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$421+ 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 10/6. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SEA
Jul 8 — Jul 151
Tue 7/8
Tue 7/15
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 July 3, 2025.

Round-trip from

$820
(Trip.com)

One-way from

$421
(Kiwi.com)

Popular in

July

Cheapest in

October

Average price

$1,053
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 July 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 July 3, 2025.

This Trip.com deal was found by Cheapflights users on 7/2. 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 8/286:30 amOPO - SEA
2 stops22h 10mMultiple Airlines
Mon 9/13:45 pmSEA - OPO
2 stops17h 45mMultiple Airlines
Deal found 7/2$820
This United Airlines deal was found by Cheapflights users on 7/3. 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 8/2812:10 pmOPO - SEA
1 stop16h 31mUnited Airlines
Mon 9/17:20 amSEA - OPO
1 stop18h 15mUnited Airlines
Deal found 7/3$875
This Booking.com deal was found by Cheapflights users on 7/2. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/2812:10 pmOPO - SEA
1 stop16h 31mAir Canada
Mon 9/110:00 amSEA - OPO
2 stops15h 35mAir Canada
Deal found 7/2$876
This Lufthansa deal was found by Cheapflights users on 7/3. 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.
Thu 8/2812:10 pmOPO - SEA
2 stops38h 26mLufthansa
Mon 9/110:00 amSEA - OPO
2 stops15h 35mLufthansa
Deal found 7/3$886
This Delta deal was found by Cheapflights users on 7/2. 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.
Sun 8/2411:25 amOPO - SEA
1 stop36h 30mDelta
Sun 8/315:40 pmSEA - OPO
1 stop13h 55mDelta
Deal found 7/2$934
This British Airways deal was found by Cheapflights users on 7/3. 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 8/289:55 amOPO - SEA
1 stop33h 40mBritish Airways
Mon 9/13:43 pmSEA - OPO
2 stops20h 07mBritish Airways
Deal found 7/3$1,044
This KLM deal was found by Cheapflights users on 7/3. 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 8/29:20 amOPO - SEA
1 stop16h 15mKLM
Sat 8/91:30 pmSEA - OPO
1 stop18h 00mKLM
Deal found 7/3$1,203

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 July 3, 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

Thu 8/28

6:30 am-8:40 pm

2 stops22h 10m

Seattle/Tacoma Intl

Mon 9/1

3:45 pm-5:30 pm

2 stops17h 45m

$820

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 8/28

12:10 pm-8:41 pm

1 stop16h 31m

Seattle/Tacoma Intl

Mon 9/1

7:20 am-9:35 am

1 stop18h 15m

$875

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 8/28

12:10 pm-8:41 pm

1 stop16h 31m

Seattle/Tacoma Intl

Mon 9/1

10:00 am-9:35 am

2 stops15h 35m

$876

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 8/28

12:10 pm-6:36 pm

2 stops38h 26m

Seattle/Tacoma Intl

Mon 9/1

10:00 am-9:35 am

2 stops15h 35m

$886

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sun 8/24

11:25 am-3:55 pm

1 stop36h 30m

Seattle/Tacoma Intl

Sun 8/31

5:40 pm-3:35 pm

1 stop13h 55m

$934

PortoSeattle

OPO - SEA

OPOSEA

Porto

Thu 8/28

9:55 am-11:35 am

1 stop33h 40m

Seattle/Tacoma Intl

Mon 9/1

3:43 pm-7:50 pm

2 stops20h 07m

$1,044

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sat 8/2

9:20 am-5:35 pm

1 stop16h 15m

Seattle/Tacoma Intl

Sat 8/9

1:30 pm-3:30 pm

1 stop18h 00m

$1,203

PortoSeattle

OPO - SEA

OPOSEA

Porto

Mon 10/6

6:10 am-10:22 am

2 stops36h 12m

$421

PortoSeattle

OPO - SEA

OPOSEA

Porto

Tue 10/14

10:50 am-5:15 pm

1 stop38h 25m

$686

PortoSeattle

OPO - SEA

OPOSEA

Porto

Sun 9/21

8:15 am-8:09 pm

2 stops19h 54m

$751

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/1

Showing 1-10 of 15 results
1
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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.

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 July 3, 2025.
Peruse reviews from past customers who have flown with Delta, KLM, and United Airlines from Porto to Seattle to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,970 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Overall

8.0

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
7,970 reviews
Delta
8.0
Very good
7,970 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Overall

8.0

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
1,366 reviews
Delta
8.0
Very good
7,970 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Overall

8.0

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
8,845 reviews
Delta
8.0
Very good
7,970 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Overall

8.0

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
3,895 reviews
Delta
8.0
Very good
7,970 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Overall

8.0

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!
Air Canada
7.1
Good
9,678 reviews
Delta
8.0
Very good
7,970 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Overall

8.0

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 $875, United Airlines will fly you from Porto to Seattle and back. In addition to United Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Air Canada and Lufthansa - these airlines can fly you to your destination from $876 and $886, respectively.

  • 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 ($686), Iberia ($751), and British Airways ($752).

  • 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 $390). 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
Lynnwood
Renton
Olympia
Shoreline
Puyallup
Cle Elum
Centralia
Kent
Federal Way
Chehalis
Kirkland
Aberdeen
Shelton

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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
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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 July 3, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$756Average$848FlexibilityNo cancel feeOn-time75%

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