SEA - OPO

$298 Find Cheap Flights from Seattle to Porto

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to Porto departing on 8/16. 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, 0 bags

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

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Porto.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Porto.
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Everything you should know

Cheapest round-trip
$749
Typical prices: $1,067-$682
Scandinavian Airlines
Tue 11/3Thu 11/19
SEA - OPO • 2 stops
Cheapest one-way
$298
Typical prices: $441-$868
Multiple Airlines
Sun 8/16
SEA - OPO • 2 stops
Top airlines
Cheapest • from $749 (round-trip)
Best reviews • 7.9 score
Airline reviews
Airline reviews
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Airline reviews
Airline reviews
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Nonstop flights
Not available
There are currently no direct flights between Seattle and Porto. You'll need at least 1 connection.
Insights
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Insights
Top layover airports
Cheapest • Avg $794 (round-trip)
Shortest trip • 14h 17m (one-way)
Insights
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When to book
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 42% compared to booking last minute.
Insights
Insights
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Insights
When to travel
Cheapest • 44% price drop
Most popular
Good to know
Good to know
+1
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We hope you love your trip to Porto!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Seattle to Porto (SEA-OPO)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to Porto 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 Seattle to Porto

Tue, Nov 3 - Thu, Nov 19
Scandinavian Airlines Logo
7:20 am - 11:05 am
SEA
-
OPO
19h 45m
2 stops
Scandinavian Airlines Logo
5:50 pm - 12:18 am
OPO
-
SEA
38h 28m
2 stops
$749Scandinavian Airlines
Tue, Sep 8 - Tue, Sep 22
Multiple Airlines Logo
3:40 pm - 7:35 am
SEA
-
OPO
31h 55m
3 stops
Multiple Airlines Logo
7:10 am - 8:40 pm
OPO
-
SEA
21h 30m
2 stops
$757Multiple Airlines
Wed, Nov 4 - Wed, Nov 18
British Airways Logo
6:50 pm - 5:50 pm
SEA
-
OPO
15h 00m
1 stop
British Airways Logo
8:40 pm - 10:15 pm
OPO
-
SEA
33h 35m
2 stops
$771British Airways
Mon, Nov 2 - Mon, Nov 16
Iberia Logo
6:50 pm - 8:00 pm
SEA
-
OPO
17h 10m
2 stops
Iberia Logo
9:55 pm - 4:55 pm
OPO
-
SEA
27h 00m
2 stops
$773Iberia
Wed, Nov 4 - Wed, Nov 18
British Airways Logo
2:46 pm - 5:50 pm
SEA
-
OPO
19h 04m
2 stops
British Airways Logo
8:40 pm - 10:15 pm
OPO
-
SEA
33h 35m
2 stops
$776British Airways
Mon, Nov 9 - Mon, Nov 23
Multiple Airlines Logo
5:24 am - 8:00 pm
SEA
-
OPO
30h 36m
2 stops
Multiple Airlines Logo
8:40 pm - 10:15 pm
OPO
-
SEA
33h 35m
2 stops
$782Multiple Airlines
Sun, Nov 1 - Sat, Nov 21
Scandinavian Airlines Logo
7:20 am - 11:05 am
SEA
-
OPO
19h 45m
2 stops
Scandinavian Airlines Logo
12:00 pm - 10:12 pm
OPO
-
SEA
42h 12m
2 stops
$783Scandinavian Airlines
Wed, Nov 4 - Wed, Nov 18
British Airways Logo
6:50 pm - 5:50 pm
SEA
-
OPO
15h 00m
1 stop
British Airways Logo
6:35 pm - 11:30 am
OPO
-
SEA
24h 55m
1 stop
$787British Airways
Mon, Oct 26 - Thu, Nov 5
Multiple Airlines Logo
8:20 am - 8:00 pm
SEA
-
OPO
28h 40m
2 stops
Multiple Airlines Logo
8:40 pm - 9:18 pm
OPO
-
SEA
32h 38m
2 stops
$788Multiple Airlines
Sun, Aug 23 - Thu, Sep 3
Scandinavian Airlines Logo
3:55 pm - 10:00 pm
SEA
-
OPO
22h 05m
2 stops
Scandinavian Airlines Logo
11:50 am - 1:45 pm
OPO
-
SEA
33h 55m
1 stop
$793Scandinavian Airlines
Booking Insights

