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$388+ Cheap flights from Seattle (SEA) to Basel EuroAirport Swiss (BSL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/16. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BSL
Nov 27 — Dec 41
Thu 11/27
Thu 12/4
1 adult, Economy
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Find flight deals from Seattle to Basel

Cheapest flights from Seattle to Basel
Explore the most affordable flight options available from Seattle to Basel. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 28, 2025.

This Kiwi.com deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/63:40 pmSEA - BSL
2 stops37h 05mLufthansa
Sat 12/138:15 pmBSL - SEA
1 stop26h 05mLufthansa
Deal found 10/27$471
This United Airlines deal was found by Cheapflights users on 10/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/105:11 pmSEA - BSL
2 stops17h 29mUnited Airlines
Wed 12/179:50 amBSL - SEA
1 stop12h 30mUnited Airlines
Deal found 10/26$486
This Air France deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/262:05 pmSEA - BSL
1 stop14h 45mAir France
Sun 12/75:55 pmBSL - SEA
1 stop26h 55mAir France
Deal found 10/28$496
This KLM deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/262:05 pmSEA - BSL
1 stop14h 45mKLM
Sun 12/76:05 amBSL - SEA
2 stops19h 49mKLM
Deal found 10/28$507
This United deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/263:48 pmSEA - BSL
2 stops18h 52mMultiple Airlines
Sun 12/76:45 amBSL - SEA
2 stops21h 31mMultiple Airlines
Deal found 10/28$509
This Air France deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/119:25 amSEA - BSL
2 stops16h 15mAir France
Thu 12/186:05 amBSL - SEA
1 stop14h 45mAir France
Deal found 10/27$514
This Mytrip deal was found by Cheapflights users on 10/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/63:40 pmSEA - BSL
2 stops37h 05mMultiple Airlines
Sat 12/138:15 pmBSL - SEA
1 stop26h 05mMultiple Airlines
Deal found 10/26$516
This Gotogate deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/510:05 amSEA - BSL
2 stops21h 00mMultiple Airlines
Sat 12/138:15 pmBSL - SEA
1 stop26h 05mMultiple Airlines
Deal found 10/27$527
This Air France deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/52:05 pmSEA - BSL
1 stop34h 45mAir France
Sat 12/1311:15 amBSL - SEA
1 stop33h 35mAir France
Deal found 10/27$532
This Air France deal was found by Cheapflights users on 10/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/63:05 pmSEA - BSL
1 stop22h 00mAir France
Sat 12/1311:15 amBSL - SEA
1 stop33h 35mAir France
Deal found 10/26$536

Cheap flight deals from Seattle to Basel

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Basel (BSL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated October 28, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$471
(Kiwi.com)

One-way from

$388
(Cheapflightsfares)

Popular in

May

Cheapest in

August

Average price

$540
Provider with most accurate pricing for Seattle/Tacoma Intl-Basel EuroAirport Swiss flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Basel EuroAirport Swiss flights.
Search Deals
From Seattle/Tacoma Intl to Basel EuroAirport Swiss
Search Deals
One-way flight from Seattle/Tacoma Intl to Basel EuroAirport Swiss
Search Deals
Highest demand for flights based on searches. 33% potential increase in price ($364 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 9% potential price decrease ($60 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Basel that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 28, 2025.
Use the filters below to find and compare flights from Seattle to Basel EuroAirport Swiss that are best for you.

