IDA - STL

$217 Find Cheap Flights from Idaho Falls to St. Louis - Compare and Save

1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$392
Typical prices: $443-$645
Alaska Airlines
Wed 10/31Sun 11/4
IDA - STL • 1 stop
Cheapest one-way
$217
Typical prices: $242-$405
United Airlines
Thu 12/20
IDA - STL • 1 stop
Nonstop flights
Not available
There are currently no direct flights between Idaho Falls and St. Louis. You'll need to take a connecting flight to reach the destination.
Insights
Insights
When to travel
May
Cheapest • 15% price drop
October
Most popular
Good to know
+1
Good to know
+1
Top layover airports
Seattle/Tacoma Intl (SEA)
Cheapest • Avg $397 (round-trip)
Denver Intl (DEN)
Shortest trip • 5h 32m (one-way)
Insights
Insights
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Booking Insights
Flight Deals

Cheap Flights from Idaho Falls to St. Louis (IDA-STL)

 
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Idaho Falls to St. Louis

Sat, Oct 31 - Wed, Nov 4
Alaska Airlines Logo
6:09 am - 3:44 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
8h 35m1 stop Seattle/Tacoma Intl
Alaska Airlines Logo
6:00 am - 3:18 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
10h 18m1 stop Seattle/Tacoma Intl
$392Alaska Airlines
Fri, Oct 2 - Tue, Oct 6
United Airlines Logo
5:51 pm - 11:44 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
4h 53m1 stop Denver Intl
United Airlines Logo
4:39 pm - 8:54 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
5h 15m1 stop Denver Intl
$399United Airlines
Tue, Sep 29 - Sat, Oct 3
United Airlines Logo
5:51 pm - 11:44 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
4h 53m1 stop Denver Intl
United Airlines Logo
9:00 am - 1:24 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
5h 24m1 stop Denver Intl
$399United Airlines
Tue, Sep 29 - Sat, Oct 3
United Airlines Logo
5:51 pm - 11:44 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
4h 53m1 stop Denver Intl
United Airlines Logo
8:00 am - 3:24 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
8h 24m2 stops Chicago O'Hare Intl Denver Intl
$404United Airlines
Sat, Oct 31 - Wed, Nov 4
Alaska Airlines Logo
6:09 am - 3:44 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
8h 35m1 stop Seattle/Tacoma Intl
Alaska Airlines Logo
6:00 am - 3:18 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
10h 18m1 stop Seattle/Tacoma Intl
$419Alaska Airlines
Sun, Sep 27 - Fri, Oct 2
Alaska Airlines Logo
6:18 am - 2:21 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
7h 03m1 stop Seattle/Tacoma Intl
Alaska Airlines Logo
3:19 pm - 10:56 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
8h 37m1 stop Seattle/Tacoma Intl
$527Alaska Airlines
Thu, Oct 8 - Sun, Oct 11
American Airlines Logo
1:39 pm - 9:59 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
7h 20m1 stop Dallas/Fort Worth
American Airlines Logo
5:40 am - 1:09 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
8h 29m1 stop Dallas/Fort Worth
$711American Airlines
Sun, Sep 27 - Thu, Oct 1
American Airlines Logo
2:08 pm - 11:43 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
8h 35m1 stop Dallas/Fort Worth
American Airlines Logo
5:43 am - 11:45 amSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
7h 02m1 stop Dallas/Fort Worth
$720American Airlines
Tue, Dec 22 - Tue, Dec 29
American Airlines Logo
6:00 am - 2:20 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
7h 20m1 stop Dallas/Fort Worth
American Airlines Logo
2:50 pm - 9:46 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
7h 56m1 stop Dallas/Fort Worth
$766American Airlines
Sun, Sep 27 - Fri, Oct 2
Alaska Airlines Logo
6:18 am - 2:21 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
7h 03m1 stop Seattle/Tacoma Intl
Alaska Airlines Logo
6:08 pm - 10:59 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
29h 51m2 stops Portland Seattle/Tacoma Intl
$852Alaska Airlines
Booking Insights

Price, demand and travel trends for Idaho Falls to St. Louis flights

Use KAYAK data on prices, travel dates, airlines and seasonal trends to compare options and book flights from Idaho Falls to St. Louis with more confidence.

How much is a round-trip flight from Idaho Falls to St. Louis?

Round-trip flights from Idaho Falls to St. Louis start at $392. Prices are below average for this route right now, with typical round-trip fares ranging from $443 to $645. The lowest price found in the past 5 days was $392 on Alaska Airlines.

What's the cheapest day of the week to fly from Idaho Falls to St. Louis?

Friday is the cheapest day of the week to fly from Idaho Falls to St. Louis, it is 8% cheaper than the average day. Monday is the most expensive day with flight prices 24% higher than average. Based on deals found by KAYAK users in the last 12 months.

