$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 29 — May 61
Round-trip
1 adult, Economy
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Find cheap flights from St. Louis to Idaho with Cheapflights
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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 March 30, 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 30, 2026.
This CheapOair deal was found by Cheapflights users on 3/29. 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 6/248:08 pm
STL
- BOI
1 stop17h 01m
Frontier
Tue 6/301:04 pm
BOI
- STL
1 stop5h 19m
Frontier
Deal found 3/29![Frontier logo]()
$241
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 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 Alaska Airlines deal was found by Cheapflights users on 3/29. 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 5/27:00 am
STL
- BOI
1 stop9h 33m
Alaska Airlines
Tue 5/54:38 pm
BOI
- STL
1 stop6h 21m
Alaska Airlines
Deal found 3/29![Alaska Airlines 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 American Airlines deal was found by Cheapflights users on 3/28. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/255:20 am
STL
- BOI
1 stop8h 43m
American Airlines
Sat 5/21:29 pm
BOI
- STL
1 stop7h 48m
American Airlines
Deal found 3/28![American Airlines logo]()
$321
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 Southwest deal was found by Cheapflights users on 3/28. 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 4/256:10 am
STL
- BOI
2 stops11h 05m
Southwest
Sat 5/211:00 am
BOI
- STL
2 stops8h 20m
Southwest
Deal found 3/28![Southwest logo]()
$333
This Delta deal was found by Cheapflights users on 3/29. 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 8/247:30 am
STL
- WYS
1 stop5h 51m
Delta
Sat 8/2911:29 am
WYS
- STL
2 stops11h 08m
Delta
Deal found 3/29![Delta logo]()
$334
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
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 30, 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 30, 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 Alaska Airlines deal was found by Cheapflights users on 3/28. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/27:00 am
STL
- BOI
1 stop9h 33m
Alaska Airlines
Tue 5/52:57 pm
BOI
- STL
1 stop8h 02m
Alaska Airlines
Deal found 3/28![Alaska Airlines logo]()
$317
This American Airlines deal was found by Cheapflights users on 3/28. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/255:20 am
STL
- BOI
1 stop8h 43m
American Airlines
Sat 5/21:29 pm
BOI
- STL
1 stop7h 48m
American Airlines
Deal found 3/28![American Airlines logo]()
$321
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.
Fri 4/107:45 am
STL
- JAC
2 stops8h 39m
United Airlines
Tue 4/142:35 pm
JAC
- STL
1 stop5h 19m
United Airlines
Deal found 3/26![United Airlines logo]()
$364
This Delta deal was found by Cheapflights users on 3/28. 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 5/56:45 pm
STL
- IDA
1 stop4h 55m
Delta
Fri 5/86:54 pm
IDA
- STL
2 stops13h 55m
Delta
Deal found 3/28![Delta logo]()
$359
This Southwest deal was found by Cheapflights users on 3/29. 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 4/275:15 pm
STL
- BOI
1 stop7h 15m
Southwest
Wed 5/62:00 pm
BOI
- STL
1 stop7h 00m
Southwest
Deal found 3/29![Southwest logo]()
$361
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 4/257:45 am
STL
- JAC
2 stops8h 39m
United Airlines
Fri 5/12:30 pm
JAC
- STL
1 stop5h 13m
United Airlines
Deal found 3/25![United Airlines logo]()
$364
This Southwest deal was found by Cheapflights users on 3/28. 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 4/256:10 am
STL
- BOI
2 stops11h 05m
Southwest
Sat 5/22:50 pm
BOI
- STL
1 stop5h 25m
Southwest
Deal found 3/28![Southwest logo]()
$388
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 4/289:10 am
STL
- BOI
2 stops14h 25m
United Airlines
Sat 5/212:30 pm
BOI
- STL
2 stops9h 49m
United Airlines
Deal found 3/26![United Airlines logo]()
$390
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 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.
Wed 4/226:35 am
STL
- GEG
2 stops9h 10m
Southwest
Sat 4/2510:45 am
GEG
- STL
2 stops7h 35m
Southwest
Deal found 3/25![Southwest logo]()
$395
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 5/94:46 pm
STL
- GEG
1 stop6h 45m
Alaska Airlines
Wed 5/131:59 pm
GEG
- STL
1 stop7h 55m
Alaska Airlines
Deal found 3/25![Alaska Airlines logo]()
$488
This United Airlines deal was found by Cheapflights users on 3/28. 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.
Sun 5/315:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Tue 6/25:54 pm
IDA
- STL
1 stop5h 03m
United Airlines
Deal found 3/28![United Airlines logo]()
$429
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.
