$92+ 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 5/9. Fares are subject to change and may not be available on all flights or dates of travel.
STL — BOI
May 19 — May 261
Round-trip
1 adult, Economy
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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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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 April 19, 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 April 19, 2026.
This Kiwi.com deal was found by Cheapflights users on 4/14. 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
- GEG
1 stop27h 38m
Multiple Airlines
Sun 5/109:19 pm
GEG
- STL
2 stops20h 04m
Multiple Airlines
Deal found 4/14![Multiple Airlines logo]()
$302
This Trip.com deal was found by Cheapflights users on 4/17. 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 5/97:00 am
STL
- BOI
1 stop9h 33m
Alaska Airlines
Sat 5/164:19 pm
BOI
- STL
1 stop6h 35m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$302
This Expedia deal was found by Cheapflights users on 4/15. 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.
Wed 5/135:33 pm
STL
- BOI
1 stop7h 25m
Alaska Airlines
Wed 5/204:19 pm
BOI
- STL
1 stop6h 35m
Alaska Airlines
Deal found 4/15![Alaska Airlines logo]()
$317
This Alaska Airlines deal was found by Cheapflights users on 4/14. 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.
Wed 5/135:33 pm
STL
- IDA
1 stop20h 44m
Alaska Airlines
Wed 5/206:00 am
IDA
- STL
1 stop8h 16m
Alaska Airlines
Deal found 4/14![Alaska Airlines logo]()
$339
This American Airlines deal was found by Cheapflights users on 4/15. 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 5/197:05 am
STL
- GEG
1 stop7h 18m
American Airlines
Tue 5/262:08 pm
GEG
- STL
1 stop7h 46m
American Airlines
Deal found 4/15![American Airlines logo]()
$347
This Expedia deal was found by Cheapflights users on 4/16. 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 6/305:37 pm
STL
- BOI
1 stop7h 11m
Multiple Airlines
Tue 7/71:04 pm
BOI
- STL
1 stop5h 19m
Multiple Airlines
Deal found 4/16![Multiple Airlines logo]()
$349
This Expedia deal was found by Cheapflights users on 4/17. 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 7/76:02 am
STL
- BOI
1 stop9h 05m
Multiple Airlines
Tue 7/141:04 pm
BOI
- STL
1 stop5h 19m
Multiple Airlines
Deal found 4/17![Multiple Airlines logo]()
$355
This American Airlines deal was found by Cheapflights users on 4/15. 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 5/305:25 am
STL
- BOI
1 stop6h 54m
American Airlines
Sat 6/63:11 pm
BOI
- STL
1 stop7h 45m
American Airlines
Deal found 4/15![American Airlines logo]()
$356
This American Airlines deal was found by Cheapflights users on 4/17. 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 5/267:00 am
STL
- BOI
1 stop8h 20m
American Airlines
Sat 5/303:11 pm
BOI
- STL
1 stop7h 43m
American Airlines
Deal found 4/17![American Airlines logo]()
$357
This Delta deal was found by Cheapflights users on 4/14. 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 6/135:00 pm
STL
- JAC
1 stop5h 20m
Delta
Thu 6/186:06 pm
JAC
- STL
1 stop5h 33m
Delta
Deal found 4/14![Delta logo]()
$359
This Southwest deal was found by Cheapflights users on 4/16. 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 6/25:35 pm
STL
- BOI
1 stop6h 55m
Southwest
Tue 6/93:00 pm
BOI
- STL
2 stops7h 40m
Southwest
Deal found 4/16![Southwest logo]()
$362
This Delta deal was found by Cheapflights users on 4/15. 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 7/211:18 am
STL
- JAC
2 stops11h 02m
Delta
Tue 7/76:06 pm
JAC
- STL
1 stop5h 31m
Delta
Deal found 4/15![Delta logo]()
$364
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 April 19, 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 April 19, 2026.
This Alaska Airlines deal was found by Cheapflights users on 4/14. 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.