What is the cheapest month to fly from Idaho Falls to St. Louis?

•May is the cheapest month to fly from Idaho Falls to St. Louis at $443 round-trip.
•December ($863) and February ($837) are the most expensive months.
•The price difference between flying in the cheapest and most expensive months is 94% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

Find deals

Key details for Idaho Falls to St. Louis flights

Low season

January

Cheapest flight

$217
Best time to beat the crowds but there is an average 25% increase in price.
Most popular time to fly and prices are also 6% lower on average.
Flight from Idaho Falls to St. Louis

When to book flights from Idaho Falls to St. Louis

Are your dates flexible? Find out the best times to travel from Idaho Falls to St. Louis based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

Your Idaho Falls to St. Louis flight questions, answered

Find helpful route details based on KAYAK data, including flight times, airports, airlines and booking questions.

  • Which airports can I use when flying from Idaho Falls to St. Louis?

    Flights from Idaho Falls to St. Louis usually depart from Idaho Falls Fanning Field (IDA) and arrive at Lambert-St Louis (STL).

  • What cabin classes can I book on flights from Idaho Falls to St. Louis?

    Only Economy Class is available on flights from Idaho Falls to St. Louis.

  • Which airports do connecting flights from Idaho Falls to St. Louis pass through?

    One-stop flights from Idaho Falls to St. Louis most commonly connect through:

    • Denver Intl (DEN) - 75% of one-stop connections
    • Salt Lake City (SLC) - 15% of one-stop connections
    • Dallas/Fort Worth (DFW) - 4% of one-stop connections
    • Chicago O'Hare Intl (ORD) - 3% of one-stop connections

    Denver Intl (DEN) handles the largest share of one-stop connections on this route.

  • Can I save money by using flexible dates for flights from Idaho Falls to St. Louis?

    Yes. Being flexible with your travel dates can save you up to 26% on the Idaho Falls to St. Louis route. Friday is the cheapest departure day at $480 round-trip on average, while Monday is the most expensive at $647, a difference of $167. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

  • What popular places can I visit in St. Louis?

    Some of the most popular sights in St. Louis are Busch Stadium, Enterprise Center and America's Center Convention Complex. These are among the most viewed places in St. Louis on KAYAK.

  • How long is a flight from Idaho Falls to St. Louis?

    A nonstop flight from Idaho Falls to St. Louis takes 0h 00m, covering 1,171 miles.

  • Do I need a passport to fly from Idaho Falls to St. Louis?

    No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.

  • Have flight prices from Idaho Falls to St. Louis changed much recently?

    Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about $392 to $1,466. That means the highest observed fare was about 4x higher than the lowest one.

  • How are flight prices from Idaho Falls to St. Louis looking right now?

    One-way fares from Idaho Falls to St. Louis are currently higher than usual. Average one-way flight prices are about $444, which is 43% above the typical average for this route.

  • How much time can I save by choosing a different layover airport from Idaho Falls to St. Louis?

    Flying via Denver Intl (DEN) gives the shortest average 1-stop total travel time at 5h 32m, compared with 5h 55m via Salt Lake City (SLC) and 7h 58m via Dallas/Fort Worth (DFW).

  • What is the time difference between Idaho Falls and St. Louis?

    St. Louis is 1 hour ahead of Idaho Falls (Central Time vs Mountain Time). Plan for the time shift when scheduling connections or first-day activities.

  • What car rental options are available at Lambert-St Louis Airport (STL)?

    Lambert-St Louis Airport (STL) hosts 5 major car rental companies, with daily rates starting from around $31 for economy cars. Top options include:
    • Hertz
    • Budget
    • Alamo
    • Enterprise Rent-A-Car
    • Payless

  • How much should I expect to pay for a Idaho Falls to St. Louis flight?

    Round-trip flights from Idaho Falls to St. Louis range from $443 to $645, with an average of $520 over the past 12 months. Anything below $443 counts as a good deal.

Your guide to booking Idaho Falls to St. Louis flights

Get tips on when to book, when to fly and what to know before your trip.
  • If your dates can be flexible, aim for a Friday departure instead of Monday. On this route, Friday flights average $480 - about $167 less than Monday (26% savings) based on the last 12 months.
  • If you can choose when to travel, plan your Idaho Falls to St. Louis trip for May. Fares historically average $443 round-trip in that month - typically $420 less than the most expensive month, which is December (based on the last 12 months).
  • If you're arriving late at night and need somewhere to stay, check out these hotels close to Lambert-St Louis Airport.
    - Drury Inn & Suites St. Louis Airport
    - Renaissance St. Louis Airport Hotel
    - DoubleTree by Hilton St. Louis Airport

More options for your flight from Idaho Falls to St. Louis

Complete your trip to St. Louis with a hotel stay or car rental

Car rentals in St. Louis
Hotels in St. Louis
Vacations in St. Louis