Mon 4/136:45 pm
STL
- GEG
1 stop6h 49m
Delta
Fri 4/177:38 pm
GEG
- STL
2 stops12h 10m
Delta
Deal found 3/25![Delta logo]()
$449
This United Airlines deal was found by Cheapflights users on 3/28. 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.
Sat 5/210:25 am
STL
- IDA
2 stops11h 38m
United Airlines
Mon 5/42:31 pm
IDA
- STL
1 stop5h 12m
United Airlines
Deal found 3/28![United Airlines logo]()
$448
This Delta deal was found by Cheapflights users on 3/30. 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 4/212:04 pm
STL
- IDA
2 stops11h 12m
Delta
Tue 4/76:55 pm
IDA
- STL
1 stop4h 26m
Delta
Deal found 3/30![Delta logo]()
$474
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.
Thu 6/185:35 am
STL
- GEG
2 stops8h 45m
Southwest
Wed 6/242:55 pm
GEG
- STL
1 stop7h 00m
Southwest
Deal found 3/27![Southwest logo]()
$496
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 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.
Sat 4/115:29 pm
STL
- GEG
1 stop6h 00m
Delta
Wed 4/155:10 pm
GEG
- STL
1 stop5h 15m
Delta
Deal found 3/26![Delta logo]()
$479
This Delta deal was found by Cheapflights users on 3/30. 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 4/26:12 pm
STL
- IDA
1 stop5h 04m
Delta
Mon 4/66:55 pm
IDA
- STL
1 stop4h 26m
Delta
Deal found 3/30![Delta logo]()
$489
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 3/25. 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.
Sun 6/288:00 am
STL
- GEG
1 stop6h 15m
Delta
Fri 7/1010:48 pm
GEG
- STL
1 stop8h 18m
Delta
Deal found 3/25![Delta logo]()
$498
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.
Sat 5/99:00 am
STL
- GEG
2 stops14h 16m
United Airlines
Wed 5/135:00 am
GEG
- STL
1 stop6h 13m
United Airlines
Deal found 3/26![United Airlines logo]()
$501
This United Airlines deal was found by Cheapflights users on 3/28. 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.
Mon 6/15:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Tue 6/25:54 pm
IDA
- STL
1 stop5h 03m
United Airlines
Deal found 3/28![United Airlines logo]()
$505
This Delta deal was found by Cheapflights users on 3/29. 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 5/153:11 pm
STL
- JAC
1 stop6h 04m
Delta
Thu 5/215:59 pm
JAC
- STL
1 stop5h 31m
Delta
Deal found 3/29![Delta logo]()
$505
This United Airlines deal was found by Cheapflights users on 3/28. 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.
Mon 6/15:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Wed 6/35:54 pm
IDA
- STL
1 stop5h 03m
United Airlines
Deal found 3/28![United Airlines logo]()
$505
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 5/146:45 am
STL
- GEG
2 stops12h 12m
Delta
Mon 5/187:23 pm
GEG
- STL
2 stops11h 23m
Delta
Deal found 3/26![Delta logo]()
$506
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.
Mon 5/111:59 pm
STL
- GEG
2 stops10h 52m
Delta
Mon 5/187:23 pm
GEG
- STL
2 stops11h 23m
Delta
Deal found 3/26![Delta logo]()
$506
This United Airlines deal was found by Cheapflights users on 3/29. 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 4/211:15 am
STL
- JAC
2 stops10h 38m
United Airlines
Sat 4/42:35 pm
JAC
- STL
1 stop5h 19m
United Airlines
Deal found 3/29![United Airlines logo]()
$574
Last-minute flights from St. Louis to IdahoDiscover last-minute flight deals from St. Louis to Idaho. Data last updated March 30, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Idaho. Data last updated March 30, 2026 and is based on user searches.
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.
Fri 4/102:40 pm
STL
- JAC
1 stop7h 13m
United Airlines
Tue 4/142:35 pm
JAC
- STL
1 stop5h 19m
United Airlines
Deal found 3/26![United Airlines logo]()
$359
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 3/26. 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.
