$164 Cheap Flights from St. Louis (STL) to Helena (HLN)

View $164 flight on Sat, Jun 7, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Helena, MT (HLN-Helena Regional)

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Find available prices by choosing your travel dates.

Cheap Flights from St. Louis to Helena (STL-HLN)

Prices were available within the past 7 days and start at $164 for one-way flights and $327 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, May 13 - Sat, May 17
STL
St. Louis
HLN
Helena
$327 Roundtrip, found 2 days ago
$327
Roundtrip
found 2 days ago
Select Delta flight, departing Tue, May 13 from St. Louis to Helena, returning Sat, May 17, priced at $327 found 2 days ago
Alaska Airlines
Tue, May 13 - Sat, May 17
STL
St. Louis
HLN
Helena
$386 Roundtrip, found 2 days ago
$386
Roundtrip
found 2 days ago
Select Alaska Airlines flight, departing Tue, May 13 from St. Louis to Helena, returning Sat, May 17, priced at $386 found 2 days ago
United
Thu, May 29 - Sun, Jun 1
STL
St. Louis
HLN
Helena
$406 Roundtrip, found 18 hours ago
$406
Roundtrip
found 18 hours ago
Select United flight, departing Thu, May 29 from St. Louis to Helena, returning Sun, Jun 1, priced at $406 found 18 hours ago
Delta
Sat, Jun 14 - Wed, Jun 18
STL
St. Louis
HLN
Helena
$407 Roundtrip, found 1 day ago
$407
Roundtrip
found 1 day ago
Select Delta flight, departing Sat, Jun 14 from St. Louis to Helena, returning Wed, Jun 18, priced at $407 found 1 day ago
United
Thu, May 29 - Sun, Jun 1
STL
St. Louis
HLN
Helena
$412 Roundtrip, found 18 hours ago
$412
Roundtrip
found 18 hours ago
Select United flight, departing Thu, May 29 from St. Louis to Helena, returning Sun, Jun 1, priced at $412 found 18 hours ago
Delta
Wed, Jun 11 - Wed, Jun 18
STL
St. Louis
HLN
Helena
$412 Roundtrip, found 3 days ago
$412
Roundtrip
found 3 days ago
Select Delta flight, departing Wed, Jun 11 from St. Louis to Helena, returning Wed, Jun 18, priced at $412 found 3 days ago
Hawaiian Airlines
Tue, May 13 - Tue, May 27
STL
St. Louis
HLN
Helena
$412 Roundtrip, found 2 days ago
$412
Roundtrip
found 2 days ago
Select Hawaiian Airlines flight, departing Tue, May 13 from St. Louis to Helena, returning Tue, May 27, priced at $412 found 2 days ago
Delta
Sat, Jun 7 - Wed, Jun 18
STL
St. Louis
HLN
Helena
$417 Roundtrip, found 3 days ago
$417
Roundtrip
found 3 days ago
Select Delta flight, departing Sat, Jun 7 from St. Louis to Helena, returning Wed, Jun 18, priced at $417 found 3 days ago
United
Tue, Jun 10 - Wed, Jun 18
STL
St. Louis
HLN
Helena
$419 Roundtrip, found 3 days ago
$419
Roundtrip
found 3 days ago
Select United flight, departing Tue, Jun 10 from St. Louis to Helena, returning Wed, Jun 18, priced at $419 found 3 days ago
United
Thu, May 29 - Sun, Jun 1
STL
St. Louis
HLN
Helena
$427 Roundtrip, found 18 hours ago
$427
Roundtrip
found 18 hours ago
Select United flight, departing Thu, May 29 from St. Louis to Helena, returning Sun, Jun 1, priced at $427 found 18 hours ago
Flights from St. Louis (STL) to Helena (HLN)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Helena Regional
Airlines serving
Alaska Airlines, Delta, United
Roundtrip price
$326
Distance
1220 mi

St. Louis to Helena Flights

The cheapest times to fly from St. Louis to Helena

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Helena are during the month of May. You can find some of the cheapest flights from St. Louis to Helena with Expedia's search tool and vast selection of airlines.

The best time to book a flight from St. Louis to Helena

Sunday is one of the best days to book for cheap flights from St. Louis to Helena: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

How to find cheap round-trip tickets from St. Louis to Helena

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Helena in 2025. You can also book with separate airlines for your outbound and return journeys, from $164 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Helena flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Helena airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

*Terms apply.

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Helena Regional Airport (HLN) cost?
Discover the latest flight deals from STL to HLN by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from STL to HLN?
The cheapest flights from STL to HLN are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from STL to HLN?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from STL to HLN. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Helena Regional Airport (HLN)?
Direct flights from Lambert-St. Louis Intl. Airport (STL) to Helena Regional Airport (HLN) aren’t available daily, so you’ll have to take a flight with a layover. Explore your options with our filter tool. Enter your dates and click on either “1 Stop” or “2+ Stops.”
What day of the week has the most flights from STL to HLN?
Friday is typically the busiest day for flights, while Tuesday tends to be the quietest.* Keep in mind that flight schedules can vary depending on various factors, including the time of year and carrier.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Helena Regional Airport (HLN)?
To reach Helena Regional Airport (HLN) on schedule, select a flight that leaves from Lambert-St. Louis Intl. Airport (STL) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Helena Regional Airport (HLN) last-minute?
Waiting until right before your break to book a flight from STL to HLN generally means paying more. While it’s possible to find some last-minute deals, they aren’t always guaranteed. Keep your travel schedule open to boost your chances of scoring a bargain.
Is it cheaper to book a STL to HLN flight and hotel package?
Compared with arranging flights and hotels separately, booking a STL to HLN flight and hotel package with Expedia could lead to significant savings. Better still, having everything in one convenient place will take the hassle out of travel planning. Just secure your flights and select from our extensive range of stays, then customize your trip with extras like tours, activities and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Helena Regional Airport (HLN)?
In most cases, you’re able to reschedule or cancel your STL to HLN flight. However, there may be additional fees, especially if you made your booking over 24 hours ago. Check your itinerary for the airline’s fees and policies on flight changes, or if you want more information, head to our Customer Service portal.

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*Available to One Key members.