IDA - STL

$349 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
$349
Typical prices: $443-$738
Delta
Sat 4/7Sun 4/15
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 • 24% price drop
April
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 37m (one-way)
Insights
Insights
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We hope you love your trip to St. Louis!
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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

Wed, Apr 7 - Thu, Apr 15
Delta Logo
6:45 pm - 12:36 amIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
4h 51m1 stop Salt Lake City
Delta Logo
2:15 pm - 6:14 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
4h 59m1 stop Salt Lake City
$349Delta
Wed, Apr 7 - Thu, Apr 15
Delta Logo
6:45 pm - 12:36 amIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
4h 51m1 stop Salt Lake City
Delta Logo
9:45 am - 6:14 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
9h 29m2 stops Minneapolis St Paul Salt Lake City
$354Delta
Fri, Nov 13 - Tue, Nov 17
Alaska Airlines Logo
6:04 am - 2:25 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
7h 21m1 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
$399Alaska Airlines
Fri, Nov 13 - Tue, Nov 17
Delta Logo
6:57 pm - 12:40 amIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
4h 43m1 stop Salt Lake City
Delta Logo
2:21 pm - 9:59 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
8h 38m2 stops Detroit Metropolitan Wayne County Salt Lake City
$404Delta
Sat, Dec 5 - Wed, Dec 9
United Airlines Logo
2:40 pm - 8:57 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
5h 17m1 stop Denver Intl
United Airlines Logo
8:40 am - 1:37 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
5h 57m1 stop Denver Intl
$459United Airlines
Sat, Dec 5 - Wed, Dec 9
United Airlines Logo
2:40 pm - 8:57 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
5h 17m1 stop Denver Intl
United Airlines Logo
6:30 am - 3:29 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
9h 59m2 stops Chicago O'Hare Intl Denver Intl
$464United Airlines
Fri, Nov 13 - Tue, Nov 17
American Airlines Logo
6:36 am - 7:22 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
11h 46m2 stops Phoenix Sky Harbor Intl Chicago O'Hare Intl
American Airlines Logo
11:35 am - 10:59 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
12h 24m2 stops Chicago O'Hare Intl Phoenix Sky Harbor Intl
$464American Airlines
Sat, Nov 14 - Wed, Nov 18
Alaska Airlines Logo
6:04 am - 3:21 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
8h 17m1 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
$514Alaska Airlines
Sat, Nov 14 - Wed, Nov 18
Alaska Airlines Logo
6:04 am - 3:21 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
8h 17m1 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
$525Alaska Airlines
Thu, Apr 15 - Sun, Apr 18
American Airlines Logo
1:43 pm - 11:04 pmIDA  Idaho Falls Fanning Field-STL Lambert-St Louis
8h 21m1 stop Dallas/Fort Worth
American Airlines Logo
5:20 am - 1:13 pmSTL  Lambert-St Louis-IDA Idaho Falls Fanning Field
8h 53m1 stop Dallas/Fort Worth
$578American 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 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 typically range from $443 to $738. The lowest price found in the past 5 days was $349, on Delta.

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

Based on deals KAYAK users found in the last 12 months, Friday is the cheapest day of the week to fly from Idaho Falls to St. Louis. It’s 28% cheaper than the average day, while Tuesday is the most expensive, with prices 51% higher.

What’s 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.
•September ($943) and December ($863) are the most expensive months.
•The price difference between flying in the cheapest and most expensive months is 112% 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

February

Cheapest flight

$349
Beat the crowds with an average 31% drop in travelers.
The most popular month to fly with an average 24% increase in travelers.
Round-trip 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 answers about this route, including flight times, airports, airlines and booking tips.

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

    Two cabin classes are available on flights from Idaho Falls to St. Louis:

    • Economy Class
    • First Class

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

    A nonstop flight from Idaho Falls to St. Louis takes 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.

  • 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 $738, with an average of $584 over the past 12 months. Anything below $443 counts as a good deal.

  • 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 $349 to $1,028. That means the highest observed fare was about 3x higher than the lowest one.

  • 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 averaging $78 for economy cars. Top options include:

    • Hertz
    • Budget
    • Alamo
    • Enterprise Rent-A-Car
    • Payless

  • 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).

  • 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) - 66% of one-stop connections
    • Salt Lake City (SLC) - 16% of one-stop connections
    • Dallas/Fort Worth (DFW) - 12% of one-stop connections
    • Chicago O'Hare Intl (ORD) - 3% of one-stop connections

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

    Yes. Flexible dates can save you up to 53% on flights from Idaho Falls to St. Louis. Friday is the cheapest departure day at $421 round-trip on average, while Tuesday is the most expensive at $882, a difference of $461.

    KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

  • 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 37m, compared with 5h 54m via Salt Lake City (SLC) and 7h 59m via Chicago O'Hare Intl (ORD).

  • 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 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.

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 are flexible, aim for a Friday departure and avoid flying on Tuesday. On this route, Friday flights average $421, about $461 less than Tuesday fares (52% 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 $500 less than the most expensive month, which is September (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.

    • Renaissance St. Louis Airport Hotel
    • Drury Inn & Suites St. Louis Airport
    • 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