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$436+ 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 3/4. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SEA
Dec 13 — Dec 201
Sat 12/13
Sat 12/20
1 adult, Economy
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Find flight deals from Porto to Seattle

Cheapest flights from Porto to Seattle
Explore the most affordable flight options available from Porto to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 13, 2025.

This lol.travel deal was found by Cheapflights users on 11/12. 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 lol.travel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/286:30 amOPO - SEA
2 stops23h 36mAir Canada
Wed 12/38:10 amSEA - OPO
2 stops21h 05mAir Canada
Deal found 11/12$817
This lol.travel deal was found by Cheapflights users on 11/12. 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 lol.travel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/286:30 amOPO - SEA
1 stop14h 50mLufthansa
Wed 12/33:10 pmSEA - OPO
1 stop14h 05mLufthansa
Deal found 11/12$848
This Gotogate deal was found by Cheapflights users on 11/12. 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 11/286:30 amOPO - SEA
2 stops23h 36mMultiple Airlines
Wed 12/33:10 pmSEA - OPO
1 stop14h 05mMultiple Airlines
Deal found 11/12$854
This United Airlines deal was found by Cheapflights users on 11/13. 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 11/2012:35 pmOPO - SEA
2 stops35h 40mUnited Airlines
Mon 11/2410:53 amSEA - OPO
2 stops14h 37mUnited Airlines
Deal found 11/13$878
This KLM deal was found by Cheapflights users on 11/12. 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 11/1911:15 amOPO - SEA
1 stop32h 30mKLM
Sun 11/232:05 pmSEA - OPO
1 stop36h 25mKLM
Deal found 11/12$879
This United Airlines deal was found by Cheapflights users on 11/11. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1812:30 pmOPO - SEA
2 stops42h 11mUnited Airlines
Sun 11/238:36 amSEA - OPO
2 stops16h 54mUnited Airlines
Deal found 11/11$881
This Delta deal was found by Cheapflights users on 11/12. 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 11/196:00 amOPO - SEA
2 stops24h 23mDelta
Sun 11/237:30 amSEA - OPO
2 stops19h 00mDelta
Deal found 11/12$884
This United Airlines deal was found by Cheapflights users on 11/12. 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 11/1912:35 pmOPO - SEA
1 stop18h 06mUnited Airlines
Sun 11/238:36 amSEA - OPO
2 stops16h 54mUnited Airlines
Deal found 11/12$886
This KLM deal was found by Cheapflights users on 11/11. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/184:10 pmOPO - SEA
1 stop27h 35mKLM
Sun 11/233:00 pmSEA - OPO
1 stop35h 30mKLM
Deal found 11/11$888

Cheap 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 November 13, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$817
(lol.travel)

One-way from

$436
(Kiwi.com)

Popular in

November

Cheapest in

April

Average price

$1,202
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. 3% potential increase in price ($31 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($25 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 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 November 13, 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

Fri 11/28

6:30 am-10:06 pm

2 stops23h 36m

Seattle/Tacoma Intl

Wed 12/3

8:10 am-1:15 pm

2 stops21h 05m

$817

PortoSeattle

OPO - SEA

OPOSEA

Porto

Fri 11/28

6:30 am-1:20 pm

1 stop14h 50m

Seattle/Tacoma Intl

Wed 12/3

3:10 pm-1:15 pm

1 stop14h 05m

$848

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 3/26

6:00 am-10:32 pm

2 stops23h 32m

Seattle/Tacoma Intl

Mon 3/30

12:25 pm-9:45 am

1 stop13h 20m

$853

PortoSeattle

OPO - SEA

OPOSEA

Porto

Fri 11/28

6:30 am-10:06 pm

2 stops23h 36m

Seattle/Tacoma Intl

Wed 12/3

3:10 pm-1:15 pm

1 stop14h 05m

$854

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 3/26

4:15 pm-1:10 pm

1 stop27h 55m

Seattle/Tacoma Intl

Mon 3/30

2:10 pm-3:45 pm

1 stop17h 35m

$873

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 3/4

8:45 am-10:18 pm

3 stops45h 33m

$436

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 1/8

7:00 pm-1:07 pm

3 stops50h 07m

$455

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 11/22

8:45 am-8:37 am

3 stops55h 52m

$488

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 1/10

2:45 pm-10:26 am

2 stops51h 41m

$512

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 1/7

8:05 pm-8:56 pm

3 stops56h 51m

$520

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/13

Showing 1-10 of 12 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 November.
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 14h 50m. Fly via Air Canada, Lufthansa, or United 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.

  • 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
SeaTac
Tacoma
Tukwila
Lakewood
Olympia
Ocean Shores
Lynnwood
Edmonds
Leavenworth
Renton
Kirkland
Lacey
Kent
Cle Elum
Marysville
Puyallup
Federal Way
Fife
Issaquah
Aberdeen

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