$180+ Cheap flights from St. Louis to Idaho Falls (STL - IDA)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/13. Fares are subject to change and may not be available on all flights or dates of travel.
STL — IDA
Oct 14 — Oct 211
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
Find cheap flights from St. Louis to Idaho Falls with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from St. Louis to Idaho Falls
Cheapest
Best
Last-minute
One-way
Cheapest flights from St. Louis to Idaho FallsExplore the most affordable flight options available from St. Louis to Idaho Falls. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 14, 2026.
Explore the most affordable flight options available from St. Louis to Idaho Falls. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 14, 2026.
This United Airlines deal was found by Cheapflights users on 9/13. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/149:00 am -
1 stop5h 24m
Mon 10/194:05 pm -
1 stop6h 39m
Deal found 9/13![United Airlines logo]()
$422
This American Airlines deal was found by Cheapflights users on 9/12. Clicking the “Pick Dates” 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 10/15:43 am -
1 stop7h 02m
Mon 10/51:50 pm -
1 stop6h 07m
Deal found 9/12![American Airlines logo]()
$454
This Alaska Airlines deal was found by Cheapflights users on 9/13. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/283:19 pm -
1 stop8h 37m
Fri 10/22:01 pm -
1 stop8h 58m
Deal found 9/13![Alaska Airlines logo]()
$459
This United Airlines deal was found by Cheapflights users on 9/13. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/15:10 am -
1 stop5h 43m
Mon 10/55:51 pm -
1 stop4h 53m
Deal found 9/13![United Airlines logo]()
$464
This Kiwi.com deal was found by Cheapflights users on 9/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2412:27 pm -
1 stop24h 31m
Mon 9/286:21 pm -
1 stop16h 11m
Deal found 9/9![Multiple Airlines logo]()
$489
This Delta deal was found by Cheapflights users on 9/13. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/11:55 pm -
2 stops9h 27m
Mon 10/56:57 pm -
1 stop4h 47m
Deal found 9/13![Delta logo]()
$502
This American Airlines deal was found by Cheapflights users on 9/10. 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.
Thu 9/175:43 am -
1 stop7h 02m
Mon 9/212:08 pm -
1 stop8h 35m
Deal found 9/10![American Airlines logo]()
$518
Best flights from St. Louis to Idaho FallsDiscover carefully curated flight deals from St. Louis to Idaho Falls that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 14, 2026.
Discover carefully curated flight deals from St. Louis to Idaho Falls that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 14, 2026.
This United Airlines deal was found by Cheapflights users on 9/10. 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 2/63:00 pm -
1 stop7h 08m
Tue 2/92:35 pm -
1 stop5h 24m
Deal found 9/10![United Airlines logo]()
$419
This Alaska Airlines deal was found by Cheapflights users on 9/13. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/283:19 pm -
1 stop8h 37m
Fri 10/22:01 pm -
1 stop8h 58m
Deal found 9/13![Alaska Airlines logo]()
$459
This United Airlines deal was found by Cheapflights users on 9/13. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/149:00 am -
1 stop5h 24m
Mon 10/194:05 pm -
1 stop6h 39m
Deal found 9/13![United Airlines logo]()
$422
Last-minute flights from St. Louis to Idaho FallsDiscover last-minute flight deals from St. Louis to Idaho Falls. Data last updated September 14, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Idaho Falls. Data last updated September 14, 2026 and is based on user searches.
This American Airlines deal was found by Cheapflights users on 9/10. 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.
Thu 9/175:43 am -
1 stop7h 02m
Mon 9/212:08 pm -
1 stop8h 35m
Deal found 9/10![American Airlines logo]()
$518
This Kiwi.com deal was found by Cheapflights users on 9/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/2412:27 pm -
1 stop24h 31m
Mon 9/286:21 pm -
1 stop16h 11m
Deal found 9/9![Multiple Airlines logo]()
$489
This Alaska Airlines deal was found by Cheapflights users on 9/13. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/283:19 pm -
1 stop8h 37m
Fri 10/22:01 pm -
1 stop8h 58m
Deal found 9/13![Alaska Airlines logo]()
$459
This American Airlines deal was found by Cheapflights users on 9/12. Clicking the “Pick Dates” 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 10/15:43 am -
1 stop7h 02m
Mon 10/51:50 pm -
1 stop6h 07m
Deal found 9/12![American Airlines logo]()
$454
This United Airlines deal was found by Cheapflights users on 9/13. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/15:10 am -
1 stop5h 43m
Mon 10/55:51 pm -
1 stop4h 53m
Deal found 9/13![United Airlines logo]()
$464
This Delta deal was found by Cheapflights users on 9/13. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/11:55 pm -
2 stops9h 27m
Mon 10/56:57 pm -
1 stop4h 47m
Deal found 9/13![Delta logo]()
$502
This United Airlines deal was found by Cheapflights users on 9/13. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/149:00 am -
1 stop5h 24m
Mon 10/194:05 pm -
1 stop6h 39m
Deal found 9/13![United Airlines logo]()
$422
One-way flights from St. Louis to Idaho FallsSearch for one-way flight options from St. Louis to Idaho Falls. Find affordable one-way fares based on user searches. Data last updated September 14, 2026.
