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$481+ Cheap flights from Seattle (SEA) to Basel EuroAirport Swiss (BSL)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 1/24. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BSL
ene. 11 — ene. 181
dom. 1/11
dom. 1/18
1 adult, Economy
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Cheap 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 diciembre 12, 2025.

This Air France deal was found by Cheapflights users on 12/11. 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.
vie. 12/263:05 pmSEA - BSL
1 stop34h 35mAir France
lun. 1/511:15 amBSL - SEA
1 stop33h 35mAir France
Deal found 12/11$1,182
This Ovago deal was found by Cheapflights users on 12/10. 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 Ovago is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 12/267:00 amSEA - BSL
2 stops18h 05mLufthansa
lun. 1/52:20 pmBSL - SEA
2 stops39h 37mLufthansa
Deal found 12/10$1,320
This Air France deal was found by Cheapflights users on 12/11. 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.
jue. 12/253:05 pmSEA - BSL
1 stop34h 35mAir France
jue. 1/16:05 amBSL - SEA
1 stop14h 45mAir France
Deal found 12/11$1,380
This KLM deal was found by Cheapflights users on 12/10. 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.
lun. 12/222:05 pmSEA - BSL
1 stop14h 45mKLM
mar. 12/306:05 amBSL - SEA
1 stop14h 45mKLM
Deal found 12/10$2,026
This Delta deal was found by Cheapflights users on 12/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 12/227:10 amSEA - BSL
2 stops18h 30mDelta
mar. 12/306:05 amBSL - SEA
2 stops19h 55mDelta
Deal found 12/11$2,047

Find 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 diciembre 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$480
(FlightHub)

Popular in

May

Cheapest in

August

Average price

$611
Provider with most accurate pricing for Seattle/Tacoma Intl-Basel EuroAirport Swiss flight deals.
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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
Highest demand for flights based on searches. 34% potential increase in price ($366 potential increase over avg. RT price).
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Cheapest flight prices on average. 9% potential price decrease ($60 potential savings vs. average RT price).
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Average for round-trip flights in December 2025
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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 diciembre 12, 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

jue. 2/19

1:40 pm-1:50 pm

1 stop15h 10m

Basel EuroAirport Swiss

dom. 3/15

11:15 am-12:35 pm

1 stop33h 20m

$481

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

sáb. 1/24

1:40 pm-1:50 pm

1 stop15h 10m

Basel EuroAirport Swiss

sáb. 1/31

6:05 am-11:50 am

1 stop14h 45m

$481

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

sáb. 2/21

1:40 pm-1:50 pm

1 stop15h 10m

Basel EuroAirport Swiss

sáb. 3/14

11:15 am-12:35 pm

1 stop33h 20m

$481

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

mié. 2/25

7:15 am-2:55 pm

2 stops22h 40m

Basel EuroAirport Swiss

sáb. 3/14

11:10 am-5:55 pm

1 stop14h 45m

$482

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

sáb. 1/24

8:04 am-3:35 pm

2 stops22h 31m

Basel EuroAirport Swiss

sáb. 1/31

7:10 am-4:55 pm

1 stop18h 45m

$482

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

dom. 2/22

3:10 pm-7:40 pm

1 stop19h 30m

Basel EuroAirport Swiss

dom. 3/15

9:50 am-2:20 pm

1 stop12h 30m

$484

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

jue. 2/19

7:10 am-9:50 am

2 stops17h 40m

Basel EuroAirport Swiss

sáb. 3/14

6:05 am-12:35 pm

1 stop14h 30m

$485

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 2/23

6:50 pm-6:15 pm

1 stop14h 25m

Basel EuroAirport Swiss

dom. 3/15

4:25 pm-5:55 pm

1 stop33h 30m

$486

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

mié. 2/18

6:50 pm-10:15 am

1 stop30h 25m

Basel EuroAirport Swiss

dom. 3/15

6:50 pm-5:55 pm

1 stop31h 05m

$486

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

lun. 2/23

6:50 pm-9:35 pm

1 stop17h 45m

Basel EuroAirport Swiss

sáb. 3/14

7:10 am-5:55 pm

1 stop18h 45m

$486

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

Showing 1-10 of 12 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 December.
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 diciembre 12, 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 diciembre 12, 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
7,626 reviews

Entertainment

6.4

Overall

6.8

Comfort

6.8

Boarding

7.0

Crew

7.6

Food

6.3

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
7,626 reviews
Lufthansa
6.8
Okay
7,626 reviews

Entertainment

6.4

Overall

6.8

Comfort

6.8

Boarding

7.0

Crew

7.6

Food

6.3

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
7,571 reviews
Lufthansa
6.8
Okay
7,626 reviews

Entertainment

6.4

Overall

6.8

Comfort

6.8

Boarding

7.0

Crew

7.6

Food

6.3

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 Air France, KLM, and British Airways fly from Seattle to Basel EuroAirport Swiss in about 15h 10m. The time it takes to get you to your destination can typically vary by up to 7h 30m. 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 $467, 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 34% 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

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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 diciembre 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$467Average$694FlexibilityNo cancel feeOn-time70%
LufthansaCheapest$483Average$659FlexibilityNo cancel feeOn-time76%

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