Wed 5/135:33 pm
STL
- IDA
1 stop20h 44m
Alaska Airlines
Wed 5/206:00 am
IDA
- STL
1 stop8h 16m
Alaska Airlines
Deal found 4/14![Alaska Airlines logo]()
$339
This Southwest deal was found by Cheapflights users on 4/16. 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 6/25:35 pm
STL
- BOI
1 stop6h 55m
Southwest
Tue 6/93:00 pm
BOI
- STL
2 stops7h 40m
Southwest
Deal found 4/16![Southwest logo]()
$362
This Delta deal was found by Cheapflights users on 4/15. 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 6/38:53 am
STL
- JAC
2 stops9h 06m
Delta
Sun 6/76:06 pm
JAC
- STL
1 stop5h 33m
Delta
Deal found 4/15![Delta logo]()
$394
This United Airlines deal was found by Cheapflights users on 4/18. 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 5/234:45 pm
STL
- JAC
1 stop5h 13m
United Airlines
Sat 5/308:00 am
JAC
- STL
1 stop9h 17m
United Airlines
Deal found 4/18![United Airlines logo]()
$420
This Alaska Airlines deal was found by Cheapflights users on 4/16. 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.
Fri 5/155:33 pm
STL
- IDA
1 stop20h 44m
Alaska Airlines
Fri 5/224:03 pm
IDA
- STL
1 stop23h 34m
Alaska Airlines
Deal found 4/16![Alaska Airlines logo]()
$379
This Delta deal was found by Cheapflights users on 4/14. 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 7/306:30 am
STL
- JAC
2 stops11h 29m
Delta
Wed 8/51:21 pm
JAC
- STL
2 stops9h 32m
Delta
Deal found 4/14![Delta logo]()
$399
This Southwest deal was found by Cheapflights users on 4/17. 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 6/305:20 pm
STL
- BOI
2 stops8h 05m
Southwest
Tue 7/74:05 pm
BOI
- STL
1 stop6h 50m
Southwest
Deal found 4/17![Southwest logo]()
$412
This KAYAK deal was found by Cheapflights users on 4/15. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/132:27 pm
STL
- JAC
1 stop8h 02m
Delta
Wed 5/275:59 pm
JAC
- STL
1 stop5h 31m
Delta
Deal found 4/15![Delta logo]()
$401
This Southwest deal was found by Cheapflights users on 4/18. 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 6/64:55 pm
STL
- GEG
1 stop8h 25m
Southwest
Sun 6/146:40 pm
GEG
- STL
1 stop13h 10m
Southwest
Deal found 4/18![Southwest logo]()
$417
This United Airlines deal was found by Cheapflights users on 4/17. 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 6/135:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Tue 6/162:30 pm
IDA
- STL
1 stop5h 13m
United Airlines
Deal found 4/17![United Airlines logo]()
$459
This Alaska Airlines deal was found by Cheapflights users on 4/18. 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 6/27:41 pm
STL
- GEG
1 stop6h 18m
Alaska Airlines
Wed 6/31:59 pm
GEG
- STL
1 stop7h 55m
Alaska Airlines
Deal found 4/18![Alaska Airlines logo]()
$421
This Delta deal was found by Cheapflights users on 4/14. 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.
Sun 9/271:30 pm
STL
- JAC
1 stop7h 53m
Delta
Sat 10/35:30 pm
JAC
- STL
1 stop6h 06m
Delta
Deal found 4/14![Delta logo]()
$409
This Southwest deal was found by Cheapflights users on 4/14. 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 5/215:45 am
STL
- GEG
2 stops9h 05m
Southwest
Wed 5/277:00 am
GEG
- STL
2 stops8h 55m
Southwest
Deal found 4/14![Southwest logo]()
$426
This Alaska Airlines deal was found by Cheapflights users on 4/17. 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 6/24:12 pm
STL
- BOI
1 stop8h 46m
Alaska Airlines
Wed 6/34:19 pm
BOI
- STL
1 stop6h 35m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$428
This Delta deal was found by Cheapflights users on 4/15. 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 5/288:53 am
STL
- GEG
1 stop6h 18m
Delta
Sun 5/3110:40 pm
GEG
- STL
1 stop7h 38m
Delta
Deal found 4/15![Delta logo]()
$417
This Southwest deal was found by Cheapflights users on 4/14. 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 7/306:40 pm
STL
- BOI
1 stop5h 15m
Southwest
Sat 8/16:00 pm
BOI
- STL
1 stop6h 00m
Southwest
Deal found 4/14![Southwest logo]()
$445
This United Airlines deal was found by Cheapflights users on 4/15. 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 5/255:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Mon 6/154:10 pm
IDA
- STL
2 stops19h 01m
United Airlines
Deal found 4/15![United Airlines logo]()
$556
This Alaska Airlines deal was found by Cheapflights users on 4/16. 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.
