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$516+ 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 10/14. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SEA
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
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 June 12, 2025.

Round-trip from

$825
(lol.travel)

One-way from

$516
(Mytrip)

Popular in

July

Cheapest in

October

Average price

$865
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. 6% potential increase in price ($61 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($20 potential savings vs. average RT price).
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Average for round-trip flights in June 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 June 12, 2025.

This flugladen.de deal was found by Cheapflights users on 6/12. 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 flugladen.de is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/198:20 pmOPO - SEA
1 stop23h 20mKLM
Mon 6/235:35 pmSEA - OPO
1 stop33h 05mKLM
Deal found 6/12$779
This British Airways deal was found by Cheapflights users on 6/10. 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 6/199:55 amOPO - SEA
1 stop16h 25mBritish Airways
Mon 6/238:20 pmSEA - OPO
1 stop15h 30mBritish Airways
Deal found 6/10$783
This Delta deal was found by Cheapflights users on 6/12. 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.
Thu 6/196:30 amOPO - SEA
2 stops25h 23mDelta
Mon 6/235:35 pmSEA - OPO
1 stop16h 20mDelta
Deal found 6/12$787
This lol.travel deal was found by Cheapflights users on 6/10. 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.
Tue 9/306:00 amOPO - SEA
1 stop13h 55mLufthansa
Mon 12/222:00 pmSEA - OPO
1 stop16h 55mLufthansa
Deal found 6/10$825
This United Airlines deal was found by Cheapflights users on 6/10. 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 10/16:00 amOPO - SEA
1 stop13h 55mUnited Airlines
Thu 12/2511:50 pmSEA - OPO
2 stops30h 55mUnited Airlines
Deal found 6/10$846
This Trip.com deal was found by Cheapflights users on 6/10. 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.
Thu 6/198:05 amOPO - SEA
2 stops20h 35mMultiple Airlines
Mon 6/233:45 pmSEA - OPO
2 stops19h 00mMultiple Airlines
Deal found 6/10$855
This Air Canada deal was found by Cheapflights users on 6/10. 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.
Mon 9/2912:10 pmOPO - SEA
2 stops42h 06mAir Canada
Thu 12/258:20 pmSEA - OPO
2 stops34h 25mAir Canada
Deal found 6/10$882
This Iberia deal was found by Cheapflights users on 6/10. 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 9/3010:00 pmOPO - SEA
2 stops30h 09mIberia
Mon 12/2210:20 amSEA - OPO
2 stops25h 40mIberia
Deal found 6/10$902
This American Airlines deal was found by Cheapflights users on 6/10. 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.
Mon 9/2912:20 pmOPO - SEA
2 stops28h 59mAmerican Airlines
Tue 12/231:37 amSEA - OPO
2 stops46h 03mAmerican Airlines
Deal found 6/10$1,021
This FlightHub deal was found by Cheapflights users on 6/11. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/610:50 amOPO - SEA
1 stop31h 45mTurkish Airlines
Wed 8/207:10 pmSEA - OPO
1 stop30h 35mTurkish Airlines
Deal found 6/11$1,053
This SWISS deal was found by Cheapflights users on 6/10. 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 SWISS is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/297:20 pmOPO - SEA
2 stops31h 16mSWISS
Fri 12/1911:05 amSEA - OPO
2 stops22h 25mSWISS
Deal found 6/10$2,208

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 June 12, 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 9/30

6:00 am-11:55 am

1 stop13h 55m

Seattle/Tacoma Intl

Mon 12/22

2:00 pm-2:55 pm

1 stop16h 55m

$825

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 10/1

6:00 am-11:55 am

1 stop13h 55m

Seattle/Tacoma Intl

Thu 12/25

11:50 pm-2:45 pm

2 stops30h 55m

$846

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 9/29

12:10 pm-10:16 pm

2 stops42h 06m

Seattle/Tacoma Intl

Thu 12/25

8:20 pm-2:45 pm

2 stops34h 25m

$882

PortoSeattle

OPO - SEA

OPOSEA

Porto

Tue 9/30

10:00 pm-8:09 pm

2 stops30h 09m

Seattle/Tacoma Intl

Mon 12/22

10:20 am-8:00 pm

2 stops25h 40m

$902

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 9/29

4:20 pm-10:56 am

2 stops26h 36m

Seattle/Tacoma Intl

Wed 12/24

7:20 am-10:50 am

2 stops19h 30m

$924

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sun 7/27

5:00 am-3:50 pm

1 stop18h 50m

Seattle/Tacoma Intl

Sun 8/3

5:40 pm-10:15 pm

1 stop20h 35m

$1,008

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 9/29

12:20 pm-9:19 am

2 stops28h 59m

Seattle/Tacoma Intl

Tue 12/23

1:37 am-7:40 am

2 stops46h 03m

$1,021

PortoSeattle

OPO - SEA

OPOSEA

Porto

Wed 8/6

10:50 am-10:35 am

1 stop31h 45m

Seattle/Tacoma Intl

Wed 8/20

7:10 pm-9:45 am

1 stop30h 35m

$1,053

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sun 7/27

6:25 am-4:25 pm

3 stops42h 00m

Seattle/Tacoma Intl

Sun 8/3

3:45 pm-11:15 pm

3 stops23h 30m

$1,115

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 9/29

7:20 pm-6:36 pm

2 stops31h 16m

Seattle/Tacoma Intl

Fri 12/19

11:05 am-5:30 pm

2 stops22h 25m

$2,208

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

Showing 1-10 of 15 results
1
2

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

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 June 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
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

Entertainment

7.9

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
7,946 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

Entertainment

7.9

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
1,358 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

Entertainment

7.9

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!
SWISS
7.5
Good
1,623 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

Entertainment

7.9

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
8,790 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

Entertainment

7.9

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!
Turkish Airlines
7.3
Good
3,848 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

Entertainment

7.9

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 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 $825, Lufthansa will fly you from Porto to Seattle and back. In addition to Lufthansa, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from United Airlines and Air Canada - these airlines can fly you to your destination from $846 and $882, respectively. Users have found that Lufthansa is 2% 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 ($672), British Airways ($732), and Iberia ($733).

  • 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 $391). 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
Tacoma
Lakewood
Ocean Shores
Lacey
Leavenworth
Federal Way
Lynnwood
Olympia
Shoreline
Kent
Cle Elum
Centralia
Kirkland
Aberdeen
Renton
Shelton
Silverdale
Issaquah

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 June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$756Average$848FlexibilityNo cancel feeOn-time75%

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