$151+ Cheap flights from Idaho to St. Louis (STL)
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/17. Fares are subject to change and may not be available on all flights or dates of travel.
BOI — STL
Jul 11 — Jul 181
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
Find cheap flights from Idaho to St. Louis 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 Idaho to St. Louis
Cheapest
Best
Last-minute
One-way
Cheapest flights from Idaho to St. LouisExplore the most affordable flight options available from Idaho to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 11, 2026.
Explore the most affordable flight options available from Idaho to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 11, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/61:45 pm
TWF
- STL
1 stop27h 20m
Multiple Airlines
Sun 7/127:10 pm
STL
- TWF
1 stop17h 50m
Multiple Airlines
Deal found 6/10![Multiple Airlines logo]()
$256
This Delta deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 9/95:45 pm
BOI
- STL
1 stop5h 51m
Delta
Tue 9/156:25 am
STL
- BOI
1 stop8h 13m
Delta
Deal found 6/10![Delta logo]()
$263
This Southwest deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 9/93:40 pm
BOI
- STL
1 stop5h 55m
Southwest
Tue 9/157:00 am
STL
- BOI
2 stops7h 40m
Southwest
Deal found 6/9![Southwest logo]()
$270
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/292:20 pm
BOI
- STL
1 stop7h 25m
Southwest
Tue 10/68:35 am
STL
- BOI
2 stops8h 25m
Southwest
Deal found 6/8![Southwest logo]()
$279
This Frontier deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/21:25 pm
BOI
- STL
1 stop28h 28m
Frontier
Wed 7/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/6![Frontier logo]()
$289
This Travelocity deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Tue 8/47:56 pm
STL
- BOI
1 stop14h 41m
Multiple Airlines
Deal found 6/10![Multiple Airlines logo]()
$291
This CheapOair deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Sat 8/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/10![Frontier logo]()
$313
This United Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/12:30 pm
IDA
- STL
1 stop5h 13m
United Airlines
Thu 7/95:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Deal found 6/10![United Airlines logo]()
$319
This American Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 10/223:44 pm
GEG
- STL
1 stop6h 33m
American Airlines
Tue 10/275:40 am
STL
- GEG
1 stop8h 18m
American Airlines
Deal found 6/9![American Airlines logo]()
$331
This American Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 7/283:00 pm
GEG
- STL
1 stop6h 58m
American Airlines
Wed 8/56:00 am
STL
- GEG
1 stop9h 37m
American Airlines
Deal found 6/9![American Airlines logo]()
$341
This Delta deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/257:40 am
SUN
- STL
1 stop4h 58m
Delta
Fri 8/282:10 pm
STL
- SUN
2 stops8h 58m
Delta
Deal found 6/10![Delta logo]()
$356
This Gotogate deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/2612:31 pm
GEG
- STL
1 stop28h 22m
Frontier
Sun 6/287:38 pm
STL
- GEG
1 stop17h 58m
Frontier
Deal found 6/8![Frontier logo]()
$359
Best flights from Idaho to St. LouisDiscover carefully curated flight deals from Idaho to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 11, 2026.
