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$379+ 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 3/19. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — OPO
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
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The best prices from Seattle/Tacoma Intl to Porto are usually found in January or November, booked 89 days in advance, depart on a Tuesday or Monday and return on a Monday

Cheap 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 February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$620
(Gotogate)

One-way from

$432
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$898
Provider with most accurate pricing for Seattle/Tacoma Intl-Porto flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Porto flights.
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From Seattle/Tacoma Intl to Porto
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One-way flight from Seattle/Tacoma Intl to Porto
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Highest demand for flights based on searches. 21% potential increase in price ($305 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease ($43 potential savings vs. average RT price).
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Average for round-trip flights in February 2025
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Find 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 February 20, 2025.

This Gotogate deal was found by Cheapflights users on 2/19. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/16:05 amSEA - OPO
2 stops21h 20mMultiple Airlines
Wed 4/96:15 amOPO - SEA
1 stop18h 44mMultiple Airlines
Deal found 2/19$615
This United Airlines deal was found by Cheapflights users on 2/19. 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.
Tue 4/112:20 pmSEA - OPO
1 stop13h 25mUnited Airlines
Tue 4/86:00 amOPO - SEA
1 stop14h 25mUnited Airlines
Deal found 2/19$622
This KLM deal was found by Cheapflights users on 2/18. 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.
Tue 3/42:10 pmSEA - OPO
1 stop36h 20mKLM
Wed 3/124:10 pmOPO - SEA
1 stop27h 30mKLM
Deal found 2/18$631
This Gotogate deal was found by Cheapflights users on 2/20. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/12:15 pmSEA - OPO
1 stop17h 30mLufthansa
Wed 4/96:15 amOPO - SEA
1 stop18h 44mLufthansa
Deal found 2/20$632
This Delta deal was found by Cheapflights users on 2/20. 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.
Mon 3/171:35 pmSEA - OPO
1 stop14h 15mDelta
Tue 4/111:25 amOPO - SEA
1 stop36h 35mDelta
Deal found 2/20$637
This SWISS deal was found by Cheapflights users on 2/19. 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.
Tue 4/112:45 pmSEA - OPO
2 stops38h 40mSWISS
Wed 4/98:40 amOPO - SEA
2 stops20h 35mSWISS
Deal found 2/19$651
This Gotogate deal was found by Cheapflights users on 2/19. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/181:25 pmSEA - OPO
2 stops21h 15mBritish Airways
Wed 4/28:15 amOPO - SEA
2 stops22h 52mBritish Airways
Deal found 2/19$668
This oojo deal was found by Cheapflights users on 2/19. 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.
Tue 4/227:10 pmSEA - OPO
1 stop36h 40mTurkish Airlines
Tue 5/204:50 pmOPO - SEA
1 stop32h 25mTurkish Airlines
Deal found 2/19$751
This Air Canada deal was found by Cheapflights users on 2/19. 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.
Sat 3/297:05 pmSEA - OPO
2 stops36h 35mAir Canada
Sun 4/136:15 amOPO - SEA
2 stops23h 48mAir Canada
Deal found 2/19$953

Find flights from Seattle to Porto within your budget

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 February 20, 2025.