Fri 5/297:41 pm
STL
- GEG
1 stop6h 18m
Alaska Airlines
Sun 5/318:20 am
GEG
- STL
1 stop6h 17m
Alaska Airlines
Deal found 4/16![Alaska Airlines logo]()
$471
This Delta deal was found by Cheapflights users on 4/14. 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 9/101:30 pm
STL
- JAC
1 stop7h 53m
Delta
Mon 9/145:30 pm
JAC
- STL
1 stop6h 06m
Delta
Deal found 4/14![Delta logo]()
$437
This Southwest deal was found by Cheapflights users on 4/14. 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 5/156:05 am
STL
- GEG
1 stop10h 05m
Southwest
Fri 5/222:50 pm
GEG
- STL
1 stop5h 15m
Southwest
Deal found 4/14![Southwest logo]()
$457
This United Airlines deal was found by Cheapflights users on 4/14. 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 5/234:45 pm
STL
- WYS
1 stop24h 17m
United Airlines
Sun 5/315:45 pm
WYS
- STL
1 stop5h 12m
United Airlines
Deal found 4/14![United Airlines logo]()
$563
This Alaska Airlines deal was found by Cheapflights users on 4/15. 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 8/25:37 pm
STL
- GEG
1 stop7h 22m
Alaska Airlines
Thu 8/135:00 am
GEG
- STL
1 stop9h 37m
Alaska Airlines
Deal found 4/15![Alaska Airlines logo]()
$471
This Delta deal was found by Cheapflights users on 4/14. 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 6/2710:16 am
STL
- JAC
2 stops12h 04m
Delta
Tue 7/76:06 pm
JAC
- STL
1 stop5h 31m
Delta
Deal found 4/14![Delta logo]()
$442
This Southwest deal was found by Cheapflights users on 4/13. 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 7/246:45 pm
STL
- BOI
1 stop8h 00m
Southwest
Mon 7/273:25 pm
BOI
- STL
2 stops7h 45m
Southwest
Deal found 4/13![Southwest logo]()
$457
This Delta deal was found by Cheapflights users on 4/14. 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 4/286:45 pm
STL
- IDA
1 stop4h 55m
Delta
Sat 5/25:47 am
IDA
- STL
2 stops7h 42m
Delta
Deal found 4/14![Delta logo]()
$444
This United Airlines deal was found by Cheapflights users on 4/16. 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 5/88:46 am
STL
- IDA
1 stop7h 57m
United Airlines
Sun 5/1010:40 am
IDA
- STL
1 stop5h 17m
United Airlines
Deal found 4/16![United Airlines logo]()
$610
This Southwest deal was found by Cheapflights users on 4/17. 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 6/85:35 am
STL
- GEG
2 stops8h 45m
Southwest
Fri 6/122:15 pm
GEG
- STL
2 stops8h 20m
Southwest
Deal found 4/17![Southwest logo]()
$467
This Delta deal was found by Cheapflights users on 4/17. 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 8/33:40 pm
STL
- BOI
1 stop7h 52m
Delta
Sat 8/810:29 am
BOI
- STL
1 stop5h 22m
Delta
Deal found 4/17![Delta logo]()
$445
This Southwest deal was found by Cheapflights users on 4/15. 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 7/184:45 pm
STL
- BOI
2 stops8h 10m
Southwest
Sat 7/256:00 pm
BOI
- STL
1 stop6h 00m
Southwest
Deal found 4/15![Southwest logo]()
$471
This Delta deal was found by Cheapflights users on 4/17. 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 9/162:15 pm
STL
- PIH
1 stop5h 10m
Delta
Tue 9/227:00 pm
PIH
- STL
1 stop4h 36m
Delta
Deal found 4/17![Delta logo]()
$447
Last-minute flights from St. Louis to IdahoDiscover last-minute flight deals from St. Louis to Idaho. Data last updated April 19, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Idaho. Data last updated April 19, 2026 and is based on user searches.