Discover carefully curated flight deals from Idaho to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 11, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/61:45 pm
TWF
- STL
1 stop27h 20m
Multiple Airlines
Sun 7/127:10 pm
STL
- TWF
1 stop17h 50m
Multiple Airlines
Deal found 6/10![Multiple Airlines logo]()
$256
This United Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/12:30 pm
IDA
- STL
1 stop5h 13m
United Airlines
Thu 7/95:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Deal found 6/10![United Airlines logo]()
$319
This Delta deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/257:40 am
SUN
- STL
1 stop4h 58m
Delta
Fri 8/282:10 pm
STL
- SUN
2 stops8h 58m
Delta
Deal found 6/10![Delta logo]()
$356
This American Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 6/244:14 pm
JAC
- STL
1 stop6h 45m
American Airlines
Tue 7/146:55 am
STL
- JAC
2 stops9h 04m
American Airlines
Deal found 6/9![American Airlines logo]()
$364
This Alaska Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/36:02 am
GEG
- STL
1 stop6h 13m
Alaska Airlines
Wed 11/47:00 am
STL
- GEG
1 stop9h 22m
Alaska Airlines
Deal found 6/9![Alaska Airlines logo]()
$376
This Southwest deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” 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 8/64:55 pm
BOI
- STL
1 stop5h 55m
Southwest
Sun 8/96:15 am
STL
- BOI
1 stop6h 35m
Southwest
Deal found 6/8![Southwest logo]()
$415
This Delta deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/96:05 pm
JAC
- STL
1 stop5h 36m
Delta
Wed 7/152:30 pm
STL
- JAC
1 stop6h 07m
Delta
Deal found 6/10![Delta logo]()
$359
This United Airlines deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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 7/224:14 pm
IDA
- STL
1 stop6h 43m
United Airlines
Sun 7/265:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Deal found 6/7![United Airlines logo]()
$365
This Alaska Airlines deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/114:35 pm
BOI
- STL
1 stop6h 24m
Alaska Airlines
Tue 8/182:50 pm
STL
- BOI
1 stop7h 17m
Alaska Airlines
Deal found 6/7![Alaska Airlines logo]()
$407
This Delta deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/116:01 pm
JAC
- STL
1 stop5h 40m
Delta
Tue 8/183:50 pm
STL
- JAC
1 stop5h 20m
Delta
Deal found 6/6![Delta logo]()
$379
This Expedia deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Sat 8/88:00 am
STL
- BOI
2 stops11h 11m
Multiple Airlines
Deal found 6/9![Multiple Airlines logo]()
$422
This United Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 7/74:23 pm
JAC
- STL
1 stop6h 34m
United Airlines
Tue 7/144:48 pm
STL
- JAC
1 stop5h 10m
United Airlines
Deal found 6/9![United Airlines logo]()
$392
This Southwest deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/215:35 am
GEG
- STL
2 stops10h 40m
Southwest
Tue 7/283:10 pm
STL
- GEG
2 stops9h 10m
Southwest
Deal found 6/10![Southwest logo]()
$435
This Alaska Airlines deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” 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 9/16:23 am
BOI
- STL
1 stop6h 43m
Alaska Airlines
Wed 9/26:08 pm
STL
- BOI
1 stop6h 47m
Alaska Airlines
Deal found 6/6![Alaska Airlines logo]()
$407
This American Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/103:10 pm
BOI
- STL
1 stop8h 06m
American Airlines
Thu 7/166:55 am
STL
- BOI
1 stop8h 25m
American Airlines
Deal found 6/10![American Airlines logo]()
$467
This United Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 9/15:00 am
BOI
- STL
2 stops9h 38m
United Airlines
Wed 9/28:42 am
STL
- BOI
1 stop7h 49m
United Airlines
Deal found 6/9![United Airlines logo]()
$398
This Alaska Airlines deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” 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 9/226:18 am
IDA
- STL
1 stop7h 03m
Alaska Airlines
Sat 9/263:19 pm
STL
- IDA
1 stop8h 37m
Alaska Airlines
Deal found 6/5![Alaska Airlines logo]()
$419
This Southwest deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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 7/305:55 pm
BOI
- STL
1 stop7h 00m
Southwest
Sat 8/87:10 am
STL
- BOI
1 stop6h 05m
Southwest
Deal found 6/7![Southwest logo]()
$467
This Delta deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” 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 8/106:01 pm
JAC
- STL
1 stop5h 40m
Delta
Mon 8/178:00 am
STL
- JAC
1 stop5h 15m
Delta
Deal found 6/6![Delta logo]()
$431
This Alaska Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 8/296:18 am
IDA
- STL
1 stop6h 48m
Alaska Airlines
Tue 9/13:04 pm
STL
- IDA
1 stop8h 52m
Alaska Airlines
Deal found 6/9![Alaska Airlines logo]()
$419
This Southwest deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/273:25 pm
BOI
- STL
2 stops7h 50m
Southwest
Sat 8/87:10 am
STL
- BOI
1 stop6h 05m
Southwest
Deal found 6/10![Southwest logo]()
$468
This United Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/12:38 pm
SUN
- STL
1 stop5h 05m
United Airlines
Sat 7/49:11 am
STL
- SUN
