m
Alaska Airlines
Deal found 3/24![Alaska Airlines logo]()
$403
This Delta deal was found by Cheapflights users on 3/24. 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.
Sat 5/96:21 am
STL
- BOI
1 stop7h 57m
Delta
Sat 5/162:23 pm
BOI
- STL
1 stop7h 58m
Delta
Deal found 3/24![Delta logo]()
$317
This Southwest deal was found by Cheapflights users on 3/24. 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.
Sat 5/94:45 pm
STL
- BOI
1 stop6h 20m
Southwest
Sat 5/1611:00 am
BOI
- STL
2 stops8h 25m
Southwest
Deal found 3/24![Southwest logo]()
$322
This Delta deal was found by Cheapflights users on 3/22. 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 4/216:45 pm
STL
- IDA
1 stop4h 55m
Delta
Tue 4/286:58 pm
IDA
- STL
2 stops12h 32m
Delta
Deal found 3/22![Delta logo]()
$339
This United Airlines deal was found by Cheapflights users on 3/23. 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 5/94:15 pm
STL
- GEG
1 stop7h 01m
United Airlines
Wed 5/135:00 am
GEG
- STL
1 stop6h 13m
United Airlines
Deal found 3/23![United Airlines logo]()
$395
This Delta deal was found by Cheapflights users on 3/24. 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 4/176:00 am
STL
- BOI
1 stop8h 07m
Delta
Mon 4/2011:35 pm
BOI
- STL
1 stop7h 55m
Delta
Deal found 3/24![Delta logo]()
$344
This United Airlines deal was found by Cheapflights users on 3/23. 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.
Mon 6/81:13 pm
STL
- JAC
1 stop6h 29m
United Airlines
Sat 6/134:23 pm
JAC
- STL
1 stop6h 34m
United Airlines
Deal found 3/23![United Airlines logo]()
$407
This Alaska Airlines deal was found by Cheapflights users on 3/24. 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 4/207:00 am
STL
- IDA
1 stop10h 19m
Alaska Airlines
Wed 4/224:06 pm
IDA
- STL
1 stop6h 53m
Alaska Airlines
Deal found 3/24![Alaska Airlines logo]()
$499
This Southwest deal was found by Cheapflights users on 3/22. 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 8/205:55 am
STL
- GEG
1 stop7h 45m
Southwest
Mon 8/246:00 am
GEG
- STL
1 stop8h 20m
Southwest
Deal found 3/22![Southwest logo]()
$457
This Delta deal was found by Cheapflights users on 3/23. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/82:12 pm
STL
- JAC
1 stop5h 50m
Delta
Sun 4/125:50 pm
JAC
- STL
1 stop5h 31m
Delta
Deal found 3/23![Delta logo]()
$391
This United Airlines deal was found by Cheapflights users on 3/22. 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 6/201:38 pm
STL
- JAC
1 stop5h 16m
United Airlines
Wed 6/244:23 pm
JAC
- STL
1 stop6h 34m
United Airlines
Deal found 3/22![United Airlines logo]()
$446
This Southwest deal was found by Cheapflights users on 3/23. 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 7/205:05 am
STL
- GEG
2 stops8h 35m
Southwest
Thu 7/235:00 am
GEG
- STL
1 stop9h 05m
Southwest
Deal found 3/23![Southwest logo]()
$462
This Delta deal was found by Cheapflights users on 3/27. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/172:20 pm
STL
- BOI
2 stops9h 04m
Delta
Mon 4/273:23 pm
BOI
- STL
1 stop6h 50m
Delta
Deal found 3/27![Delta logo]()
$406
This Kiwi.com deal was found by Cheapflights users on 3/24. 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.
Fri 5/87:00 am
STL
- IDA
1 stop9h 29m
Alaska Airlines
Fri 5/156:00 am
IDA
- STL
1 stop8h 16m
Alaska Airlines
Deal found 3/24![Alaska Airlines logo]()
$558
This United Airlines deal was found by Cheapflights users on 3/25. 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 6/65:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Tue 6/95:54 pm
IDA
- STL
1 stop5h 03m
United Airlines
Deal found 3/25![United Airlines logo]()
$465
This Southwest deal was found by Cheapflights users on 3/22. 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 5/213:50 pm
STL
- GEG
2 stops10h 40m
Southwest
Sun 5/2410:10 am
GEG
- STL
2 stops9h 15m
Southwest
Deal found 3/22![Southwest logo]()
$472
This Delta deal was found by Cheapflights users on 3/25. 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.