KAYAK's insights & trends for Seattle to Porto flights

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

How much is a round-trip flight from Seattle to Porto?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Seattle to Porto departing in November.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle to Porto, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Seattle to Porto is January, where tickets cost $498 (return) on average. On the other hand, the most expensive months are December and August, where the average cost of round-trip tickets is $1,451 and $1,057 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Seattle to Porto, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Seattle to Porto, you should book around 3 weeks before departure, which saves you about 42% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$298
Best time to beat the crowds with an average 45% drop in price.
Most popular time to fly with an average 1% increase in price.
Flight from Seattle to Porto

When to book flights from Seattle to Porto

Are your dates flexible? Find out the best times to travel from Seattle to Porto 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 Seattle to Porto

  • Do I need to get a visa before this flight?

    Traveling to Portugal for a stay in the Schengen area is hassle-free if your trip is for under 90 days within a 180-day timeframe. No visa is required for this duration. Keep in mind that a new 180-day period starts after spending 90 consecutive days outside the Schengen area. This allows you to enjoy your stay in Portugal without worrying about obtaining a visa.

  • What are some reasons to consider upgrading to First Class on Delta Air Lines?

    Enjoy the comfort of wider and more spacious seats and the added convenience of ticket flexibility without change fees. With Sky Priority service, your journey will be well-crafted from the beginning to the end. Indulge in a travel experience like no other, making your trip truly unforgettable in First Class.

  • What is a good choice for a sustainable airline on this trip?

    United Airlines is deeply dedicated to operating as an environmentally sustainable and responsible airline, with this commitment deeply embedded in its strategy and core principles. By the year 2050, the airline strives to achieve a remarkable goal of completely eliminating 100% of its greenhouse gas (GHG) emissions, going beyond the conventional reliance on carbon offsets. As part of its mid-term objective, United aims to reduce its carbon intensity by an impressive 50% by the year 2035, comparing against the levels recorded in 2019.

  • If I have special dietary needs, what is a good airline choice?

    On KLM, you have the convenience of ordering a customized meal that caters to your specific dietary needs. They offer various options, including low-fat, low-salt, meals suitable for diabetic, gluten-intolerance, or lactose-intolerance diets. Additionally, there is a limited number of vegetarian meals available on each flight. To ensure you receive your preferred vegetarian or vegan meal, it is advisable to place your order at least 24 h before your scheduled departure.

  • What is the cheapest flight from Seattle to Porto?

    In the last 7 days, the lowest price for a flight from Seattle to Porto was $298 for a one-way ticket and $749 for a round-trip.

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

    Yes, you’ll need a passport to travel to Porto from Seattle.

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

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

  • Which airline alliances offer flights from Seattle to Porto?

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

  • Which is the best airline for flights from Seattle to Porto, Delta or KLM?

    The two airlines most popular with KAYAK users for flights from Seattle to Porto are Delta and KLM. With an average price for the route of $1,001 and an overall rating of 7.9, Delta is the most popular choice. KLM is also a great choice for the route, with an average price of $953 and an overall rating of 7.8.

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

    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 Seattle to Porto.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Porto from Seattle 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 Seattle to Porto?

    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 Porto with an airline and back to Seattle with another airline. Booking your flights between Seattle and OPO 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 Seattle to Porto?

    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 Porto from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Seattle to Porto

  • If you would like a way to Seattle Tacoma International Airport (SEA) that does not involve driving yourself, check out the 1-Line from Sound Transit that riders can take from Pioneer Square Station to the airport in about 33 minutes.
  • Because there are no direct flights available on this trip, some layover airports you can expect to use include Amsterdam Airport Schiphol (AMS), San Francisco International Airport (SFO), and Zurich Airport (ZRH).
  • When you fly with WestJet, carry-in bags can be no bigger than 21 x 9 x 15 inches, and a personal item can be no larger than 16 x 16 x 13 inches. There is no weight limit for either bag.
  • Before checking bags on Air France flights, make sure bags don't exceed linear dimensions greater than 62.2 inches, including wheels, pockets, and handles. The weight allowance for Economy Classes is a maximum of 50 lb, while Business and La Premiere Classes allow up to 70 lb.
  • When flying with American Airlines, you are permitted to bring one golf bag containing golf clubs, golf balls, golf tees, and one pair of golf shoes. It's essential to be aware that standard checked bag fees, which vary depending on your destination, will apply to bags weighing up to 50 lb and measuring up to 126 inches in total dimensions.

