$436 Cheap Flights from Basel (BSL) to Seattle (SEA)

View $436 flight on Tue, Dec 8, 2026Opens in a new window

Popular airlines from EuroAirport Airport (BSL) to Seattle-Tacoma International Airport (SEA)

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Cheap Flights from Basel to Seattle (BSL-SEA)

Prices were available within the past 7 days and start at $436 for one-way flights and $783 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Thu, Jun 4 - Sun, Jun 21
BSL
Basel
SEA
Seattle
$783 Roundtrip, just found
$783
Roundtrip
just found
Select American Airlines flight, departing Thu, Jun 4 from Basel to Seattle, returning Sun, Jun 21, priced at $783 just found
Lufthansa
Wed, Aug 19 - Wed, Sep 9
BSL
Basel
SEA
Seattle
$797 Roundtrip, found 1 day ago
$797
Roundtrip
found 1 day ago
Select Lufthansa flight, departing Wed, Aug 19 from Basel to Seattle, returning Wed, Sep 9, priced at $797 found 1 day ago
British Airways
Thu, Jun 4 - Sun, Jun 21
BSL
Basel
SEA
Seattle
$802 Roundtrip, just found
$802
Roundtrip
just found
Select British Airways flight, departing Thu, Jun 4 from Basel to Seattle, returning Sun, Jun 21, priced at $802 just found
Lufthansa
Wed, Aug 19 - Wed, Sep 9
BSL
Basel
SEA
Seattle
$804 Roundtrip, found 1 day ago
$804
Roundtrip
found 1 day ago
Select Lufthansa flight, departing Wed, Aug 19 from Basel to Seattle, returning Wed, Sep 9, priced at $804 found 1 day ago
Lufthansa
Wed, Aug 19 - Wed, Sep 9
BSL
Basel
SEA
Seattle
$804 Roundtrip, found 1 day ago
$804
Roundtrip
found 1 day ago
Select Lufthansa flight, departing Wed, Aug 19 from Basel to Seattle, returning Wed, Sep 9, priced at $804 found 1 day ago
Lufthansa
Wed, Aug 19 - Wed, Sep 9
BSL
Basel
SEA
Seattle
$811 Roundtrip, found 1 day ago
$811
Roundtrip
found 1 day ago
Select Lufthansa flight, departing Wed, Aug 19 from Basel to Seattle, returning Wed, Sep 9, priced at $811 found 1 day ago
Lufthansa
Mon, Jul 6 - Tue, Jul 28
BSL
Basel
SEA
Seattle
$815 Roundtrip, found 15 hours ago
$815
Roundtrip
found 15 hours ago
Select Lufthansa flight, departing Mon, Jul 6 from Basel to Seattle, returning Tue, Jul 28, priced at $815 found 15 hours ago
Lufthansa
Thu, Jun 4 - Sun, Jun 21
BSL
Basel
SEA
Seattle
$815 Roundtrip, just found
$815
Roundtrip
just found
Select Lufthansa flight, departing Thu, Jun 4 from Basel to Seattle, returning Sun, Jun 21, priced at $815 just found
United
Thu, Jun 4 - Sun, Jun 21
BSL
Basel
SEA
Seattle
$833 Roundtrip, just found
$833
Roundtrip
just found
Select United flight, departing Thu, Jun 4 from Basel to Seattle, returning Sun, Jun 21, priced at $833 just found
Air Canada
Wed, Aug 19 - Wed, Sep 9
BSL
Basel
SEA
Seattle
$875 Roundtrip, found 1 day ago
$875
Roundtrip
found 1 day ago
Select Air Canada flight, departing Wed, Aug 19 from Basel to Seattle, returning Wed, Sep 9, priced at $875 found 1 day ago

Frequently asked questions

How much does a flight from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) cost?
You can find cheap one-way flights and cheap return flights from $783 Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) with Expedia. One-way flights typically cost between $738 and $6709, and return flights often range between $704 and $5599. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The cheapest month to fly from BSL to SEA is June when demand is low. Traveling in off-peak or shoulder months is usually a good way to secure cheap tickets, just remember to avoid flying during holidays if you're able to. Use the calendar view in your search to see which months have low fares on this route.
Which airlines fly direct from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
Enter BSL to SEA and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
American Airlines is one of the cheapest airlines offering connecting flights from Basel (BSL) to Seattle, WA (SEA), with round-trip tickets starting from around $588. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
To find a cheap flight from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best time to fly from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.
What is the earliest flight from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The earliest flight from EuroAirport Basel (BSL) to Seattle - Tacoma International (SEA) usually departs at around 5:15 AM, operated by Lufthansa and Air Canada. This seasonal service is active in June, giving you a great opportunity to maximize your time in Seattle. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
The most popular departure times for flights from Basel (BSL) to Seattle, WA (SEA) are in the late morning, from 9am to 12pm. About 43% of passengers prefer this time window. Many major carriers, including British Airways, American Airlines and Swiss International Air Lines, offer flights during this window. This timing is popular because it allows for a comfortable start to your travel day.
How long does it take to fly from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
A flight from BSL to SEA with a layover takes around 14 hours 50 minutes, with the route covering approximately 5,211 miles. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
Business class is available on flights from BSL to SEA. Airlines that offer business class service on this route include:

  • British Airways
  • Lufthansa
  • Swiss International Air Lines
  • Air Dolomiti
  • Austrian Airlines
  • KLM
  • Turkish Airlines
  • Hop!

How do I earn miles on a Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight with Expedia?
It's easy to earn miles on a Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Seattle from EuroAirport Basel (BSL)?
From EuroAirport Basel (BSL), you can fly into Seattle - Tacoma Intl. (SEA) to reach Seattle. Some flights may connect through major hubs like Frankfurt Intl. (FRA), Heathrow (LHR), QFB (QFB) before reaching Seattle. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) at the last minute?
Typically, booking a last minute flight from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight and hotel package?
Securing a Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) Seattle Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.)?
If you booked your Basel (BSL-EuroAirport) to Seattle, WA (SEA-Seattle - Tacoma Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, 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.

Travel information

Origin airport
EuroAirport
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Air Canada, Austrian Airlines, British Airways, Iberia, Lufthansa, Swiss International Air Lines, Turkish Airlines
Roundtrip price
$783
Distance
5210 mi

Book with confidence

Basel to Seattle Flights

The cheapest times to fly from Basel to Seattle

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 Basel to Seattle are during the month of June. You can find some of the cheapest flights from Basel to Seattle with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Basel to Seattle

Sunday is one of the best days to book for cheap flights from Basel to Seattle: 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 Basel to Seattle

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 Basel to Seattle in 2026. You can also book with separate airlines for your outbound and return journeys, from $436 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 Basel to Seattle 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 Basel to Seattle 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.

 

Basel to Seattle Flights

*Flight schedules are subject to change.

*Available to One Key members.

 

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