Fri 5/157:59 pm
STL
- GEG
1 stop5h 36m
Delta
Mon 5/187:23 pm
GEG
- STL
2 stops13h 09m
Delta
Deal found 3/25![Delta logo]()
$415
This United Airlines deal was found by Cheapflights users on 3/22. 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 5/98:46 am
STL
- WYS
1 stop8h 21m
United Airlines
Sat 5/162:03 pm
WYS
- STL
2 stops8h 16m
United Airlines
Deal found 3/22![United Airlines logo]()
$467
This Southwest deal was found by Cheapflights users on 3/25. 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.
Tue 7/145:20 pm
STL
- GEG
1 stop6h 55m
Southwest
Mon 7/275:00 am
GEG
- STL
1 stop9h 05m
Southwest
Deal found 3/25![Southwest logo]()
$477
This Delta deal was found by Cheapflights users on 3/25. 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 4/96:00 am
STL
- JAC
2 stops11h 47m
Delta
Mon 4/135:11 pm
JAC
- STL
1 stop6h 14m
Delta
Deal found 3/25![Delta logo]()
$430
This United Airlines deal was found by Cheapflights users on 3/25. 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.
Thu 6/185:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Mon 6/224:10 pm
IDA
- STL
1 stop6h 47m
United Airlines
Deal found 3/25![United Airlines logo]()
$491
This Delta deal was found by Cheapflights users on 3/24. 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.
Sat 5/95:00 pm
STL
- JAC
1 stop5h 29m
Delta
Sat 5/167:45 am
JAC
- STL
2 stops8h 01m
Delta
Deal found 3/24![Delta logo]()
$430
This United Airlines deal was found by Cheapflights users on 3/23. 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.
Mon 8/35:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Sat 8/810:35 am
IDA
- STL
1 stop4h 58m
United Airlines
Deal found 3/23![United Airlines logo]()
$515
This Delta deal was found by Cheapflights users on 3/22. 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 4/237:00 am
STL
- GEG
2 stops9h 49m
Delta
Sun 4/261:07 pm
GEG
- STL
2 stops9h 18m
Delta
Deal found 3/22![Delta logo]()
$450
This United Airlines deal was found by Cheapflights users on 3/23. 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 8/289:00 am
STL
- WYS
1 stop8h 07m
United Airlines
Sat 9/55:45 pm
WYS
- STL
1 stop5h 05m
United Airlines
Deal found 3/23![United Airlines logo]()
$525
This Delta deal was found by Cheapflights users on 3/22. 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 6/191:59 pm
STL
- JAC
2 stops8h 21m
Delta
Thu 6/256:06 pm
JAC
- STL
1 stop5h 33m
Delta
Deal found 3/22![Delta logo]()
$456
This Delta deal was found by Cheapflights users on 3/23. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/203:40 pm
STL
- GEG
1 stop7h 53m
Delta
Thu 7/2310:48 pm
GEG
- STL
1 stop7h 31m
Delta
Deal found 3/23![Delta logo]()
$457
Last-minute flights from St. Louis to IdahoDiscover last-minute flight deals from St. Louis to Idaho. Data last updated March 27, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Idaho. Data last updated March 27, 2026 and is based on user searches.
This CheapOair deal was found by Cheapflights users on 3/24. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- BOI
1 stop15h 52m
Frontier
Sun 4/1212:03 pm
BOI
- STL
1 stop20h 45m
Frontier
Deal found 3/24![Frontier logo]()
$211
This United Airlines deal was found by Cheapflights users on 3/26. 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 4/144:30 pm
STL
- GEG
1 stop6h 41m
United Airlines
Sat 4/181:46 pm
GEG
- STL
1 stop5h 08m
United Airlines
Deal found 3/26![United Airlines logo]()
$344
This Delta deal was found by Cheapflights users on 3/24. 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.
Mon 4/207:00 am
STL
- GEG
1 stop7h 13m
Delta
Wed 4/225:10 pm
GEG
- STL
1 stop5h 15m
Delta
Deal found 3/24![Delta logo]()
$312
This Southwest deal was found by Cheapflights users on 3/24. 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.