Reviews of the top 5 airlines serving from Seattle to Porto

 
See real verified KAYAK customer reviews for airlines flying from Seattle to Porto. 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 Seattle to Porto? 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.
7.9
DeltaOverall score based on 8425 reviews
7.2Food
8.1Boarding
7.8Entertainment
8.5Crew
7.8Comfort
Airline reviews

Planes were clean, no water or snacks on either flight.

6.0 GoodAnonymous, May 2026
ECP - ATL
Read more Delta reviews

Planes were clean, no water or snacks on either flight.

Free & relatively fast Wi-Fi. Would've liked a wider drink selection.

I continue to be satisfied with Delta’s excellent service out of LGA. The digit id works well and gets me through security in no time. Whenever possible, I choose Delta.

Was revoked with Jet Blue due to delay from Kenya Air

The Boarding process was great. Particularly since my wife and I require assistance. The flight attendants were amazing. We travel frequently; they honestly were a cut above. 😀

Enjoyed it very much. Especially liked the free WiFi that Delta offers.

Smooth flight. Left on time, and got in 15 minutes early. Onboard video was great

For some reason, TSA Atlanta didn’t have my bag on the flight on time and they don’t have to provide Delta a reason for that.

WiFi didn’t work on two of four planes. Flight attendants were not overly friendly or welcoming. Planes were extremely slow to board and deplane.

Delta does a great job with entertainment and free wifi. I can still be in touch with my colleagues while in the air.

Brand new plane lots of room the snack was very flavourful and enjoyable

The flight was delayed. The aircraft was unclean. Promised seat was not given due to change in Aircraft. Not one crew on ground was in a position to give any response. Amsterdam Airport is AVIODABLE Over crowded. Over Expensive. Poor Services.

It was really nice journey i personally recommend klm flight

The crew were unprofessional with a racist element. I was physically abused as well from one of the crew members

Empty seats next to me - wish it had been for a longer flight!!

I’m grateful for the KLM Air France shuttle bus service to Ottawa. However due to construction and other issues related to the chaotic Uber pickup system at YUL, it’s a challenge to find the Kelios bus service to Ottawa. The signs are not clear or even available. No staff to guide passengers. It’s a stressful experience.

At the airport, terrible, I do not want to even remember it. It was too humiliating for a business class passenger.

Flight was ok but lack of communication cost me to literally beg to be put on another flight as connecting flight had departed

They forgot to serve food and the crew was very unfriendly. Never experienced such a bad KLM flight. Usually fly from Toronto. New York was different.

Couldn’t get boarding pass in SLC even with help from a redcoat, so had to find a desk in AMS to get boarding pass. Technical problems so not sure why. Very inconvenient. The KLM app is not as user friendly as most apps. Also had to wait almost an hour on the tarmac for a fuel truck, which caused us to miss a connecting bus in LUX.

Seat pitch is horrible especially on the 15 hour flight. Gate crew at SFO was Outstanding. The flight crew was also great.

Easy of boarding, helpfully staff at check in, surprisingly comfortable seating

Check in was chaotic with only one counter for business class and first class. The luggage conveyor belt at JFK airport was broken so the flight departure was delayed which made the flight stressful as I had a tight connection. Although the captain said they could make up the delay, they didn’t do so.

Had a one hour delay due to mechanical issue. I didn’t think I’d be able to make my connecting flight, but they waited for me and greeted me when I arrived to help things run smooth.

Lost of requested seat assignments. Lost my husband's meal choice

6 1/2 hours from Tampa to SFO on a Boeing 737. Cramped. No Service. No real food. One pass for coffee at the beginning and a second pass THREE hours later. And check-in in Tampa was nasty even by United standards. And I am at almost TWO million miles on United. It's a non-stop. But terrible service.