2 stops13h 50m
United Airlines
Deal found 6/10![United Airlines logo]()
$435
This Delta deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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 7/167:00 pm
PIH
- STL
1 stop4h 41m
Delta
Mon 7/202:30 pm
STL
- PIH
1 stop4h 53m
Delta
Deal found 6/7![Delta logo]()
$467
This Southwest deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” 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 7/210:25 am
BOI
- STL
2 stops7h 45m
Southwest
Wed 7/86:20 pm
STL
- BOI
1 stop7h 15m
Southwest
Deal found 6/6![Southwest logo]()
$472
This United Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 10/312:29 pm
SUN
- STL
1 stop5h 30m
United Airlines
Tue 11/39:13 am
STL
- SUN
1 stop5h 31m
United Airlines
Deal found 6/10![United Airlines logo]()
$441
This Alaska Airlines deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/37:41 pm
GEG
- STL
1 stop18h 56m
Alaska Airlines
Thu 8/66:02 am
STL
- GEG
1 stop6h 58m
Alaska Airlines
Deal found 6/5![Alaska Airlines logo]()
$450
This Southwest deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/206:30 am
GEG
- STL
2 stops9h 55m
Southwest
Mon 8/243:45 pm
STL
- GEG
2 stops8h 15m
Southwest
Deal found 6/7![Southwest logo]()
$477
This United Airlines deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/261:45 pm
JAC
- STL
1 stop6h 01m
United Airlines
Sat 8/294:40 pm
STL
- JAC
1 stop5h 00m
United Airlines
Deal found 6/8![United Airlines logo]()
$479
This Delta deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” 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 7/33:25 pm
TWF
- STL
2 stops6h 58m
Delta
Sat 7/45:00 pm
STL
- TWF
1 stop6h 17m
Delta
Deal found 6/6![Delta logo]()
$542
This Southwest deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 7/22:15 pm
GEG
- STL
2 stops8h 20m
Southwest
Mon 7/65:30 pm
STL
- GEG
2 stops9h 05m
Southwest
Deal found 6/9![Southwest logo]()
$511
Last-minute flights from Idaho to St. LouisDiscover last-minute flight deals from Idaho to St. Louis. Data last updated June 11, 2026 and is based on user searches.
Discover last-minute flight deals from Idaho to St. Louis. Data last updated June 11, 2026 and is based on user searches.
This Delta deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 6/246:05 pm
JAC
- STL
1 stop5h 38m
Delta
Tue 7/142:30 pm
STL
- JAC
1 stop6h 07m
Delta
Deal found 6/9![Delta logo]()
$359
This American Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 6/244:14 pm
JAC
- STL
1 stop6h 45m
American Airlines
Tue 7/146:55 am
STL
- JAC
2 stops9h 04m
American Airlines
Deal found 6/9![American Airlines logo]()
$364
This Gotogate deal was found by Cheapflights users on 6/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/2612:31 pm
GEG
- STL
1 stop28h 22m
Frontier
Sun 6/287:38 pm
STL
- GEG
1 stop17h 58m
Frontier
Deal found 6/8![Frontier logo]()
$359
This United Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/12:30 pm
IDA
- STL
1 stop5h 13m
United Airlines
Thu 7/95:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Deal found 6/10![United Airlines logo]()
$319
This Frontier deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/21:25 pm
BOI
- STL
1 stop28h 28m
Frontier
Wed 7/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/6![Frontier logo]()
$289
This Delta deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/35:10 pm
GEG
- STL
1 stop5h 33m
Delta
Tue 7/77:55 pm
STL
- GEG
1 stop6h 00m
Delta
Deal found 6/10![Delta logo]()
$383
This Booking.com deal was found by Cheapflights users on 6/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/46:23 am
BOI
- STL
1 stop6h 29m
Multiple Airlines
Sat 7/118:08 pm
STL
- BOI
1 stop17h 21m
Multiple Airlines
Deal found 6/6![Multiple Airlines logo]()
$365
This Kiwi.com deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/61:45 pm
TWF
- STL
1 stop27h 20m
Multiple Airlines
Sun 7/127:10 pm
STL
- TWF
1 stop17h 50m
Multiple Airlines
Deal found 6/10![Multiple Airlines logo]()
$256
This United Airlines deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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 7/224:14 pm
IDA
- STL
1 stop6h 43m
United Airlines
Sun 7/265:10 am
STL
- IDA
1 stop5h 40m
United Airlines
Deal found 6/7![United Airlines logo]()
$365
This American Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 7/283:00 pm
GEG
- STL
1 stop6h 58m
American Airlines
Wed 8/56:00 am
STL
- GEG
1 stop9h 37m
American Airlines
Deal found 6/9![American Airlines logo]()
$341
This Travelocity deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Multiple Airlines
Tue 8/47:56 pm
STL
- BOI
1 stop14h 41m
Multiple Airlines
Deal found 6/10![Multiple Airlines logo]()
$291
This CheapOair deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Sat 8/88:08 pm
STL
- BOI
1 stop17h 21m
Frontier
Deal found 6/10![Frontier logo]()
$313
One-way flights from Idaho to St. LouisSearch for one-way flight options from Idaho to St. Louis. Find affordable one-way fares based on user searches. Data last updated June 11, 2026.