Mon 4/205:15 pm
STL
- GEG
2 stops9h 15m
Southwest
Wed 4/221:45 pm
GEG
- STL
1 stop7h 25m
Southwest
Deal found 3/24![Southwest logo]()
$329
This Southwest deal was found by Cheapflights users on 3/23. 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 4/207:20 pm
STL
- GEG
1 stop7h 15m
Southwest
Mon 4/272:50 pm
GEG
- STL
1 stop7h 00m
Southwest
Deal found 3/23![Southwest logo]()
$343
This Orbitz deal was found by Cheapflights users on 3/22. 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 4/213:50 pm
STL
- IDA
1 stop8h 02m
Alaska Airlines
Tue 4/284:06 pm
IDA
- STL
1 stop6h 53m
Alaska Airlines
Deal found 3/22![Alaska Airlines logo]()
$319
This Delta deal was found by Cheapflights users on 3/22. 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 4/216:45 pm
STL
- IDA
1 stop4h 55m
Delta
Tue 4/286:58 pm
IDA
- STL
2 stops12h 32m
Delta
Deal found 3/22![Delta logo]()
$339
This American Airlines deal was found by Cheapflights users on 3/25. 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.
Wed 4/227:05 am
STL
- GEG
1 stop7h 27m
American Airlines
Sat 4/251:22 pm
GEG
- STL
1 stop8h 24m
American Airlines
Deal found 3/25![American Airlines logo]()
$305
This United Airlines deal was found by Cheapflights users on 3/25. 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.
Wed 4/2210:00 am
STL
- GEG
2 stops13h 11m
United Airlines
Sat 4/255:05 am
GEG
- STL
1 stop6h 03m
United Airlines
Deal found 3/25![United Airlines logo]()
$325
This Delta deal was found by Cheapflights users on 3/27. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/287:00 am
STL
- BOI
1 stop6h 02m
Delta
Wed 5/1312:55 pm
BOI
- STL
1 stop5h 08m
Delta
Deal found 3/27![Delta logo]()
$263
This Southwest deal was found by Cheapflights users on 3/27. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/285:40 pm
STL
- BOI
2 stops7h 45m
Southwest
Wed 5/134:05 pm
BOI
- STL
1 stop6h 10m
Southwest
Deal found 3/27![Southwest logo]()
$295
This American Airlines deal was found by Cheapflights users on 3/26. 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.
Thu 4/307:05 am
STL
- GEG
1 stop7h 27m
American Airlines
Sat 5/21:22 pm
GEG
- STL
1 stop6h 55m
American Airlines
Deal found 3/26![American Airlines logo]()
$336
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 March 27, 2026.
Search for one-way flight options from St. Louis to Idaho. Find affordable one-way fares based on user searches. Data last updated March 27, 2026.
This CheapOair deal was found by Cheapflights users on 3/25. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- BOI
1 stop15h 52m
Frontier
Deal found 3/25![Frontier logo]()
$112
This American Airlines deal was found by Cheapflights users on 3/26. 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.
Wed 5/67:05 am
STL
- BOI
1 stop6h 44m
American Airlines
Deal found 3/26![American Airlines logo]()
$132
This CheapOair deal was found by Cheapflights users on 3/27. 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 01m
Frontier
Deal found 3/27![Frontier logo]()
$137
This Kiwi.com deal was found by Cheapflights users on 3/26. 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.
Wed 5/66:51 pm
STL
- BOI
2 stops18h 36m
Frontier
Deal found 3/26![Frontier logo]()
$142
This American Airlines deal was found by Cheapflights users on 3/26. 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.
Thu 4/235:51 am
STL
- BOI
1 stop7h 58m
American Airlines
Deal found 3/26![American Airlines logo]()
$159
This Trip.com deal was found by Cheapflights users on 3/26. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/118:16 pm
STL
- BOI
1 stop15h 52m
Frontier
Deal found 3/26![Frontier logo]()
$165
This American Airlines deal was found by Cheapflights users on 3/23. 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.
Sat 5/235:25 am
STL
- GEG
1 stop8h 36m
American Airlines
Deal found 3/23![American Airlines logo]()
$178
This American Airlines deal was found by Cheapflights users on 3/23. 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.
