HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Basel

$289+ 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 12/23. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — BSL
Aug 2 — Aug 91
Sat 8/2
Sat 8/9
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Seattle to Basel with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

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 July 28, 2025.

Round-trip from

$452
(British Airways)

One-way from

$289
(Travelocity)

Popular in

June

Cheapest in

August

Average price

$741
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. 16% potential increase in price ($137 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($31 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2025
Search Deals

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 July 28, 2025.

This British Airways deal was found by Cheapflights users on 7/27. 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/176:50 pmSEA - BSL
1 stop30h 25mBritish Airways
Fri 12/511:15 amBSL - SEA
1 stop14h 40mBritish Airways
Deal found 7/27$452
This Delta deal was found by Cheapflights users on 7/27. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/191:55 pmSEA - BSL
1 stop34h 55mDelta
Tue 12/211:15 amBSL - SEA
1 stop33h 35mDelta
Deal found 7/27$470
This KLM deal was found by Cheapflights users on 7/28. 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.
Sun 9/76:45 pmSEA - BSL
1 stop29h 45mMultiple Airlines
Wed 9/2410:10 amBSL - SEA
1 stop14h 55mMultiple Airlines
Deal found 7/28$500
This KLM deal was found by Cheapflights users on 7/27. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/105:40 pmSEA - BSL
1 stop30h 55mKLM
Wed 9/176:25 pmBSL - SEA
1 stop26h 20mKLM
Deal found 7/27$512
This United Airlines deal was found by Cheapflights users on 7/27. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/193:10 pmSEA - BSL
1 stop19h 30mUnited Airlines
Tue 12/29:45 amBSL - SEA
3 stops24h 14mUnited Airlines
Deal found 7/27$521
This Lufthansa deal was found by Cheapflights users on 7/27. 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 Lufthansa is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/193:10 pmSEA - BSL
1 stop19h 30mLufthansa
Mon 12/110:35 amBSL - SEA
1 stop34h 35mLufthansa
Deal found 7/27$523

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 July 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

Mon 11/17

6:50 pm-9:35 pm

1 stop17h 45m

Basel EuroAirport Swiss

Thu 12/4

3:40 pm-4:55 pm

1 stop34h 15m

$452

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 11/19

1:55 pm-9:50 am

1 stop34h 55m

Basel EuroAirport Swiss

Tue 12/2

11:15 am-11:50 am

1 stop33h 35m

$470

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Sun 9/7

6:45 pm-9:30 am

1 stop29h 45m

Basel EuroAirport Swiss

Wed 9/24

10:10 am-4:05 pm

1 stop14h 55m

$500

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 9/10

5:40 pm-9:35 am

1 stop30h 55m

Basel EuroAirport Swiss

Wed 9/17

6:25 pm-11:45 am

1 stop26h 20m

$512

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 11/19

3:10 pm-7:40 pm

1 stop19h 30m

Basel EuroAirport Swiss

Tue 12/2

9:45 am-12:59 am

3 stops24h 14m

$521

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Wed 11/19

3:10 pm-7:40 pm

1 stop19h 30m

Basel EuroAirport Swiss

Mon 12/1

10:35 am-12:10 pm

1 stop34h 35m

$523

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Tue 12/23

1:25 pm-3:05 pm

1 stop16h 40m

$289

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Tue 12/23

10:20 am-3:05 pm

2 stops19h 45m

$293

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Thu 11/6

9:32 pm-1:40 pm

3 stops55h 08m

$300

SeattleBasel

SEA - BSL

SEABSL

Seattle/Tacoma Intl

Mon 11/3

1:55 pm-1:50 pm

1 stop14h 55m

$302

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/27

Showing 1-10 of 13 results
1
2

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, January is the cheapest month in which you can book a flight from Seattle to Basel EuroAirport Swiss (average of $545). Flying from Seattle to Basel EuroAirport Swiss in June is currently the most expensive (average of $1,132). 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 July 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 24% on your trip compared to booking a flight in the afternoon.

How much does it cost to fly round-trip from Seattle to Basel EuroAirport Swiss?

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 July 28, 2025.
Read reviews from past customers who have flown Delta, KLM, and Air France 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.
Delta
8.0
Very good
7,975 reviews

Comfort

7.9

Entertainment

7.9

Crew

8.5

Food

7.3

Overall

8.0

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Delta
8.0
Very good
7,975 reviews
Delta
8.0
Very good
7,975 reviews

Comfort

7.9

Entertainment

7.9

Crew

8.5

Food

7.3

Overall

8.0

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
KLM
7.8
Good
1,383 reviews
Delta
8.0
Very good
7,975 reviews

Comfort

7.9

Entertainment

7.9

Crew

8.5

Food

7.3

Overall

8.0

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Air France
7.5
Good
1,465 reviews
Delta
8.0
Very good
7,975 reviews

Comfort

7.9

Entertainment

7.9

Crew

8.5

Food

7.3

Overall

8.0

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
United Airlines
7.4
Good
8,892 reviews
Delta
8.0
Very good
7,975 reviews

Comfort

7.9

Entertainment

7.9

Crew

8.5

Food

7.3

Overall

8.0

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,975 reviews

Comfort

7.9

Entertainment

7.9

Crew

8.5

Food

7.3

Overall

8.0

Boarding

8.2

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

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.

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

    British Airways, at $452, was found to be the cheapest airline from Seattle to Basel EuroAirport Swiss.Alternate airlines to your destination round-trip include Delta and KLM. You may be able to fly from Seattle to Basel EuroAirport Swiss for 34% less than the average price by searching for these airlines.

  • What are the cheapest airlines to fly from Seattle to Basel EuroAirport Swiss one-way?

    One-way options have recently been found by users for as low as $289 on British Airways. Other airlines that offer cheap prices include American Airlines from $293 and Air France from $302 one-way.

  • 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, January is the cheapest month in which you can book a flight from Seattle to Basel EuroAirport Swiss (average of $545). Flying from Seattle to Basel EuroAirport Swiss in June is currently the most expensive (average of $1,132). 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

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

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 airline flying from Seattle to Basel

Discover the top airline 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 July 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$443Average$694FlexibilityNo cancel feeOn-time70%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.