Fly from

Seattle

Fly to

Basel

Route

Depart

Return

Price

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 12/10

5:11 pm-7:40 pm

2 stops17h 29m

Basel EuroAirport Swiss

Wed 12/17

9:50 am-1:20 pm

1 stop12h 30m

$486

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 11/26

2:05 pm-1:50 pm

1 stop14h 45m

Basel EuroAirport Swiss

Sun 12/7

5:55 pm-11:50 am

1 stop26h 55m

$496

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 11/26

2:05 pm-1:50 pm

1 stop14h 45m

Basel EuroAirport Swiss

Sun 12/7

6:05 am-4:54 pm

2 stops19h 49m

$507

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 11/26

3:48 pm-7:40 pm

2 stops18h 52m

Basel EuroAirport Swiss

Sun 12/7

6:45 am-7:16 pm

2 stops21h 31m

$509

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Thu 12/11

9:25 am-10:40 am

2 stops16h 15m

Basel EuroAirport Swiss

Thu 12/18

6:05 am-11:50 am

1 stop14h 45m

$514

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Sat 12/6

3:40 pm-1:45 pm

2 stops37h 05m

Basel EuroAirport Swiss

Sat 12/13

8:15 pm-1:20 pm

1 stop26h 05m

$516

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 12/8

1:40 pm-7:40 pm

2 stops21h 00m

Basel EuroAirport Swiss

Fri 12/26

9:50 am-1:58 pm

2 stops37h 08m

$532

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Sat 12/6

3:05 pm-10:05 pm

1 stop22h 00m

Basel EuroAirport Swiss

Sat 12/13

11:15 am-11:50 am

1 stop33h 35m

$536

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Thu 12/11

7:00 am-7:40 pm

2 stops27h 40m

Basel EuroAirport Swiss

Thu 12/18

9:50 am-12:59 am

2 stops24h 09m

$621

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Tue 11/25

3:00 pm-10:05 pm

1 stop22h 05m

Basel EuroAirport Swiss

Sun 11/30

5:55 pm-11:50 am

1 stop26h 55m

$625

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/26

Showing 1-10 of 15 results
1
2

Compare providers for flights from Seattle to Basel

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Basel in October.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-Basel EuroAirport Swiss flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Seattle-Basel EuroAirport Swiss flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Seattle-Basel EuroAirport Swiss flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Basel EuroAirport Swiss flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Basel EuroAirport Swiss flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Seattle to Basel

Have a flexible travel schedule? Discover the best time to fly to Basel from Seattle with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Basel EuroAirport Swiss

What is the cheapest month to book a flight from Seattle to Basel EuroAirport Swiss?

Currently, August is the cheapest month in which you can book a flight from Seattle to Basel EuroAirport Swiss (average of $385). Flying from Seattle to Basel EuroAirport Swiss in May is currently the most expensive (average of $817). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to BSL?

Find hourly flight availability from Seattle to Basel. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 28, 2025.

A simple way to save on the total cost of your ticket is to fly from Seattle to Basel EuroAirport Swiss in the evening. If you’re flexible enough to do this you can expect to save up to 23% on your trip compared to booking a flight in the afternoon.

Reviews of airlines servicing Basel

Get insights into the airlines that provide service to Basel. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Basel. Reviews last updated October 28, 2025.
Read reviews from past customers who have flown Lufthansa and British Airways from Seattle to Basel EuroAirport Swiss. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Lufthansa
6.8
Okay
7,535 reviews

Overall

6.8

Food

6.3

Boarding

7.0

Entertainment

6.4

Comfort

6.8

Crew

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

SFO - FRA

Convenient flight to my destination. Good entertainment options on board. I was seated close to some people who had noisy children which made sleeping a bit challenging.
Lufthansa
6.8
Okay
7,535 reviews
Lufthansa
6.8
Okay
7,535 reviews

Overall

6.8

Food

6.3

Boarding

7.0

Entertainment

6.4

Comfort

6.8

Crew

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

SFO - FRA

Convenient flight to my destination. Good entertainment options on board. I was seated close to some people who had noisy children which made sleeping a bit challenging.
British Airways
6.7
Okay
7,483 reviews
Lufthansa
6.8
Okay
7,535 reviews

Overall

6.8

Food

6.3

Boarding

7.0

Entertainment

6.4

Comfort

6.8

Crew

7.6

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

SFO - FRA

Convenient flight to my destination. Good entertainment options on board. I was seated close to some people who had noisy children which made sleeping a bit challenging.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Basel. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Seattle to Basel EuroAirport Swiss?

    Airlines like United Airlines, Air France, and KLM fly from Seattle to Basel EuroAirport Swiss in about 14h 45m. The time it takes to get you to your destination can typically vary by up to 2h 44m. The distance between Seattle and Basel EuroAirport Swiss is about 5207 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Seattle to Basel EuroAirport Swiss round-trip?

    British Airways, at $481, was found to be the cheapest airline from Seattle to Basel EuroAirport Swiss. An alternate airline flying to your destination would be Lufthansa. You may be able to fly from Seattle to Basel EuroAirport Swiss for 32% less than the average price by searching for these airlines.

  • Can I find deals for flights from Seattle to Basel that include hotel bookings?

    Yes. In addition to deals on Seattle to Basel flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Basel?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Basel.

  • Can I find deals for business class flights from Seattle to Basel?

    Yes. Cheapflights offers flight deals from Seattle to Basel by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Basel EuroAirport Swiss?

    Currently, August is the cheapest month in which you can book a flight from Seattle to Basel EuroAirport Swiss (average of $385). Flying from Seattle to Basel EuroAirport Swiss in May is currently the most expensive (average of $817). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Seattle to Basel

See prices for flight routes from nearby airports that may be better suited for you.
Portland to Basel flights

Top 2 airlines flying from Seattle to Basel

Discover the top 2 airlines that operate flights from Seattle to Basel. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$481Average$694FlexibilityNo cancel feeOn-time70%
LufthansaCheapest$497Average$723FlexibilityNo cancel feeOn-time76%

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