Fri 5/297:03 am
STL
- BOI
1 stop9h 04m
American Airlines
Deal found 3/23![American Airlines logo]()
$186
This Alaska Airlines deal was found by Cheapflights users on 3/25. 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.
Sat 8/155:33 pm
STL
- JAC
2 stops22h 34m
Alaska Airlines
Deal found 3/25![Alaska Airlines logo]()
$191
This Expedia deal was found by Cheapflights users on 3/23. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/27:41 pm
STL
- JAC
1 stop16h 39m
Alaska Airlines
Deal found 3/23![Alaska Airlines logo]()
$201
This Delta deal was found by Cheapflights users on 3/26. 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.
Thu 4/237:00 am
STL
- BOI
2 stops10h 14m
Delta
Deal found 3/26![Delta logo]()
$203
This American Airlines deal was found by Cheapflights users on 3/27. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/75:29 am
STL
- BOI
1 stop6h 52m
American Airlines
Deal found 3/27![American Airlines logo]()
$204
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 March 27, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $211 (CheapOair) |
One-way from | $112 (CheapOair) |
Popular in | February |
Cheapest in | January |
Average price | $538 |
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 March 27, 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. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Wed 5/20
2:27 pm-9:44 pm
1 stop8h 17m
Boise Air Term. Gowen Fld
Thu 5/28
2:23 pm-11:21 pm
1 stop7h 58m
$290
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 4/28
5:40 pm-12:25 am
2 stops7h 45m
Boise Air Term. Gowen Fld
Wed 5/13
4:05 pm-11:15 pm
1 stop6h 10m
$295
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Sat 5/9
6:21 am-1:18 pm
1 stop7h 57m
Boise Air Term. Gowen Fld
Sat 5/16
2:23 pm-11:21 pm
1 stop7h 58m
$317
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Sat 5/9
4:45 pm-10:05 pm
1 stop6h 20m
Boise Air Term. Gowen Fld
Sat 5/16
11:00 am-8:25 pm
2 stops8h 25m
$322
St. LouisIdaho Falls
STL - IDA
STLIDA
Lambert-St Louis
Tue 4/21
6:45 pm-10:40 pm
1 stop4h 55m
Idaho Falls Fanning Field
Tue 4/28
6:58 pm-8:30 am
2 stops12h 32m
$339
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Fri 4/17
6:00 am-1:07 pm
1 stop8h 07m
Boise Air Term. Gowen Fld
Mon 4/20
11:35 pm-8:30 am
1 stop7h 55m
$344
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 4/28
9:10 am-9:22 pm
2 stops13h 12m
Boise Air Term. Gowen Fld
Sat 5/2
12:30 pm-11:19 pm
2 stops9h 49m
$390
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Wed 4/8
2:12 pm-7:02 pm
1 stop5h 50m
Jackson Hole
Sun 4/12
5:50 pm-12:21 am
1 stop5h 31m
$391
St. LouisSpokane
STL - GEG
STLGEG
Lambert-St Louis
Sat 5/9
4:15 pm-9:16 pm
1 stop7h 01m
Spokane
Wed 5/13
5:00 am-1:13 pm
1 stop6h 13m
$395
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 4/28
4:46 pm-11:59 pm
1 stop8h 13m
Boise Air Term. Gowen Fld
Sat 5/2
6:00 am-3:50 pm
1 stop8h 50m
$403
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, September is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $186). Flying from St. Louis to Idaho in February is currently the most expensive (average of $556). 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?
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 March 27, 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.
Food
7.0
Entertainment
7.5
Boarding
8.1
Overall
8.0
Crew
8.6
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Entertainment
7.5
Boarding
8.1
Overall
8.0
Crew
8.6
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Entertainment
7.5
Boarding
8.1
Overall
8.0
Crew
8.6
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Entertainment
7.5
Boarding
8.1
Overall
8.0
Crew
8.6
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Entertainment
7.5
Boarding
8.1
Overall
8.0
Crew
8.6
Comfort
8.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
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.
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
Alternative routes
Complete your trip
Flights by cabin class
Other flight options
Popular flights
Top destinations
Alternative routes for St. Louis to Idaho
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Idaho by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from St. Louis to Idaho by cabin class
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 March 27, 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 March 27, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$163 | Average$372 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$186 | Average$366 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$290 | Average$470 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$296 | Average$421 | FlexibilityNo cancel fee | On-time63% |