This Delta deal was found by Cheapflights users on 4/14. 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 4/296:20 am
STL
- JAC
2 stops10h 53m
Delta
Sun 5/37:20 am
JAC
- STL
1 stop5h 03m
Delta
Deal found 4/14![Delta logo]()
$364
This Kiwi.com deal was found by Cheapflights users on 4/14. 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
- GEG
1 stop27h 38m
Multiple Airlines
Sun 5/109:19 pm
GEG
- STL
2 stops20h 04m
Multiple Airlines
Deal found 4/14![Multiple Airlines logo]()
$302
This Trip.com deal was found by Cheapflights users on 4/17. 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 5/97:00 am
STL
- BOI
1 stop9h 33m
Alaska Airlines
Sat 5/164:19 pm
BOI
- STL
1 stop6h 35m
Alaska Airlines
Deal found 4/17![Alaska Airlines logo]()
$302
This Southwest deal was found by Cheapflights users on 4/17. 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 4/17![Southwest logo]()
$398
This Expedia deal was found by Cheapflights users on 4/15. 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.
Wed 5/135:33 pm
STL
- BOI
1 stop7h 25m
Alaska Airlines
Wed 5/204:19 pm
BOI
- STL
1 stop6h 35m
Alaska Airlines
Deal found 4/15![Alaska Airlines logo]()
$317
This Alaska Airlines deal was found by Cheapflights users on 4/14. 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.
Wed 5/135:33 pm
STL
- IDA
1 stop20h 44m
Alaska Airlines
Wed 5/206:00 am
IDA
- STL
1 stop8h 16m
Alaska Airlines
Deal found 4/14![Alaska Airlines logo]()
$339
This Delta deal was found by Cheapflights users on 4/16. 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 5/132:27 pm
STL
- JAC
1 stop8h 02m
Delta
Wed 5/207:00 am
JAC
- STL
1 stop6h 31m
Delta
Deal found 4/16![Delta logo]()
$359
This Southwest deal was found by Cheapflights users on 4/15. 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.
Wed 5/138:25 am
STL
- BOI
2 stops9h 00m
Southwest
Wed 5/202:00 pm
BOI
- STL
1 stop7h 00m
Southwest
Deal found 4/15![Southwest logo]()
$380
This Alaska Airlines deal was found by Cheapflights users on 4/16. 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.
Fri 5/155:33 pm
STL
- IDA
1 stop20h 44m
Alaska Airlines
Fri 5/224:03 pm
IDA
- STL
1 stop23h 34m
Alaska Airlines
Deal found 4/16![Alaska Airlines logo]()
$379
This American Airlines deal was found by Cheapflights users on 4/15. 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 5/197:05 am
STL
- GEG
1 stop7h 18m
American Airlines
Tue 5/262:08 pm
GEG
- STL
1 stop7h 46m
American Airlines
Deal found 4/15![American Airlines logo]()
$347
This American Airlines deal was found by Cheapflights users on 4/17. 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 5/267:00 am
STL
- BOI
1 stop8h 20m
American Airlines
Sat 5/303:11 pm
BOI
- STL
1 stop7h 43m
American Airlines
Deal found 4/17![American Airlines logo]()
$357
This American Airlines deal was found by Cheapflights users on 4/15. 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 5/305:25 am
STL
- BOI
1 stop6h 54m
American Airlines
Sat 6/63:11 pm
BOI
- STL
1 stop7h 45m
American Airlines
Deal found 4/15![American Airlines logo]()
$356
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 April 19, 2026.
Search for one-way flight options from St. Louis to Idaho. Find affordable one-way fares based on user searches. Data last updated April 19, 2026.
This CheapOair deal was found by Cheapflights users on 4/15. 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.
Sat 5/98:08 pm
STL
- BOI
1 stop17h 19m
Frontier
Deal found 4/15![Frontier logo]()
$92
This Kiwi.com deal was found by Cheapflights users on 4/14. 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.
Thu 5/78:08 pm
STL
- IDA
2 stops20h 19m
Multiple Airlines
Deal found 4/14![Multiple Airlines logo]()
$145
This CheapOair deal was found by Cheapflights users on 4/16. 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.
Sat 8/18:08 pm
STL
- BOI
1 stop17h 01m
Frontier
Deal found 4/16![Frontier logo]()
$157
This Kiwi.com deal was found by Cheapflights users on 4/15. 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.
