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$271+ Cheap flights from Seattle (SEA) to Porto (OPO)

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 5/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — OPO
Apr 28 — May 51
Tue 4/28
Tue 5/5
1 adult, Economy
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Find cheap flights from Seattle to Porto with Cheapflights

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Cheap flight deals from Seattle to Porto

Cheapest flights from Seattle to Porto
Explore the most affordable flight options available from Seattle to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 29, 2026.

This oojo deal was found by Cheapflights users on 3/25. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/37:10 pm
SEA
-
OPO
1 stop36h 40m
Turkish Airlines
Tue 5/264:50 pm
OPO
-
SEA
1 stop32h 25m
Turkish Airlines
Deal found 3/25$681
This Turkish Airlines deal was found by Cheapflights users on 3/26. 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.
Thu 9/107:10 pm
SEA
-
OPO
1 stop36h 30m
Turkish Airlines
Tue 9/2210:40 am
OPO
-
SEA
1 stop38h 35m
Turkish Airlines
Deal found 3/26$707
This oojo deal was found by Cheapflights users on 3/28. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/97:10 pm
SEA
-
OPO
1 stop30h 30m
Turkish Airlines
Wed 9/304:40 pm
OPO
-
SEA
1 stop32h 35m
Turkish Airlines
Deal found 3/28$711
This Turkish Airlines deal was found by Cheapflights users on 3/27. 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.
Thu 4/237:10 pm
SEA
-
OPO
1 stop30h 35m
Turkish Airlines
Tue 4/2810:40 am
OPO
-
SEA
1 stop38h 35m
Turkish Airlines
Deal found 3/27$717
This oojo deal was found by Cheapflights users on 3/25. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/37:10 pm
SEA
-
OPO
1 stop36h 40m
Turkish Airlines
Mon 5/2510:40 am
OPO
-
SEA
1 stop38h 35m
Turkish Airlines
Deal found 3/25$720
This FlightHub deal was found by Cheapflights users on 3/25. 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.
Tue 5/57:10 pm
SEA
-
OPO
1 stop20h 20m
Turkish Airlines
Tue 5/124:50 pm
OPO
-
SEA
1 stop32h 25m
Turkish Airlines
Deal found 3/25$732
This Expedia deal was found by Cheapflights users on 3/24. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/173:10 pm
SEA
-
OPO
2 stops36h 35m
Iberia
Thu 10/298:20 am
OPO
-
SEA
2 stops22h 55m
Iberia
Deal found 3/24$737
This oojo deal was found by Cheapflights users on 3/25. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/237:10 pm
SEA
-
OPO
1 stop36h 30m
Turkish Airlines
Sun 4/2610:45 am
OPO
-
SEA
1 stop38h 30m
Turkish Airlines
Deal found 3/25$739
This Turkish Airlines deal was found by Cheapflights users on 3/27. 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.
Fri 4/247:10 pm
SEA
-
OPO
1 stop30h 35m
Turkish Airlines
Fri 5/110:40 am
OPO
-
SEA
1 stop38h 35m
Turkish Airlines
Deal found 3/27$747
This Turkish Airlines deal was found by Cheapflights users on 3/26. 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.
Mon 5/117:10 pm
SEA
-
OPO
1 stop30h 35m
Turkish Airlines
Mon 5/184:50 pm
OPO
-
SEA
1 stop32h 25m
Turkish Airlines
Deal found 3/26$748
This KAYAK deal was found by Cheapflights users on 3/28. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/307:00 pm
SEA
-
OPO
1 stop30h 55m
Turkish Airlines
Thu 1/2110:55 am
OPO
-
SEA
1 stop38h 10m
Turkish Airlines
Deal found 3/28$750

Find flight deals from Seattle to Porto

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Porto (OPO). 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 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$681
(oojo)

One-way from

$271
(Kiwi.com)

Popular in

December

Cheapest in

January

Average price

$680
Provider with most accurate pricing for Seattle/Tacoma Intl-Porto flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Porto flights.
Search Deals
From Seattle/Tacoma Intl to Porto
Search Deals
One-way flight from Seattle/Tacoma Intl to Porto
Search Deals
Highest demand for flights based on searches. 2% potential increase in price ($22 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($51 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Porto 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 29, 2026.
Use the filters below to find and compare flights from Seattle to Porto that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 4/24