Search for one-way flight options from Idaho to St. Louis. Find affordable one-way fares based on user searches. Data last updated June 11, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/1710:54 pm
IDA
- STL
1 stop18h 14m
Multiple Airlines
Deal found 6/7![Multiple Airlines logo]()
$151
This Expedia deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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.
Thu 7/301:24 pm
BOI
- STL
1 stop4h 59m
Frontier
Deal found 6/7![Frontier logo]()
$154
This Kiwi.com deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/268:51 pm
GEG
- STL
1 stop19h 24m
Multiple Airlines
Deal found 6/10![Multiple Airlines logo]()
$154
This Delta deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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 7/157:00 pm
IDA
- STL
1 stop4h 41m
Delta
Deal found 6/7![Delta logo]()
$160
This American Airlines deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” 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 7/41:59 pm
GEG
- STL
1 stop8h 16m
American Airlines
Deal found 6/9![American Airlines logo]()
$192
This Southwest deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/294:20 pm
BOI
- STL
1 stop6h 15m
Southwest
Deal found 6/10![Southwest logo]()
$202
This Delta deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/116:01 pm
JAC
- STL
1 stop5h 40m
Delta
Deal found 6/9![Delta logo]()
$210
This Priceline deal was found by Cheapflights users on 6/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/126:18 am
IDA
- STL
1 stop7h 03m
Alaska Airlines
Deal found 6/9![Alaska Airlines logo]()
$210
This Southwest deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/181:50 pm
GEG
- STL
1 stop7h 20m
Southwest
Deal found 6/7![Southwest logo]()
$213
This Delta deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/117:00 am
GEG
- STL
1 stop6h 13m
Delta
Deal found 6/10![Delta logo]()
$234
This Southwest deal was found by Cheapflights users on 6/7. Clicking the “Pick Dates” 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 7/304:25 pm
BOI
- STL
2 stops7h 15m
Southwest
Deal found 6/7![Southwest logo]()
$239
This American Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” 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 7/106:30 am
GEG
- STL
2 stops10h 00m
American Airlines
Deal found 6/10![American Airlines logo]()
$239
Find flight deals from Idaho to St. Louis
Keep the following information in mind while searching for Idaho to St. Louis flight deals. Data was last updated June 11, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $256 (Kiwi.com) |
One-way from | $151 (Kiwi.com) |
Popular in | November |
Cheapest in | September |
Average price | $500 |
Cheapflights Fare Finder
Customize your flight search to find flights from Idaho to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 11, 2026.
