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$329+ 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 9/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — OPO
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Porto are usually found in January or March, 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 June 12, 2025.

Round-trip from

$663
(FlightHub)

One-way from

$329
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$1,328
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. 17% potential increase in price ($220 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($27 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 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 June 12, 2025.

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.
Sat 10/187:15 pmSEA - OPO
2 stops39h 00mAir Canada
Sun 11/96:15 amOPO - SEA
2 stops40h 11mAir Canada
Deal found 6/11$655
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.
Tue 9/167:10 pmSEA - OPO
1 stop36h 40mTurkish Airlines
Tue 9/304:50 pmOPO - SEA
1 stop32h 25mTurkish Airlines
Deal found 6/11$663
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.
Sat 10/181:12 pmSEA - OPO
2 stops36h 33mUnited Airlines
Sun 11/912:40 pmOPO - SEA
1 stop31h 30mUnited Airlines
Deal found 6/10$670
This Gurufare 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 Gurufare is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/181:57 pmSEA - OPO
2 stops36h 23mLufthansa
Sun 11/96:15 amOPO - SEA
1 stop15h 05mLufthansa
Deal found 6/12$692
This Gotogate 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/167:15 pmSEA - OPO
2 stops30h 05mMultiple Airlines
Tue 9/306:00 amOPO - SEA
1 stop13h 55mMultiple Airlines
Deal found 6/12$712
This KAYAK 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/810:30 amSEA - OPO
2 stops25h 30mBritish Airways
Mon 12/298:40 pmOPO - SEA
2 stops28h 15mBritish Airways
Deal found 6/11$750
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.
Wed 10/81:45 pmSEA - OPO
2 stops20h 45mSWISS
Wed 10/297:20 pmOPO - SEA
2 stops34h 55mSWISS
Deal found 6/10$771
This KLM 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/191:30 pmSEA - OPO
1 stop18h 00mKLM
Mon 8/256:25 pmOPO - SEA
1 stop29h 30mKLM
Deal found 6/11$790
This Delta 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/51:30 pmSEA - OPO
1 stop18h 00mDelta
Fri 8/226:40 amOPO - SEA
2 stops23h 45mDelta
Deal found 6/10$800
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/81:55 pmSEA - OPO
2 stops18h 00mAmerican Airlines
Sat 8/238:15 amOPO - SEA
2 stops21h 18mAmerican Airlines
Deal found 6/11$895
This KAYAK 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/54:00 pmSEA - OPO
2 stops34h 40mScandinavian Airlines
Tue 9/166:15 amOPO - SEA
2 stops39h 45mScandinavian Airlines
Deal found 6/11$996

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 June 12, 2025.
Use the filters below to find and compare flights from Seattle to Porto that are best for you.

Fly from

Seattle

Fly to

Porto

Route

Depart

Return

Price

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 10/18

7:15 pm-6:15 pm

2 stops39h 00m

Porto

Sun 11/9

6:15 am-2:26 pm

2 stops40h 11m

$655

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 9/16

7:10 pm-10:05 am

1 stop30h 55m

Porto

Tue 9/30

10:50 am-5:15 pm

1 stop38h 25m

$663

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 10/18

1:12 pm-9:45 am

2 stops36h 33m

Porto

Sun 11/9

12:40 pm-12:10 pm

1 stop31h 30m

$670

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 10/18

1:57 pm-10:20 am

2 stops36h 23m

Porto

Sun 11/9

6:15 am-1:20 pm

1 stop15h 05m

$692

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 9/16

7:15 pm-9:20 am

2 stops30h 05m

Porto

Tue 9/30

6:00 am-11:55 am

1 stop13h 55m

$712

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 12/8

10:30 am-8:00 pm

2 stops25h 30m

Porto

Mon 12/29

8:40 pm-4:55 pm

2 stops28h 15m

$750

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 10/8

1:45 pm-6:30 pm

2 stops20h 45m

Porto

Wed 10/29

7:20 pm-11:15 pm

2 stops34h 55m

$771

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 8/19

1:30 pm-3:30 pm

1 stop18h 00m

Porto

Mon 8/25

6:25 pm-3:55 pm

1 stop29h 30m

$790

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 8/5

1:30 pm-3:30 pm

1 stop18h 00m

Porto

Fri 8/22

6:40 am-10:25 pm

2 stops23h 45m

$800

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 8/8

1:55 pm-3:55 pm

2 stops18h 00m

Porto

Sat 8/23

8:15 am-9:33 pm

2 stops21h 18m

$895

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

Showing 1-10 of 23 results
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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 June 9, 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 $1,047). 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 June 12, 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 June 12, 2025.
To help decide which airline to fly from Seattle to Porto, see what other customers have to say about Delta, KLM and SWISS. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,946 reviews

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

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

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

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

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

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

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

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

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

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

Entertainment

7.9

Overall

8.0

Boarding

8.2

Food

7.3

Crew

8.5

Comfort

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 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 Turkish Airlines. Our recent data shows that you can find tickets from as low as $663 on this airline. Additional options worth looking into are United Airlines and Lufthansa, starting at $729 and $733 round-trip. Users have found that Turkish Airlines is 35% cheaper than the other options available to this destination.

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

    $578 is the cheapest one-way deal found within the past few days, from Air Canada. You may also be able to find cheap deals on United Airlines and KLM, with prices starting from $583 and $597, 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 $1,047). 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?

Book flights to Seattle if you plan to visit one of these locations
Aveiro
Coimbra
Matosinhos
Arcos de Valdevez

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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 June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$636Average$1,078FlexibilityNo cancel feeOn-timeN/A
LufthansaCheapest$642Average$993FlexibilityNo cancel feeOn-time76%
KLMCheapest$648Average$1,017FlexibilityNo cancel feeOn-time75%
British AirwaysCheapest$673Average$1,134FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$679Average$1,204FlexibilityNo cancel feeOn-time69%
Turkish AirlinesCheapest$765Average$859FlexibilityNo cancel feeOn-time77%

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