7:10 pm-9:45 am

1 stop30h 35m

Porto

Fri 5/1

10:40 am-5:15 pm

1 stop38h 35m

$747
Quickest round-trip

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 4/14

2:10 pm-3:45 pm

1 stop17h 35m

Porto

Thu 4/23

6:00 am-8:53 pm

2 stops22h 53m

$830

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 5/5

7:20 am-10:55 am

2 stops19h 35m

Porto

Tue 5/12

5:00 am-6:48 pm

2 stops21h 48m

$889

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 4/22

7:15 am-10:40 am

2 stops19h 25m

Porto

Wed 5/6

5:00 am-7:03 pm

2 stops22h 03m

$894

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 4/17

7:10 pm-9:45 am

1 stop30h 35m

Porto

Tue 5/5

4:50 pm-5:15 pm

1 stop32h 25m

$915

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 4/24

6:40 pm-10:00 pm

1 stop19h 20m

Porto

Fri 5/1

9:25 am-11:51 pm

2 stops22h 26m

$920

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Thu 4/16

1:30 pm-3:25 pm

1 stop17h 55m

Porto

Mon 4/20

11:25 am-11:45 am

1 stop32h 20m

$992

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 4/17

11:10 am-3:25 pm

2 stops20h 15m

Porto

Tue 5/5

5:00 am-5:16 pm

2 stops20h 16m

$1,007

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 5/16

5:40 pm-10:15 pm

1 stop20h 35m

Porto

Sun 5/31

7:00 pm-4:24 pm

1 stop29h 24m

$1,114

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 5/13

1:21 pm-3:45 pm

2 stops42h 24m

Porto

Fri 5/29

4:45 pm-8:53 pm

2 stops36h 08m

$1,132

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/29

Showing 1-10 of 22 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Seattle to Porto

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 Seattle to Porto in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy2 starsTrust Score*2 stars
GurufarePrice Accuracy3 starsTrust Score*3 stars
OvagoPrice Accuracy2 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 Seattle-Porto flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Porto flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Porto flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-Porto 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 Seattle-Porto 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 Seattle to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from Seattle 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 Seattle to Porto

How far ahead should I book a flight from Seattle to Porto?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Porto. Price data was last updated on March 13, 2026.

Booking 45 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Porto. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, January is the cheapest month in which you can book a flight from Seattle to Porto (average of $478). Flying from Seattle to Porto in June is currently the most expensive (average of $749). 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.

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

Reviews of airlines servicing Porto

Get insights into the airlines that provide service to Porto. 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 Porto. Reviews last updated March 29, 2026.
Peruse reviews from past customers who have flown with Delta,KLM, andUnited Airlines from Seattle to Porto 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
7.9
Good
8,358 reviews

Entertainment

7.8

Boarding

8.1

Overall

7.9

Crew

8.5

Comfort

7.9

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Delta
7.9
Good
8,358 reviews
Delta
7.9
Good
8,358 reviews

Entertainment

7.8

Boarding

8.1

Overall

7.9

Crew

8.5

Comfort

7.9

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
KLM
7.8
Good
1,477 reviews
Delta
7.9
Good
8,358 reviews

Entertainment

7.8

Boarding

8.1

Overall

7.9

Crew

8.5

Comfort

7.9

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
United Airlines
7.4
Good
9,503 reviews
Delta
7.9
Good
8,358 reviews

Entertainment

7.8

Boarding

8.1

Overall

7.9

Crew

8.5

Comfort

7.9

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Air Canada
7.1
Good
10,854 reviews
Delta
7.9
Good
8,358 reviews

Entertainment

7.8

Boarding

8.1

Overall

7.9

Crew

8.5

Comfort

7.9

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Lufthansa
6.8
Okay
7,872 reviews
Delta
7.9
Good
8,358 reviews

Entertainment

7.8

Boarding

8.1

Overall

7.9

Crew

8.5

Comfort

7.9

Food

7.2

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Porto. 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 Seattle to Porto?

    A quick flight from Seattle to Porto can take about 17h 35m. Turkish Airlines provides one of the quickest options available for as low as $830. Airlines will cover a distance of 5083 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    Our cheapest airline available from Seattle to Porto is KLM. Our recent data shows that you can find tickets from as low as $490 on this airline. Additional options worth looking into are Lufthansa and Delta, starting at $503 and $582 round-trip. Users have found that KLM is 44% cheaper than the other options available to this destination.

  • What are the cheapest airlines to fly from Seattle to Porto one-way?

    $257 is the cheapest one-way deal found within the past few days, from United Airlines. You may also be able to find cheap deals on Scandinavian Airlines and Delta, with prices starting from $272 and $293, respectively.

  • Can I find deals for flights from Seattle to Porto that include hotel bookings?

    Yes. In addition to deals on Seattle to Porto flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Porto?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Porto.

  • Can I find deals for business class flights from Seattle to Porto?

    Yes. Cheapflights offers flight deals from Seattle to Porto 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 Seattle to Porto?

    Currently, January is the cheapest month in which you can book a flight from Seattle to Porto (average of $478). Flying from Seattle to Porto in June is currently the most expensive (average of $749). 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
Vila Nova de Gaia
Aveiro
Arcos de Valdevez
Coimbra

Browse thousands of different options on Cheapflights for your next trip

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Top 6 airlines flying from Seattle to Porto

Discover the top 6 airlines that operate flights from Seattle to Porto. 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 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$490Average$881FlexibilityNo cancel feeOn-time75%
LufthansaCheapest$503Average$855FlexibilityNo cancel feeOn-time76%
DeltaCheapest$582Average$908FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$654Average$974FlexibilityNo cancel feeOn-time69%
Air CanadaCheapest$660Average$823FlexibilityNo cancel feeOn-time67%
Air FranceCheapest$1,029Average$1,099FlexibilityNo cancel feeOn-time77%

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