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$371+ Cheap flights from Porto (OPO) to Seattle (SEA)

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 5/5. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SEA
Jan 19 — Jan 261
Mon 1/19
Mon 1/26
1 adult, Economy
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Cheap flight deals from Porto to Seattle

Best flights from Porto to Seattle
Discover carefully curated flight deals from Porto to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated December 20, 2025.

This Mytrip deal was found by Cheapflights users on 12/19. 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.
Tue 2/39:55 pmOPO - SEA
3 stops27h 05mMultiple Airlines
Tue 2/102:35 pmSEA - OPO
3 stops22h 40mMultiple Airlines
Deal found 12/19$668
This British Airways deal was found by Cheapflights users on 12/19. 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.
Fri 2/138:20 amOPO - SEA
2 stops23h 09mBritish Airways
Tue 2/171:25 pmSEA - OPO
1 stop20h 20mBritish Airways
Deal found 12/19$753
This American Airlines deal was found by Cheapflights users on 12/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/2212:25 pmOPO - SEA
2 stops31h 05mAmerican Airlines
Sun 1/257:00 amSEA - OPO
2 stops16h 40mAmerican Airlines
Deal found 12/18$770
This Iberia deal was found by Cheapflights users on 12/19. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/38:20 amOPO - SEA
2 stops21h 27mIberia
Tue 2/106:00 amSEA - OPO
2 stops17h 40mIberia
Deal found 12/19$771
This Delta deal was found by Cheapflights users on 12/19. 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.
Tue 2/35:00 amOPO - SEA
1 stop14h 40mDelta
Tue 2/101:40 pmSEA - OPO
1 stop12h 50mDelta
Deal found 12/19$806
This United Airlines deal was found by Cheapflights users on 12/19. 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.
Thu 5/216:00 amOPO - SEA
2 stops22h 10mUnited Airlines
Mon 5/256:50 amSEA - OPO
1 stop16h 05mUnited Airlines
Deal found 12/19$888
This Mytrip deal was found by Cheapflights users on 12/19. 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.
Fri 2/136:00 amOPO - SEA
2 stops24h 16mMultiple Airlines
Tue 2/178:00 pmSEA - OPO
3 stops31h 40mMultiple Airlines
Deal found 12/19$744
This Delta deal was found by Cheapflights users on 12/19. 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.
Fri 2/135:00 amOPO - SEA
1 stop14h 40mDelta
Tue 2/178:30 amSEA - OPO
2 stops18h 00mDelta
Deal found 12/19$806

Find flight deals from Porto to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from Porto (OPO) to Seattle (SEA). 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 December 20, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$668
(Mytrip)

One-way from

$371
(Kiwi.com)

Popular in

July

Cheapest in

April

Average price

$1,038
Provider with most accurate pricing for Porto-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Porto-Seattle/Tacoma Intl flights.
Search Deals
From Porto to Seattle/Tacoma Intl
Search Deals
One-way flight from Porto to Seattle/Tacoma Intl
Search Deals
Highest demand for flights based on searches. 6% potential increase in price ($71 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($34 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Porto to Seattle 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 December 20, 2025.
Use the filters below to find and compare flights from Porto to Seattle that are best for you.

Fly from

Porto

Fly to

Seattle

Route

Depart

Return

Price

PortoSeattle

OPO - SEA

OPOSEA

Porto

Tue 2/3

9:55 pm-5:00 pm

3 stops27h 05m

Seattle/Tacoma Intl

Tue 2/10

2:35 pm-9:15 pm

3 stops22h 40m

$668

PortoSeattle

OPO - SEA

OPOSEA

Porto

Fri 2/13

6:00 am-10:16 pm

2 stops24h 16m

Seattle/Tacoma Intl

Tue 2/17

8:00 pm-11:40 am

3 stops31h 40m

$744

PortoSeattle

OPO - SEA

OPOSEA

Porto

Fri 2/13

8:20 am-11:29 pm

2 stops23h 09m

Seattle/Tacoma Intl

Tue 2/17

1:25 pm-5:45 pm

1 stop20h 20m

$753

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 1/22

12:25 pm-11:30 am

2 stops31h 05m

Seattle/Tacoma Intl

Sun 1/25

7:00 am-7:40 am

2 stops16h 40m

$770

PortoSeattle

OPO - SEA

OPOSEA

Porto

Tue 2/3

8:20 am-9:47 pm

2 stops21h 27m

Seattle/Tacoma Intl

Tue 2/10

6:00 am-7:40 am

2 stops17h 40m

$771

PortoSeattle

OPO - SEA

OPOSEA

Porto

Tue 2/3

5:00 am-11:40 am

1 stop14h 40m

Seattle/Tacoma Intl

Tue 2/10

1:40 pm-10:30 am

1 stop12h 50m

$806

PortoSeattle

OPO - SEA

OPOSEA

Porto

Fri 2/13

5:00 am-11:40 am

1 stop14h 40m

Seattle/Tacoma Intl

Tue 2/17

8:30 am-10:30 am

2 stops18h 00m

$806

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 5/21

6:00 am-8:10 pm

2 stops22h 10m

Seattle/Tacoma Intl

Mon 5/25

6:50 am-6:55 am

1 stop16h 05m

$888

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 5/30

1:30 pm-12:30 pm

2 stops31h 00m

$441

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sun 4/19

3:10 pm-9:02 am

3 stops49h 52m

$449

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/20

Showing 1-10 of 13 results
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Compare providers for flights from Porto to Seattle

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 Porto to Seattle in December.
ProviderPrice AccuracyTrust Score*
eDreamsPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star

*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 Porto-Seattle flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Porto-Seattle flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Porto-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Porto-Seattle 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 Porto-Seattle 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 Porto to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Porto 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.

Related info for your journey

Find useful and relevant information for your journey from Porto to Seattle. 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 Porto to Seattle?

    There are many flights that can get you from Porto to Seattle in 23h 09m. Fly via British Airways or American Airlines to get the fastest option. Porto and Seattle are separated by a distance of 5083 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines to fly from Porto to Seattle one-way?

    The cheapest airlines for a one-way flight from Porto to Seattle are Delta ($707), Air France ($717), and KLM ($722).

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

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

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

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

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

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

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Tacoma
SeaTac
Lakewood
Ocean Shores
Olympia
Edmonds
Lynnwood
Renton
Puyallup
Kirkland
Kent
Tukwila
Cle Elum
Marysville
Leavenworth
Fife
Aberdeen
Shoreline
Centralia
Federal Way

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