Search for one-way flight options from St. Louis to Idaho Falls. Find affordable one-way fares based on user searches. Data last updated September 14, 2026.
This Delta deal was found by Cheapflights users on 9/10. 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 10/132:25 pm -
2 stops8h 45m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Delta logo]()
$180
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Wed 10/144:19 pm -
3 stops48h 41m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Multiple Airlines logo]()
$219
This United Airlines deal was found by Cheapflights users on 9/10. 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 10/145:10 am -
1 stop5h 43m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![United Airlines logo]()
$220
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Thu 10/155:53 pm -
2 stops23h 07m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Multiple Airlines logo]()
$250
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Tue 10/133:35 pm -
3 stops32h 24m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Multiple Airlines logo]()
$583
Find flight deals from St. Louis to Idaho Falls
Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Idaho Falls (IDA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 14, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $419 (United Airlines) |
One-way from | $180 (Delta) |
Popular in | November |
Cheapest in | September |
Average price | $434 |
Cheapflights Fare Finder
Customize your flight search to find flights from St. Louis to Idaho Falls 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 7,457,451 searches. Data last updated September 14, 2026.
Use the filters below to find and compare flights from St. Louis to Idaho Falls that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Tue 10/13
2:25 pm-10:10 pm
2 stops8h 45m
Idaho Falls Fanning Field
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$180
Quickest round-trip
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Thu 10/15
5:10 am-9:53 am
1 stop5h 43m
Idaho Falls Fanning Field
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$220
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Wed 10/14
6:35 pm-4:00 pm
2 stops46h 25m
Idaho Falls Fanning Field
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$251
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Sat 2/6
3:00 pm-9:08 pm
1 stop7h 08m
Idaho Falls Fanning Field
Tue 2/9
2:35 pm-8:59 pm
1 stop5h 24m
$419
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Wed 10/14
9:00 am-1:24 pm
1 stop5h 24m
Idaho Falls Fanning Field
Mon 10/19
4:05 pm-11:44 pm
1 stop6h 39m
$422
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Mon 9/28
3:19 pm-10:56 pm
1 stop8h 37m
Idaho Falls Fanning Field
Fri 10/2
2:01 pm-11:59 pm
1 stop8h 58m
$459
St. LouisIdaho Falls
STL Lambert-St Louis - IDA Idaho Falls Fanning Field
STLIDA
Lambert-St Louis
Tue 10/13
3:35 pm-10:59 pm
3 stops32h 24m
Idaho Falls Fanning Field
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$583
Sorted by cheapest first
Compare providers for flights from St. Louis to Idaho Falls
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Idaho Falls in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on St. Louis-Idaho Falls flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Idaho Falls flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Idaho Falls flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on St. Louis-Idaho Falls flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Idaho Falls flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from St. Louis to Idaho Falls
Have a flexible travel schedule? Discover the best time to fly to Idaho Falls from St. Louis with our price prediction graph.
STL-IDA
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 Falls
Reviews of airlines servicing Idaho Falls
Get insights into the airlines that provide service to Idaho Falls. 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 Falls. Reviews last updated September 14, 2026.
Peruse reviews from past customers who have flown with Delta and United Airlines from St. Louis to Idaho Falls to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.5
Boarding
8.1
Entertainment
7.8
Food
7.2
Comfort
7.8
Overall
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Crew
8.5
Boarding
8.1
Entertainment
7.8
Food
7.2
Comfort
7.8
Overall
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Crew
8.5
Boarding
8.1
Entertainment
7.8
Food
7.2
Comfort
7.8
Overall
7.8
Reviews
1 / 20
4.0
OkayJennifer,Sep 2026
ORD - LGA
Related info for your journey
Find useful and relevant information for your journey from St. Louis to Idaho Falls. 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 Idaho Falls?
Book flights to Idaho Falls if you plan to visit one of these locationsRexburg
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
Idaho Falls flight routes
Other flight options
Other flights from St. Louis
Popular flights
Alternative routes for St. Louis to Idaho Falls
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Idaho Falls by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from St. Louis to Idaho Falls by cabin class
Find flights from St. Louis to Idaho Falls, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Other flights to Idaho Falls
Explore flights to Idaho Falls departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 14, 2026.
St. Louis and Idaho Falls flights
Browse other St. Louis and Idaho Falls flight options. Last updated on September 14, 2026.
Other flights from St. Louis
Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on September 14, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top 2 airlines flying from St. Louis to Idaho Falls
Discover the top 2 airlines that operate flights from St. Louis to Idaho Falls. 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 7,457,451 searches. Data last updated September 14, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$338 | Average$532 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$446 | Average$509 | FlexibilityNo cancel fee | On-timeN/A |