Fly from

Seattle

Fly to

Porto

Route

Depart

Return

Price

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 4/1

6:05 am-11:25 am

2 stops21h 20m

Porto

Wed 4/9

6:15 am-4:59 pm

1 stop18h 44m

$615

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 4/1

12:20 pm-9:45 am

1 stop13h 25m

Porto

Tue 4/8

6:00 am-12:25 pm

1 stop14h 25m

$622

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 3/4

2:10 pm-10:30 am

1 stop36h 20m

Porto

Wed 3/12

4:10 pm-12:40 pm

1 stop27h 30m

$631

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 4/1

2:15 pm-3:45 pm

1 stop17h 30m

Porto

Wed 4/9

6:15 am-4:59 pm

1 stop18h 44m

$632

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 3/17

1:35 pm-10:50 am

1 stop14h 15m

Porto

Tue 4/1

11:25 am-4:00 pm

1 stop36h 35m

$637

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 4/1

12:45 pm-11:25 am

2 stops38h 40m

Porto

Wed 4/9

8:40 am-9:15 pm

2 stops20h 35m

$651

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 3/18

1:25 pm-5:40 pm

2 stops21h 15m

Porto

Wed 4/2

8:15 am-11:07 pm

2 stops22h 52m

$668

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 4/22

7:10 pm-3:50 pm

1 stop36h 40m

Porto

Tue 5/20

4:50 pm-5:15 pm

1 stop32h 25m

$751

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 3/29

7:05 pm-3:40 pm

2 stops36h 35m

Porto

Sun 4/13

6:15 am-10:03 pm

2 stops23h 48m

$953

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 3/19

6:20 am-9:15 am

3 stops43h 55m

$379

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/18

Showing 1-10 of 14 results
1
2

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 February.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*1 star

*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.

Travel insights for flights from Seattle to Porto

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

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 February 14, 2025.

Booking 89 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 $523). Flying from Seattle to Porto in June is currently the most expensive (average of $1,092). 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.

What is the cheapest time of day to fly from SEA to OPO?

Find hourly flight availability from Seattle to Porto. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 20, 2025.

It’s optimal to fly from Seattle to Porto in the evening. By choosing this option you can save up to 26% on the cost of your flight, compared to a flight in the morning.

What is the cheapest day to fly from Seattle to Porto?

Use this chart to determine the cheapest time to fly round-trip from Seattle to Porto. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Seattle to Porto flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in Porto by month

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

In terms of precipitation, rainfall in Porto ranges from 0.7 - 7.7 inches per month. December is typically the wettest month, when rainfall can reach 7.7 in. July is typically the driest time to visit Porto when rainfall is around 0.7 in.

Temperature in Porto by month

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

If weather is an important factor for your trip to Porto, 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 68.0 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 48.2 F).

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 February 20, 2025.
To help decide which airline to fly from Seattle to Porto, see what other customers have to say about Delta, KLM and United Airlines. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
8,219 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Comfort

8.0

Food

7.3

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Delta
8.0
Very good
8,219 reviews
Delta
8.0
Very good
8,219 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Comfort

8.0

Food

7.3

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

KLM
7.8
Good
1,333 reviews
Delta
8.0
Very good
8,219 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Comfort

8.0

Food

7.3

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

United Airlines
7.4
Good
8,765 reviews
Delta
8.0
Very good
8,219 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Comfort

8.0

Food

7.3

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Turkish Airlines
7.3
Good
3,832 reviews
Delta
8.0
Very good
8,219 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Comfort

8.0

Food

7.3

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
8,219 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Comfort

8.0

Food

7.3

Crew

8.5

Reviews

1 / 20

10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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.

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

    Our cheapest airline available from Seattle to Porto is United Airlines. Our recent data shows that you can find tickets from as low as $621 on this airline. Additional options worth looking into are Lufthansa and KLM, starting at $632 and $636 round-trip. Users have found that United Airlines is 44% cheaper than the other options available to this destination.

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

    $499 is the cheapest one-way deal found within the past few days, from KLM. You may also be able to find cheap deals on United Airlines and Delta, with prices starting from $510 and $685, 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 $523). Flying from Seattle to Porto in June is currently the most expensive (average of $1,092). 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?

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Matosinhos
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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 February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$649Average$1,130FlexibilityNo cancel feeOn-time75%
British AirwaysCheapest$673Average$877FlexibilityNo cancel feeOn-time70%
DeltaCheapest$674Average$1,187FlexibilityNo cancel feeOn-timeN/A
Turkish AirlinesCheapest$759Average$910FlexibilityNo cancel feeOn-time77%
LufthansaCheapest$769Average$1,169FlexibilityNo cancel feeOn-time76%
United AirlinesCheapest$851Average$1,293FlexibilityNo cancel feeOn-time69%
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