Use the filters below to find and compare flights from Idaho to St. Louis that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
Twin FallsSt. Louis
TWF - STL
TWFSTL
Twin Falls Joslin
Mon 7/6
1:45 pm-6:05 pm
1 stop27h 20m
Lambert-St Louis
Sun 7/12
7:10 pm-12:00 pm
1 stop17h 50m
$256
Idaho FallsSt. Louis
IDA - STL
IDASTL
Idaho Falls Fanning Field
Wed 7/1
2:30 pm-8:43 pm
1 stop5h 13m
Lambert-St Louis
Thu 7/9
5:10 am-9:50 am
1 stop5h 40m
$319
HaileySt. Louis
SUN - STL
SUNSTL
Hailey Sun Valley-Friedman
Tue 8/25
7:40 am-1:38 pm
1 stop4h 58m
Lambert-St Louis
Fri 8/28
2:10 pm-10:08 pm
2 stops8h 58m
$356
JacksonSt. Louis
JAC - STL
JACSTL
Jackson Hole
Thu 7/9
6:05 pm-12:41 am
1 stop5h 36m
Lambert-St Louis
Wed 7/15
2:30 pm-7:37 pm
1 stop6h 07m
$359
JacksonSt. Louis
JAC - STL
JACSTL
Jackson Hole
Wed 6/24
4:14 pm-11:59 pm
1 stop6h 45m
Lambert-St Louis
Tue 7/14
6:55 am-2:59 pm
2 stops9h 04m
$364
Idaho FallsSt. Louis
IDA - STL
IDASTL
Idaho Falls Fanning Field
Wed 7/22
4:14 pm-11:57 pm
1 stop6h 43m
Lambert-St Louis
Sun 7/26
5:10 am-9:50 am
1 stop5h 40m
$365
SpokaneSt. Louis
GEG - STL
GEGSTL
Spokane
Tue 11/3
6:02 am-2:15 pm
1 stop6h 13m
Lambert-St Louis
Wed 11/4
7:00 am-2:22 pm
1 stop9h 22m
$376
JacksonSt. Louis
JAC - STL
JACSTL
Jackson Hole
Tue 8/11
6:01 pm-12:41 am
1 stop5h 40m
Lambert-St Louis
Tue 8/18
3:50 pm-8:10 pm
1 stop5h 20m
$379
JacksonSt. Louis
JAC - STL
JACSTL
Jackson Hole
Tue 7/7
4:23 pm-11:57 pm
1 stop6h 34m
Lambert-St Louis
Tue 7/14
4:48 pm-8:58 pm
1 stop5h 10m
$392
BoiseSt. Louis
BOI - STL
BOISTL
Boise Air Term. Gowen Fld
Tue 9/1
5:00 am-3:38 pm
2 stops9h 38m
Lambert-St Louis
Wed 9/2
8:42 am-3:31 pm
1 stop7h 49m
$398
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Idaho to St. Louis
Have a flexible travel schedule? Discover the best time to fly to St. Louis from Idaho with our price prediction graph.
BOI-STL
IDA-STL
GEG-STL
JAC-STL
SUN-STL
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 Idaho to St. Louis
USID-STL
BOI-STL
IDA-STL
GEG-STL
JAC-STL
What is the cheapest month to book a flight from Idaho to St. Louis?
Currently, November is the cheapest month in which you can book a flight from Idaho to St. Louis (average of $185). Flying from Idaho to St. Louis in June is currently the most expensive (average of $388). 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 Idaho to St. Louis?
Related info for your journey
Find useful and relevant information for your journey from Idaho to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near St. Louis?
Book flights to St. Louis if you plan to visit one of these locationsEdwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Eureka
Maryland Heights
Collinsville
Wentzville
Glencoe
Chesterfield
Alton
Farmington
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
St. Louis flight routes
Top destinations
Alternative routes for Idaho to St. Louis
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to St. Louis by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Idaho to St. Louis by cabin class
Find flights from Idaho to St. Louis, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Idaho and St. Louis flights
Browse other Idaho and St. Louis flight options. Last updated on June 11, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Other flights to St. Louis
Explore flights to St. Louis departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on June 11, 2026.
Idaho to St. Louis flights
Consider these flights traveling from Idaho to St. Louis.
Top 4 airlines flying from Idaho to St. Louis
Discover the top 4 airlines that operate flights from Idaho to St. Louis. 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 June 11, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$185 | Average$491 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$281 | Average$486 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$283 | Average$483 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$350 | Average$430 | FlexibilityNo cancel fee | On-time71% |