$624 Cheap Finnair flights St. Louis (STL) to Tromsø (TOS)

View $624 flight on Mon, Aug 25, 2025Opens in a new window

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$624 Cheap Finnair flights St. Louis (STL) to Tromsø (TOS)

Prices were available within the past 7 days and start at $624 for one-way flights and $989 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Finnair
Mon, Aug 25 - Wed, Sep 3
STL
St. Louis
TOS
Tromsø
$989 Roundtrip, found 1 day ago
$989
Roundtrip
found 1 day ago
Select Finnair flight, departing Mon, Aug 25 from St. Louis to Tromsø, returning Wed, Sep 3, priced at $989 found 1 day ago
Flights from St. Louis (STL) to Tromsø (TOS)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Langnes
Airlines serving
Finnair, Lufthansa
Popular airline
Finnair
Distance
4156 mi

Frequently asked questions

How much is a Finnair flight from Lambert-St. Louis Intl. Airport (STL) to Langnes Airport (TOS)?
Finding cheap one-way Finnair flights from STL to TOS from $624 on Expedia is simple --- just filter by "Price (lowest to highest)." Or check out our affordable return fares from $989 for your next adventure.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.
What is the cheapest month to fly from STL to TOS with Finnair?
Browse for round-trip or one-way flights to Tromsø in May or April. You could find an affordable fare with Finnair during these off-peak months.
What is the cheapest time to book flights from Lambert-St. Louis Intl. Airport (STL) to Langnes Airport (TOS) with Finnair?
To find cheap flights from STL to TOS with Finnair, start your search about one month before your planned departure. You can save 17% when you lock in your international tickets 18 to 29 days ahead instead of booking four to five months in advance. Another good tip? Booking on Sunday can lead to average savings of 17% compared to Friday (the most expensive day).**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.
Does Finnair fly nonstop from Lambert-St. Louis Intl. Airport (STL) to Langnes Airport (TOS)?
Use our "Nonstop" filter when looking for direct Finnair flights from STL to TOS. It's also a good way to compare other airlines offering the same nonstop trip.
What is the earliest Finnair flight from STL to TOS?
Sort your results by "Early Morning" and "Morning" to find the earliest flights from STL to TOS. Taking off early means you're 20% less likely to experience cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports does Finnair fly into in Tromsø?
Finnair flights from Lambert-St. Louis Intl. Airport (STL) to Tromsø arrive at Langnes Airport (TOS). This is the main gateway to this city.
What kind of luggage can I take on a Finnair flight from Lambert-St. Louis Intl. Airport (STL) to Langnes Airport (TOS)?
Finnair allows travelers to bring 1 checked-in bag weighing up to 50 lb with dimensions not exceeding 62 inches on standard economy flights from STL to TOS. You can also bring 1 cabin bag with you in the cabin. This hand luggage must not exceed 9 inches x 15 inches x 15 inches and weigh no more than 22 lb. Baggage rules can differ depending on your cabin class and fare type, so double-check your booking or Finnair's website to avoid any extra fees at the airport.
Why fly with Finnair from STL to TOS?
Traveling from STL to TOS with Finnair comes with a host of benefits, such as a rewarding loyalty program and a 4-star airline rating. Plus, when booking through Expedia, One Key™ members can earn OneKeyCash™* to redeem on select future travel purchases. That's in addition to the Finnair Plus points you can earn with Finnair.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.
Can I change or cancel my Finnair flight from Lambert-St. Louis Intl. Airport (STL) to Langnes Airport (TOS)?
Depending on the type of ticket you purchased, a fee is typically charged if you cancel or change your booking more than 24 hours after it's been confirmed. To find flexible plane tickets, select our "Changes included" and "No cancel fee" boxes when you search for flights. To learn more about modifying or canceling your reservation, head to "Trips," select your flight and tick "Manage Booking."

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*Available to One Key members.