OPO - SEA

$308 Find Cheap Flights from Porto to Seattle

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Porto to Seattle departing on 9/30. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to Seattle

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Porto to Seattle, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Porto to Seattle, as well as popular online travel agencies
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Flights Deals

Cheap Flights from Porto to Seattle (OPO-SEA)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Porto to Seattle that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Porto to Seattle

Tue, Sep 30 - Mon, Dec 22
Lufthansa Logo
6:00 am - 11:55 amOPO-SEA
13h 55m1 stop
Lufthansa Logo
2:00 pm - 2:55 pmSEA-OPO
16h 55m1 stop
$848Lufthansa
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Tue, Sep 30 - Mon, Dec 22
United Airlines Logo
6:00 am - 9:15 pmOPO-SEA
23h 15m2 stops
United Airlines Logo
2:00 pm - 2:55 pmSEA-OPO
16h 55m1 stop
$861United Airlines
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Tue, Sep 30 - Mon, Dec 22
United Airlines Logo
12:50 pm - 11:15 pmOPO-SEA
42h 25m3 stops
United Airlines Logo
2:00 pm - 2:55 pmSEA-OPO
16h 55m1 stop
$889United Airlines
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Tue, Sep 30 - Mon, Dec 22
United Airlines Logo
6:00 am - 10:30 pmOPO-SEA
24h 30m2 stops
United Airlines Logo
2:00 pm - 2:45 pmSEA-OPO
40h 45m3 stops
$947United Airlines
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Thu, Jul 31 - Thu, Aug 7
Logo
6:30 am - 3:50 pmOPO-SEA
17h 20m1 stop
Logo
1:30 pm - 6:15 pmSEA-OPO
20h 45m1 stop
$1,074
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Thu, Jul 31 - Thu, Aug 7
Delta Logo
6:30 am - 3:50 pmOPO-SEA
17h 20m1 stop
Delta Logo
6:10 am - 10:40 amSEA-OPO
20h 30m2 stops
$1,079Delta
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Thu, Jul 31 - Thu, Aug 7
Delta Logo
6:30 am - 8:55 pmOPO-SEA
22h 25m2 stops
Delta Logo
6:10 am - 10:40 amSEA-OPO
20h 30m2 stops
$1,189Delta
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Thu, Jul 31 - Thu, Aug 7
Logo
8:00 am - 4:25 pmOPO-SEA
40h 25m3 stops
Logo
3:45 pm - 10:35 amSEA-OPO
34h 50m3 stops
$1,193
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Fri, Aug 15 - Tue, Aug 26
Turkish Airlines Logo
4:50 pm - 10:35 amOPO-SEA
25h 45m1 stop
Turkish Airlines Logo
7:10 pm - 3:50 pmSEA-OPO
36h 40m1 stop
$3,174Turkish Airlines
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Fri, Aug 15 - Tue, Aug 26
SWISS Logo
8:40 am - 6:36 pmOPO-SEA
17h 56m2 stops
SWISS Logo
2:29 pm - 11:25 amSEA-OPO
36h 56m2 stops
$3,882SWISS
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KAYAK's insights & trends for Porto to Seattle flights

Get data-powered insights and trends into flights from Porto to Seattle to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Porto to Seattle?

The average price of all round-trip flights from Porto to Seattle clicked on KAYAK for each day over the last 12 months.

For Porto to Seattle, Monday is the cheapest day to fly on average and Saturday is the most expensive. Flying from Seattle back to Porto, the best deals are generally found on Tuesday, with Thursday being the most expensive.

Find deals

Good to know

Low seasonOctober
High seasonJuly
Cheapest flight$308
Best time to beat the crowds with an average 61% drop in price.
Most popular time to fly with an average 23% increase in price.
Flight from Porto to Seattle

When to book flights from Porto to Seattle

Are your dates flexible? Find out the best times to travel from Porto to Seattle based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Porto to Seattle

  • What is the cheapest flight from Porto to Seattle?

    In the last 3 days, the lowest price for a flight from Porto to Seattle was $308 for a one-way ticket and $848 for a round-trip.

  • Do I need a passport to fly between Porto and Seattle?

    A passport is required to fly from Porto to Seattle.

  • Which aircraft models fly most regularly from Porto to Seattle?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Porto to Seattle?

    Star Alliance, oneworld, and SkyTeam are the airline alliances operating flights between Porto and Seattle, with Star Alliance being the most commonly used for this route.

  • How does KAYAK find such low prices on flights from Porto to Seattle?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Porto to Seattle.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Porto to Seattle?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Seattle from Porto is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Porto to Seattle?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Seattle with an airline and back to Porto with another airline. Booking your flights between Porto and SEA can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Porto to Seattle?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Seattle from Porto up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airline flying from Porto to Seattle

 
See real verified KAYAK customer reviews for airlines flying from Porto to Seattle. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Porto to Seattle? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.8
KLMOverall score based on 1363 reviews
7.7Comfort
7.2Food
7.8Boarding
8.4Crew
7.1Entertainment
Airline reviews

I appreciate that KLM was proactive in informing me of the 2 hour delay which enabled me to replan my travel. It was a bit stressful not knowing whether my connection from Montreal to Ottawa was happening. But the ground and air crew did a good job at comforting and assuring me.

8.0 ExcellentShereen, Apr 2025AMS - YUL
Read more KLM reviews

I appreciate that KLM was proactive in informing me of the 2 hour delay which enabled me to replan my travel. It was a bit stressful not knowing whether my connection from Montreal to Ottawa was happening. But the ground and air crew did a good job at comforting and assuring me.

Cabin crew were excellent, very proffesional, polite and friendly, in flight snack was underwhelming, a packet of cheese biscuits, im sure KLM could run to a sandwich!

Legroom not all it could be, especially when the seat in front is reclined. Otherwise it was good, food and beverage were nice.

This portion of the flight was through Indigo. A local carrier. So all economy seating. No real service some refreshments for purchase standard economy stuff.

You should not have to pay for WiFi in business class

Transfer at Amsterdam airport is very convenient and the airport is easy to navigate. Boarding was also quick and easy. Cabin crew were excellent and the meals were good, although lacking in options.

This fight left ahead of time which meant it arrived early which was great. Staff were very professional, but as with all these Short hop Flights the food was a disappointing snack There was no entertainment on this flight, but I did not expect any

I flew premium economy and this was a good option. Although the seats didn’t recline much, I was able to get some sleep with my head propped against the window. The food was good and the entertainment was wonderful The staff were very attentive and professional

Great boarding, great short flight but no entertainment whatsoever and no wifi. Prepare to disembark by a staircase.

Great boarding, great short flight but no entertainment whatsoever. It was supposed to have wifi but that did not work.

Everything you need to know for your flight from Porto to Seattle

Information on your arrival and departure airports

Porto (OPO)
Seattle (SEA)

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