$419 Cheap Flights from St. Louis (STL) to Helsinki (HEL)

View $419 flight on Tue, Mar 3, 2026Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Helsinki-Vantaa Airport (HEL)

Cheap Flights from St. Louis to Helsinki (STL-HEL)

Prices were available within the past 7 days and start at $419 for one-way flights and $482 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Mon, Sep 22 - Wed, Oct 1
STL
St. Louis
HEL
Helsinki
$482 Roundtrip, found 11 hours ago
$482
Roundtrip
found 11 hours ago
Select American Airlines flight, departing Mon, Sep 22 from St. Louis to Helsinki, returning Wed, Oct 1, priced at $482 found 11 hours ago
British Airways
Mon, Sep 22 - Wed, Oct 1
STL
St. Louis
HEL
Helsinki
$482 Roundtrip, found 11 hours ago
$482
Roundtrip
found 11 hours ago
Select British Airways flight, departing Mon, Sep 22 from St. Louis to Helsinki, returning Wed, Oct 1, priced at $482 found 11 hours ago
American Airlines
Mon, Sep 22 - Wed, Oct 1
STL
St. Louis
HEL
Helsinki
$486 Roundtrip, found 11 hours ago
$486
Roundtrip
found 11 hours ago
Select American Airlines flight, departing Mon, Sep 22 from St. Louis to Helsinki, returning Wed, Oct 1, priced at $486 found 11 hours ago
American Airlines
Mon, Sep 22 - Wed, Oct 1
STL
St. Louis
HEL
Helsinki
$491 Roundtrip, found 11 hours ago
$491
Roundtrip
found 11 hours ago
Select American Airlines flight, departing Mon, Sep 22 from St. Louis to Helsinki, returning Wed, Oct 1, priced at $491 found 11 hours ago
American Airlines
Mon, Sep 22 - Wed, Oct 1
STL
St. Louis
HEL
Helsinki
$496 Roundtrip, found 11 hours ago
$496
Roundtrip
found 11 hours ago
Select American Airlines flight, departing Mon, Sep 22 from St. Louis to Helsinki, returning Wed, Oct 1, priced at $496 found 11 hours ago
British Airways
Wed, Oct 8 - Fri, Oct 17
STL
St. Louis
HEL
Helsinki
$501 Roundtrip, just found
$501
Roundtrip
just found
Select British Airways flight, departing Wed, Oct 8 from St. Louis to Helsinki, returning Fri, Oct 17, priced at $501 just found
United
Wed, Nov 19 - Wed, Nov 26
STL
St. Louis
HEL
Helsinki
$506 Roundtrip, found 14 hours ago
$506
Roundtrip
found 14 hours ago
Select United flight, departing Wed, Nov 19 from St. Louis to Helsinki, returning Wed, Nov 26, priced at $506 found 14 hours ago
United
Tue, Nov 18 - Wed, Nov 26
STL
St. Louis
HEL
Helsinki
$506 Roundtrip, found 14 hours ago
$506
Roundtrip
found 14 hours ago
Select United flight, departing Tue, Nov 18 from St. Louis to Helsinki, returning Wed, Nov 26, priced at $506 found 14 hours ago
Lufthansa
Wed, May 6 - Wed, May 13
STL
St. Louis
HEL
Helsinki
$508 Roundtrip, found 2 days ago
$508
Roundtrip
found 2 days ago
Select Lufthansa flight, departing Wed, May 6 from St. Louis to Helsinki, returning Wed, May 13, priced at $508 found 2 days ago
Air Canada
Tue, Mar 10 - Wed, Mar 18
STL
St. Louis
HEL
Helsinki
$510 Roundtrip, found 15 hours ago
$510
Roundtrip
found 15 hours ago
Select Air Canada flight, departing Tue, Mar 10 from St. Louis to Helsinki, returning Wed, Mar 18, priced at $510 found 15 hours ago

Find the cheapest month to fly from St. Louis (STL) to Helsinki (HEL)

November is typically the cheapest month to fly

From $478 - $1,270 per traveler.

Graph displaying average flight prices per month

Flights from St. Louis (STL) to Helsinki (HEL)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Vantaa
Airlines serving
Air Canada, Air France, American Airlines, British Airways, Delta, Finnair, Iberia, KLM, Lufthansa, Scandinavian Airlines, Turkish Airlines, United
Roundtrip price
$481
Distance
4681 mi

St. Louis to Helsinki Flights

The cheapest times to fly from St. Louis to Helsinki

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 Helsinki are during the month of September. You can find some of the cheapest flights from St. Louis to Helsinki with Expedia's search tool and vast selection of airlines.

 

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

Sunday is one of the best days to book for cheap flights from St. Louis to Helsinki: 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 Helsinki

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 Helsinki in 2025. You can also book with separate airlines for your outbound and return journeys, from $419 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 Helsinki 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 Helsinki 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 Vantaa Airport (HEL) cost?
Lock in a cheap one-way flight from $419 or cheap return flight from $482 from Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL)?
September is the cheapest month to fly from STL to HEL. Avoiding peak travel times is often the key to finding a great deal.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL)?
To find the cheapest airline flying from STL to HEL, use Expedia's filter tool. Customize your search based on your travel needs, such as preferred carriers and ideal departure window. You can then sort your results by "Price (lowest to highest)" to list the most affordable options first.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL)?
You'll need to hop on a flight with a layover when traveling from Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL). Direct flights don't operate daily on this route. However, simply filter your search to include one or two stops to find an option that works for you.
What day of the week has the most flights from STL to HEL?
Friday is usually the busiest day for flights, while Tuesday is often the quietest.* Just remember that flight schedules can change depending on a number of 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 Vantaa Airport (HEL)?
To avoid potential delays on the Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL) route, travel before 3 PM. Departures after this hour have a 22% higher chance of being canceled.**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 Vantaa Airport (HEL) last-minute?
Last-minute bookings from STL to HEL are typically more expensive. To secure the best prices, start searching for flights well in advance. That said, if your travel plans are flexible, you may land a cheap ticket right before your journey.
Is it cheaper to book a STL to HEL flight and hotel package?
Securing a STL to HEL flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Pick from our impressive range of accommodations and then add car rentals, flights and activities to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Vantaa Airport (HEL)?
If you reserved your STL to HEL flight within the last 24 hours, you may be able to cancel or modify it without any fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

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*Available to One Key members.