Sat 5/98:08 pm
STL
- BOI
2 stops19h 15m
Multiple Airlines
Deal found 4/15![Multiple Airlines logo]()
$169
This American Airlines deal was found by Cheapflights users on 4/16. 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 5/125:51 am
STL
- GEG
1 stop8h 32m
American Airlines
Deal found 4/16![American Airlines logo]()
$174
This United Airlines deal was found by Cheapflights users on 4/16. 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 5/129:21 am
STL
- GEG
2 stops13h 55m
United Airlines
Deal found 4/16![United Airlines logo]()
$179
This Delta deal was found by Cheapflights users on 4/16. 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 5/77:59 pm
STL
- GEG
1 stop5h 36m
Delta
Deal found 4/16![Delta logo]()
$184
This Kiwi.com deal was found by Cheapflights users on 4/16. 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 5/126:33 pm
STL
- GEG
3 stops51h 56m
Multiple Airlines
Deal found 4/16![Multiple Airlines logo]()
$191
This American Airlines deal was found by Cheapflights users on 4/16. 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 8/197:23 am
STL
- BOI
1 stop6h 21m
American Airlines
Deal found 4/16![American Airlines logo]()
$192
This Southwest deal was found by Cheapflights users on 4/16. 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.
Wed 8/197:00 am
STL
- BOI
2 stops8h 00m
Southwest
Deal found 4/16![Southwest logo]()
$197
This CheapOair deal was found by Cheapflights users on 4/16. 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.
Sat 7/48:08 pm
STL
- BOI
1 stop17h 01m
Frontier
Deal found 4/16![Frontier logo]()
$201
This American Airlines deal was found by Cheapflights users on 4/16. 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 6/46:00 am
STL
- BOI
1 stop9h 20m
American Airlines
Deal found 4/16![American Airlines logo]()
$203
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 April 19, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $302 (Kiwi.com) |
One-way from | $92 (CheapOair) |
Popular in | February |
Cheapest in | January |
Average price | $396 |
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 April 19, 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
Wed 5/13
5:33 pm-1:17 pm
1 stop20h 44m
Idaho Falls Fanning Field
Wed 5/20
6:00 am-3:16 pm
1 stop8h 16m
$339
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 6/2
5:35 pm-11:30 pm
1 stop6h 55m
Boise Air Term. Gowen Fld
Tue 6/9
3:00 pm-11:40 pm
2 stops7h 40m
$362
St. LouisIdaho Falls
STL - IDA
STLIDA
Lambert-St Louis
Fri 5/15
5:33 pm-1:17 pm
1 stop20h 44m
Idaho Falls Fanning Field
Fri 5/22
4:03 pm-4:37 pm
1 stop23h 34m
$379
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Wed 6/3
8:53 am-4:59 pm
2 stops9h 06m
Jackson Hole
Sun 6/7
6:06 pm-12:39 am
1 stop5h 33m
$394
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Thu 7/30
6:30 am-4:59 pm
2 stops11h 29m
Jackson Hole
Wed 8/5
1:21 pm-11:53 pm
2 stops9h 32m
$399
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Wed 5/13
2:27 pm-9:29 pm
1 stop8h 02m
Jackson Hole
Wed 5/27
5:59 pm-12:30 am
1 stop5h 31m
$401
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Sun 9/27
1:30 pm-8:23 pm
1 stop7h 53m
Jackson Hole
Sat 10/3
5:30 pm-12:36 am
1 stop6h 06m
$409
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 6/30
5:20 pm-12:25 am
2 stops8h 05m
Boise Air Term. Gowen Fld
Tue 7/7
4:05 pm-11:55 pm
1 stop6h 50m
$412
St. LouisSpokane
STL - GEG
STLGEG
Lambert-St Louis
Sat 6/6
4:55 pm-11:20 pm
1 stop8h 25m
Spokane
Sun 6/14
6:40 pm-9:50 am
1 stop13h 10m
$417
St. LouisSpokane
STL - GEG
STLGEG
Lambert-St Louis
Thu 5/28
8:53 am-1:11 pm
1 stop6h 18m
Spokane
Sun 5/31
10:40 pm-8:18 am
1 stop7h 38m
$417
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, July is the cheapest month in which you can book a flight from St. Louis to Idaho (average of $104). Flying from St. Louis to Idaho in February is currently the most expensive (average of $553). 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 April 19, 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
Entertainment
7.5
Crew
8.6
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Comfort
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Comfort
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Comfort
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Overall
8.0
Comfort
8.0
Entertainment
7.5
Crew
8.6
Boarding
8.1
Food
7.0
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.
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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 April 19, 2026.
Popular flight searches
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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 April 19, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$163 | Average$373 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$186 | Average$366 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$290 | Average$461 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$296 | Average$442 | FlexibilityNo cancel fee | On-time63% |