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Basel

$378+ 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 4/20. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BSL
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
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 January 26, 2026.

This KLM deal was found by Cheapflights users on 1/25. 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.
Tue 2/241:40 pm
SEA
-
BSL
1 stop15h 10m
KLM
Fri 3/66:05 am
BSL
-
SEA
1 stop14h 30m
KLM
Deal found 1/25$483
This oojo deal was found by Cheapflights users on 1/25. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/247:15 am
SEA
-
BSL
2 stops22h 50m
British Airways
Fri 3/63:55 pm
BSL
-
SEA
2 stops41h 29m
British Airways
Deal found 1/25$486
This Delta deal was found by Cheapflights users on 1/25. 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.
Mon 2/237:30 am
SEA
-
BSL
2 stops17h 20m
Delta
Mon 3/96:05 am
BSL
-
SEA
1 stop14h 30m
Delta
Deal found 1/25$487
This KLM deal was found by Cheapflights users on 1/26. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/263:05 pm
SEA
-
BSL
1 stop34h 35m
KLM
Sun 3/15:55 pm
BSL
-
SEA
1 stop26h 40m
KLM
Deal found 1/26$489
This Delta deal was found by Cheapflights users on 1/25. 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.
Wed 3/117:15 am
SEA
-
BSL
2 stops19h 25m
Delta
Wed 3/186:05 am
BSL
-
SEA
1 stop14h 30m
Delta
Deal found 1/25$493
This KLM deal was found by Cheapflights users on 1/25. 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.
Mon 2/237:30 am
SEA
-
BSL
2 stops17h 20m
Multiple Airlines
Mon 3/96:05 am
BSL
-
SEA
2 stops18h 36m
Multiple Airlines
Deal found 1/25$494
This Delta deal was found by Cheapflights users on 1/25. 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.
Mon 3/99:40 am
SEA
-
BSL
2 stops20h 10m
Delta
Tue 3/176:05 am
BSL
-
SEA
2 stops20h 21m
Delta
Deal found 1/25$497
This Air France deal was found by Cheapflights users on 1/25. 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 2/263:05 pm
SEA
-
BSL
1 stop17h 20m
Air France
Sun 3/16:05 am
BSL
-
SEA
2 stops19h 43m
Air France
Deal found 1/25$499
This Mytrip deal was found by Cheapflights users on 1/25. 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.
Thu 2/265:37 am
SEA
-
BSL
2 stops28h 28m
British Airways
Sun 3/16:50 pm
BSL
-
SEA
2 stops37h 14m
British Airways
Deal found 1/25$512
This Cheapflightsfares deal was found by Cheapflights users on 1/24. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/161:45 pm
SEA
-
BSL
2 stops14h 55m
Multiple Airlines
Thu 10/18:15 am
BSL
-
SEA
2 stops15h 01m
Multiple Airlines
Deal found 1/24$530
This FlightHub deal was found by Cheapflights users on 1/25. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/156:50 pm
SEA
-
BSL
1 stop15h 50m
Lufthansa
Tue 9/228:15 am
BSL
-
SEA
2 stops15h 01m
Lufthansa
Deal found 1/25$536

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 January 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
1 star

Round-trip from

$483
(KLM)

One-way from

$378
(Kiwi.com)

Popular in

May

Cheapest in

August

Average price

$524
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. 35% potential increase in price ($461 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 14% potential price decrease ($106 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
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 January 26, 2026.
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

Tue 2/24

1:40 pm-1:50 pm

1 stop15h 10m

Basel EuroAirport Swiss

Fri 3/6

6:05 am-11:35 am

1 stop14h 30m

$483

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Thu 2/26

7:15 am-3:05 pm

2 stops22h 50m

Basel EuroAirport Swiss

Sun 3/1

4:25 pm-4:55 pm

1 stop33h 30m

$483

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 3/9

3:10 pm-1:50 pm

1 stop14h 40m

Basel EuroAirport Swiss

Tue 3/17

5:55 pm-12:35 pm

1 stop26h 40m

$483

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Tue 2/24

7:15 am-3:05 pm

2 stops22h 50m

Basel EuroAirport Swiss

Fri 3/6

3:55 pm-11:30 am

1 stop28h 35m

$483

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 2/23

7:30 am-9:50 am

2 stops17h 20m

Basel EuroAirport Swiss

Mon 3/9

6:05 am-12:35 pm

1 stop14h 30m

$487

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Thu 2/26

3:05 pm-10:40 am

1 stop34h 35m

Basel EuroAirport Swiss

Sun 3/1

11:15 am-11:35 am

1 stop33h 20m

$489

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 2/23

7:30 am-9:50 am

2 stops17h 20m

Basel EuroAirport Swiss

Mon 3/9

6:05 am-4:41 pm

2 stops18h 36m

$494

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 3/9

9:40 am-1:50 pm

2 stops20h 10m

Basel EuroAirport Swiss

Tue 3/17

6:05 am-6:26 pm

2 stops20h 21m

$497

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 7/15

6:50 pm-7:40 pm

1 stop15h 50m

Basel EuroAirport Swiss

Mon 7/27

8:15 pm-4:59 pm

1 stop29h 44m

$796

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Sun 2/22

3:10 pm-12:30 pm

1 stop12h 20m

Basel EuroAirport Swiss

Sun 3/1

9:50 am-10:16 pm

2 stops21h 26m

$852

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/24

Showing 1-10 of 15 results
1
2
  • Most accurate provider: When it comes to deals on Seattle-Basel EuroAirport Swiss flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Basel EuroAirport Swiss flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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 $1,983). 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.

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 January 26, 2026.
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
7,747 reviews

Crew

7.6

Boarding

7.0

Food

6.3

Entertainment

6.4

Overall

6.8

Comfort

6.8

Reviews

1 / 20
6.0
Good

Anonymous,Dec 2025

SFO - MUC

The coordination between United and Lufthansa teams is poor and confusing.
Lufthansa
6.8
Okay
7,747 reviews
Lufthansa
6.8
Okay
7,747 reviews

Crew

7.6

Boarding

7.0

Food

6.3

Entertainment

6.4

Overall

6.8

Comfort

6.8

Reviews

1 / 20
6.0
Good

Anonymous,Dec 2025

SFO - MUC

The coordination between United and Lufthansa teams is poor and confusing.
British Airways
6.7
Okay
7,701 reviews
Lufthansa
6.8
Okay
7,747 reviews

Crew

7.6

Boarding

7.0

Food

6.3

Entertainment

6.4

Overall

6.8

Comfort

6.8

Reviews

1 / 20
6.0
Good

Anonymous,Dec 2025

SFO - MUC

The coordination between United and Lufthansa teams is poor and confusing.

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 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 40m. 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 43% 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 $1,983). 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 January 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$467Average$729FlexibilityNo cancel feeOn-time70%
LufthansaCheapest$483Average$723FlexibilityNo cancel feeOn-time76%

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