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$400+ 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 5/9. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SEA
Mar 17 — Mar 241
Mon 3/17
Mon 3/24
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 March 12, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$773
(British Airways)

One-way from

$400
(Kiwi.com)

Popular in

June

Cheapest in

October

Average price

$925
Provider with most accurate pricing for Porto-Seattle/Tacoma Intl flight deals.
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Provider most trusted by Cheapflights users for Porto-Seattle/Tacoma Intl flights.
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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. 22% potential increase in price ($259 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($52 potential savings vs. average RT price).
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Average for round-trip flights in March 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 March 12, 2025.

This British Airways deal was found by Cheapflights users on 3/11. 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/204:55 pmOPO - SEA
1 stop26h 25mBritish Airways
Tue 3/252:35 pmSEA - OPO
1 stop20h 05mBritish Airways
Deal found 3/11$768
This Delta deal was found by Cheapflights users on 3/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/206:15 amOPO - SEA
2 stops24h 17mDelta
Tue 3/259:41 amSEA - OPO
2 stops17h 49mDelta
Deal found 3/11$836
This United Airlines deal was found by Cheapflights users on 3/12. 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.
Sat 4/2612:35 pmOPO - SEA
1 stop17h 44mUnited Airlines
Sat 5/311:59 pmSEA - OPO
2 stops31h 41mUnited Airlines
Deal found 3/12$838
This Lufthansa deal was found by Cheapflights users on 3/12. 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 Lufthansa is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/76:00 amOPO - SEA
1 stop14h 25mLufthansa
Sun 4/136:50 pmSEA - OPO
2 stops20h 00mLufthansa
Deal found 3/12$869
This KLM deal was found by Cheapflights users on 3/12. 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.
Sat 4/266:55 pmOPO - SEA
1 stop29h 05mKLM
Sat 5/36:10 pmSEA - OPO
1 stop32h 30mKLM
Deal found 3/12$905
This Turkish Airlines deal was found by Cheapflights users on 3/11. 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 Turkish Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/1410:45 amOPO - SEA
1 stop38h 30mTurkish Airlines
Fri 7/47:10 pmSEA - OPO
1 stop35h 15mTurkish Airlines
Deal found 3/11$911
This Mytrip deal was found by Cheapflights users on 3/11. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/204:45 pmOPO - SEA
2 stops30h 35mMultiple Airlines
Tue 3/259:48 amSEA - OPO
3 stops39h 12mMultiple Airlines
Deal found 3/11$983
This Cheapflightsfares deal was found by Cheapflights users on 3/11. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/118:35 pmOPO - SEA
2 stops34h 34mIberia
Thu 5/228:20 pmSEA - OPO
2 stops27h 15mIberia
Deal found 3/11$3,517

Find flights from Porto to Seattle within your budget

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 March 12, 2025.

Fly from

Porto

Fly to

Seattle

Route

Depart

Return

Price

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 4/7

9:10 pm-11:10 am

1 stop22h 00m

Seattle/Tacoma Intl

Sun 4/13

1:30 pm-8:20 pm

1 stop22h 50m

$773

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 4/26

12:35 pm-10:19 pm

1 stop17h 44m

Seattle/Tacoma Intl

Sat 5/3

11:59 pm-3:40 pm

2 stops31h 41m

$838

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 4/9

6:20 am-4:00 pm

1 stop17h 40m

Seattle/Tacoma Intl

Tue 4/15

6:05 am-10:40 am

2 stops20h 35m

$844

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 4/7

6:00 am-12:25 pm

1 stop14h 25m

Seattle/Tacoma Intl

Sun 4/13

6:50 pm-10:50 pm

2 stops20h 00m

$869

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 4/26

6:55 pm-4:00 pm

1 stop29h 05m

Seattle/Tacoma Intl

Sat 5/3

6:10 pm-10:40 am

1 stop32h 30m

$905

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 6/14

10:45 am-5:15 pm

1 stop38h 30m

Seattle/Tacoma Intl

Fri 7/4

7:10 pm-2:25 pm

1 stop35h 15m

$911

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 4/9

4:55 pm-6:23 pm

3 stops33h 28m

Seattle/Tacoma Intl

Tue 4/15

3:45 pm-8:00 am

3 stops32h 15m

$999

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sun 5/11

8:35 pm-11:09 pm

2 stops34h 34m

Seattle/Tacoma Intl

Thu 5/22

8:20 pm-7:35 am

2 stops27h 15m

$3,517

PortoSeattle

OPO - SEA

OPOSEA

Porto

Fri 5/9

6:15 am-8:28 pm

3 stops46h 13m

$400

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 6/25

10:50 am-10:35 am

1 stop31h 45m

$661

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/11

Showing 1-10 of 14 results
1
2

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 March.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Porto-Seattle flight deals on Cheapflights vs. FlightHub >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 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 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.

Travel insights for flights from Porto to Seattle

Get recent, data-driven insights about flights from Porto to Seattle including ideal travel times, pricing trends, and more.

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 July is currently the most expensive (average of $411). 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.

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated March 12, 2025.
See what other customers who have flown with Delta, KLM and SWISS from Porto to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,953 reviews

Comfort

8.0

Overall

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Delta
8.0
Very good
7,953 reviews
Delta
8.0
Very good
7,953 reviews

Comfort

8.0

Overall

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

KLM
7.8
Good
1,320 reviews
Delta
8.0
Very good
7,953 reviews

Comfort

8.0

Overall

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

SWISS
7.5
Good
1,566 reviews
Delta
8.0
Very good
7,953 reviews

Comfort

8.0

Overall

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

United Airlines
7.4
Good
8,623 reviews
Delta
8.0
Very good
7,953 reviews

Comfort

8.0

Overall

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Turkish Airlines
7.3
Good
3,759 reviews
Delta
8.0
Very good
7,953 reviews

Comfort

8.0

Overall

8.0

Entertainment

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

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.

  • What are the cheapest airlines flying from Porto to Seattle round-trip?

    Currently priced at $773, British Airways will fly you from Porto to Seattle and back. In addition to British Airways, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from United Airlines and Delta - these airlines can fly you to your destination from $838 and $844, respectively. Users have found that British Airways is 14% cheaper than the other options available to this destination.

  • 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 Turkish Airlines ($661), United Airlines ($1,069), and Iberia ($1,073).

  • 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 July is currently the most expensive (average of $411). 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 Porto?

Book flights to Porto if you plan to visit one of these locations
SeaTac
Tukwila
Renton
Lacey
Ocean Shores
Tacoma
Leavenworth
Federal Way
Lakewood
Centralia
Olympia
Cle Elum
Mukilteo
Aberdeen
Issaquah
Shoreline
Lynnwood
Shelton
Silverdale
Redmond

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.
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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 March 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$756Average$870FlexibilityNo cancel feeOn-time75%
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