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$435+ 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 9/8. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SEA
ago. 23 — ago. 301
sáb. 8/23
sáb. 8/30
1 adult, Economy
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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 agosto 18, 2025.

Round-trip from

$682
(Trip.com)

One-way from

$435
(Kiwi.com)

Popular in

August

Cheapest in

October

Average price

$1,054
From Porto to Seattle/Tacoma Intl
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One-way flight from Porto to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 11% potential increase in price ($114 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($18 potential savings vs. average RT price).
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Average for round-trip flights in August 2025
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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 agosto 18, 2025.

This Trip.com deal was found by Cheapflights users on 8/16. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 9/48:05 amOPO - SEA
2 stops20h 35mMultiple Airlines
lun. 9/83:45 pmSEA - OPO
2 stops19h 00mMultiple Airlines
Deal found 8/16$682
This Kiwi.com deal was found by Cheapflights users on 8/16. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 10/96:05 pmOPO - SEA
1 stop36h 34mMultiple Airlines
mié. 10/151:02 pmSEA - OPO
2 stops21h 58mMultiple Airlines
Deal found 8/16$779
This United Airlines deal was found by Cheapflights users on 8/16. 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.
jue. 9/46:00 amOPO - SEA
1 stop13h 55mUnited Airlines
lun. 9/87:15 amSEA - OPO
1 stop18h 20mUnited Airlines
Deal found 8/16$821
This Air Canada deal was found by Cheapflights users on 8/16. 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 Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 10/96:00 amOPO - SEA
2 stops20h 36mAir Canada
mié. 10/1510:00 amSEA - OPO
2 stops24h 30mAir Canada
Deal found 8/16$824
This Mytrip deal was found by Cheapflights users on 8/16. 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.
mar. 9/306:20 amOPO - SEA
2 stops22h 20mMultiple Airlines
mar. 10/73:45 pmSEA - OPO
2 stops19h 05mMultiple Airlines
Deal found 8/16$826
This Lufthansa deal was found by Cheapflights users on 8/16. 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.
jue. 9/46:00 amOPO - SEA
2 stops20h 49mLufthansa
lun. 9/810:00 amSEA - OPO
2 stops15h 35mLufthansa
Deal found 8/16$828
This United Airlines deal was found by Cheapflights users on 8/16. 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.
lun. 12/1512:30 pmOPO - SEA
2 stops31h 15mUnited Airlines
mar. 1/65:07 amSEA - OPO
2 stops25h 38mUnited Airlines
Deal found 8/16$835
This Lufthansa deal was found by Cheapflights users on 8/16. 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.
mar. 9/306:00 amOPO - SEA
1 stop13h 55mLufthansa
mar. 10/72:20 pmSEA - OPO
1 stop17h 25mLufthansa
Deal found 8/16$839
This United Airlines deal was found by Cheapflights users on 8/16. 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.
mar. 9/306:00 amOPO - SEA
1 stop13h 55mUnited Airlines
mar. 10/76:35 amSEA - OPO
2 stops19h 10mUnited Airlines
Deal found 8/16$840

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 agosto 18, 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

jue. 9/4

8:05 am-8:40 pm

2 stops20h 35m

Seattle/Tacoma Intl

lun. 9/8

3:45 pm-6:45 pm

2 stops19h 00m

$682

PortoSeattle

OPO - SEA

OPOSEA

Porto

jue. 10/9

6:05 pm-10:39 pm

1 stop36h 34m

Seattle/Tacoma Intl

mié. 10/15

1:02 pm-7:00 pm

2 stops21h 58m

$779

PortoSeattle

OPO - SEA

OPOSEA

Porto

jue. 9/4

6:00 am-11:55 am

1 stop13h 55m

Seattle/Tacoma Intl

lun. 9/8

7:15 am-9:35 am

1 stop18h 20m

$821

PortoSeattle

OPO - SEA

OPOSEA

Porto

jue. 9/4

6:00 am-11:55 am

1 stop13h 55m

Seattle/Tacoma Intl

lun. 9/8

10:00 am-9:35 am

2 stops15h 35m

$822

PortoSeattle

OPO - SEA

OPOSEA

Porto

jue. 10/9

6:00 am-11:55 am

1 stop13h 55m

Seattle/Tacoma Intl

mié. 10/15

12:00 pm-9:45 am

1 stop13h 45m

$822

PortoSeattle

OPO - SEA

OPOSEA

Porto

jue. 10/9

6:00 am-6:36 pm

2 stops20h 36m

Seattle/Tacoma Intl

mié. 10/15

10:00 am-6:30 pm

2 stops24h 30m

$824

PortoSeattle

OPO - SEA

OPOSEA

Porto

lun. 9/8

7:25 pm-8:35 pm

3 stops57h 10m

$435

PortoSeattle

OPO - SEA

OPOSEA

Porto

mié. 10/1

7:15 am-10:08 pm

3 stops46h 53m

$460

PortoSeattle

OPO - SEA

OPOSEA

Porto

sáb. 11/1

8:00 pm-1:13 pm

3 stops48h 13m

$479

PortoSeattle

OPO - SEA

OPOSEA

Porto

sáb. 9/6

9:15 pm-12:30 am

3 stops59h 15m

$532

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/18

Showing 1-10 of 11 results
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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.

Cheapflights Insights

Everything you need to know about your flight from Porto to Seattle

How much does it cost to fly round-trip from Porto to Seattle?

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 13h 55m. Fly via United Airlines to get the fastest option. Porto and Seattle are separated by a distance of 5083 mi.

  • What is the cheapest airline to fly from Porto to Seattle round-trip?

    Currently priced at $794, KLM will fly you from Porto to Seattle and back. In addition to KLM, many other airlines offer competitively priced options for your trip. Users have found that KLM is 9% cheaper than the other options available to this destination.

  • 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.

  • What is the cheapest month to book a flight from Porto to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Porto to Seattle (average of $238). Flying from Porto to Seattle in June is currently the most expensive (average of $388). 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

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Ocean Shores
Lakewood
Lynnwood
Lacey
Leavenworth
Renton
Olympia
Puyallup
Kent
Cle Elum
Chehalis
Kirkland
Issaquah
Aberdeen
Shoreline
Federal Way
Shelton

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Porto to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
Lisbon to Seattle flights
Lisbon to Portland flights

Top airline flying from Porto to Seattle

Discover the top airline that operate flights from Porto to Seattle. 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 agosto 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$794Average$968FlexibilityNo cancel feeOn-time75%

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