Fri 4/176:00 am
STL
- BOI
1 stop8h 07m
Delta
Mon 4/273:23 pm
BOI
- STL
1 stop6h 50m
Delta
Deal found 3/26![Delta logo]()
$344
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 American Airlines deal was found by Cheapflights users on 3/28. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/255:20 am
STL
- BOI
1 stop8h 43m
American Airlines
Sat 5/21:29 pm
BOI
- STL
1 stop7h 48m
American Airlines
Deal found 3/28![American Airlines logo]()
$321
This Southwest deal was found by Cheapflights users on 3/28. 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 4/256:10 am
STL
- BOI
2 stops11h 05m
Southwest
Sat 5/211:00 am
BOI
- STL
2 stops8h 20m
Southwest
Deal found 3/28![Southwest logo]()
$333
This Southwest deal was found by Cheapflights users on 3/29. 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 4/275:15 pm
STL
- BOI
1 stop7h 15m
Southwest
Wed 5/62:00 pm
BOI
- STL
1 stop7h 00m
Southwest
Deal found 3/29![Southwest logo]()
$361
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
This Alaska 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/304:46 pm
STL
- GEG
1 stop8h 25m
Alaska Airlines
Sat 5/22:45 pm
GEG
- STL
1 stop7h 14m
Alaska Airlines
Deal found 3/27![Alaska Airlines logo]()
$361
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 30, 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 30, 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 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 3/28. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/255:51 am
STL
- GEG
1 stop8h 41m
American Airlines
Deal found 3/28![American Airlines logo]()
$159
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 United Airlines deal was found by Cheapflights users on 3/28. 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.
Sat 4/257:45 am
STL
- GEG
2 stops9h 30m
United Airlines
Deal found 3/28![United Airlines logo]()
$164
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 Kiwi.com deal was found by Cheapflights users on 3/28. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/1712:16 pm
STL
- GEG
1 stop10h 13m
Multiple Airlines
Deal found 3/28![Multiple Airlines logo]()
$193
This Alaska 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/165:33 pm
STL
- GEG
1 stop16h 55m
Alaska Airlines
Deal found 3/27![Alaska Airlines logo]()
$199
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/167:08 pm
STL
- GEG
2 stops27h 21m
Multiple Airlines
Deal found 3/27![Multiple Airlines logo]()
$200
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 Kiwi.com deal was found by Cheapflights users on 3/30. 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 4/144:59 pm
STL
- BOI
2 stops43h 09m
Frontier
Deal found 3/30![Frontier logo]()
$225
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 30, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $241 (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 30, 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 5/2
7:00 am-3:33 pm
1 stop9h 33m
Boise Air Term. Gowen Fld
Tue 5/5
2:57 pm-11:59 pm
1 stop8h 02m
$317
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Sat 4/25
5:20 am-1:03 pm
1 stop8h 43m
Boise Air Term. Gowen Fld
Sat 5/2
1:29 pm-10:17 pm
1 stop7h 48m
$321
St. LouisIdaho Falls
STL - IDA
STLIDA
Lambert-St Louis
Tue 5/5
6:45 pm-10:40 pm
1 stop4h 55m
Idaho Falls Fanning Field
Fri 5/8
6:54 pm-9:49 am
2 stops13h 55m
$359
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Mon 4/27
5:15 pm-11:30 pm
1 stop7h 15m
Boise Air Term. Gowen Fld
Wed 5/6
2:00 pm-10:00 pm
1 stop7h 00m
$361
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Fri 4/10
7:45 am-3:24 pm
2 stops8h 39m
Jackson Hole
Tue 4/14
2:35 pm-8:54 pm
1 stop5h 19m
$364
St. LouisJackson
STL - JAC
STLJAC
Lambert-St Louis
Sat 4/25
7:45 am-3:24 pm
2 stops8h 39m
Jackson Hole
Fri 5/1
2:30 pm-8:43 pm
1 stop5h 13m
$364
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Sat 4/25
6:10 am-4:15 pm
2 stops11h 05m
Boise Air Term. Gowen Fld
Sat 5/2
2:50 pm-9:15 pm
1 stop5h 25m
$388
St. LouisBoise
STL - BOI
STLBOI
Lambert-St Louis
Tue 4/28
9:10 am-10:35 pm
2 stops14h 25m
Boise Air Term. Gowen Fld
Sat 5/2
12:30 pm-11:19 pm
2 stops9h 49m
$390
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-JAC
STL-IDA
STL-GEG
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-JAC
STL-IDA
STL-GEG
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 30, 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
Boarding
8.1
Crew
8.6
Overall
8.0
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreDominic,Mar 2026
MCO - SMF
Food
7.0
Boarding
8.1
Crew
8.6
Overall
8.0
Comfort
8.0
Entertainment
7.5
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 March 30, 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 30, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$163 | Average$375 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$186 | Average$366 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$290 | Average$468 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$296 | Average$421 | FlexibilityNo cancel fee | On-time63% |