MY FAMILY'S LUGGAGE WAS LOST FROM ROME TO BARI. I WAS THE ONLY ONE THAT RECEIVED MY LUGGAGE FROM ROME TO BARI. AFTER DEPLANING IN BARI, WE WASTED A LOT OF TIME AT BAG CLAIMS LOST AND FOUND REPORTING THE CLAIM AND PLEADING FOR THE BAGS TO BE DELIVERED THE NEXT DAY. WE WERE TOLD THAT IT TAKES 3 DAYS MINIMUM TO DELIVER. MY DAUGHTER AND MY GIRLFRIEND NEEDED THEIR PERSONAL THINGS AND WE WERE STAYING 3 HOURS AWAY FROM THE BARI AIRPORT. WE HAD TO DRIVE 3 HOURS TO THE AIRPORT TO COLLECT OUR LOST LUGGAGE THE NEXT DAY. WE ARE NOT HAPPY WITH THE EXPERIENCE

We had a delay, but thankfully I made it to my connection. Overall it went smooth

The flight had a delay but I made it to my connection. Flight was smooth overall

As I wrote earlier, poor planning and/or communication. At least twice, we were told that we would be boarding in less than ten minutes, only to have the flight again delayed at least another hour.

Loved and was pleasantly surprised by the food!! Request Lufthansa to help transiting passengers at Munich (confusion whether to go thru passport control or not).

The flight was comfortable and the staff were helpful and friendly. However, we did not know we were flying PAL until we arrived in Canada, so it was a bit disconcerting. In addition, which port we were leaving from was confusing.

They did not let us board because one member needed a transit visa, which was not evident at the time of ticket purchase.

I was charge a baggage checking fee $68!! I volunteered to check my duffle bag which usually goes under my seat!

I did not like anything because the flight was cancelled yesterday and I did not get to arrive on time in Toronto as I was rebooked with another airline. This caused me to be really stressed out as I am an individual with back injury and to be forced to stay longer in an airport to accommodate a change of airline and the transfers associated with it Due to this I am probably not going to book through your website to eliminate this potentially chaos in the future

shittiest airline in the hemisphere. To improve - start thinking you're flying people, not cattle

Easy boarding, inflight refreshments came on time and comfortable seat

It was good that our flight left early. It was a nice smooth flight and landing.

All good……but luggage didn’t make it on the airplane. Had to wait 3 days. Was a bummer.

Small suitcase used for carryon the last time was refused by boarding crew this time. Appears to be at the discretion and mood of the person on the day. Flight was only half booked, there would have been no problem with space.

Extremely uncomfortable seats. Experience was like a Frontier Airlines flight. Would not fly it again.

Very, very tight legroom. They must’ve jammed in an additional few rows of seat seating. Denver to Munich was the least legroom I’ve ever had on any flight, let alone a multi hour international journey. I will not take that flight again.

In my first flight with Air Canada we sat in the plane for 4:00pm to 6:30pm. Finally we were asked to get off the plane and we were told the flight was cancelled after 7:00pm There was o clear explanation of what was the problem. I was booked without my permission on a Delta Flight at 7:30pm that was leaving at 8:00pm and I still had to go get my luggage(my final destination was Rome with one stop in Toronto. The luggage claim for Canada was closed so had to return to finally get it on the luggage belt.. Of course I missed the Delta flight and all the next day flights were booked. I also lost what I paid for my stay in Rome because I did nt cancel in time. A complete nightmare.

Good food, overall very comfy. The flight was full so obviously not optimal, but it is what it is.

Perfect airline, super friendly, great service, tasty food. Would fly again.

Parents with permanently crying baby on board. Neither parents nor crew did anything to calm the baby. The food was extremely disappointing. Seafood stew was very, very small! Not even appetizer size! Seat had a gap in the back. Had to use a pillow to fill it.

Food choices limited & not enticing Seats quite uncomfortable & difficult to control

Definitely get premium economy on a flight this long if you can. Your legs and while body will thank you.

Flight was delayed by several hours and then cancelled due to weather. But Staff was very helpful getting me on a different flight. United should offer food coupons and tooth brush and paste for stranded passengers

I upgraded to the business class cabin. It was the poorest business class I have ever experienced. No access to any business lounge in Tampa airport. Seats are not comfortable. I had a window seat and had to step/crawl over the next seat. Food was mediocre and service below average for business class. Bathroom location was ridiculous. No place to wait. I cannot believe I paid this kind of money and will never fly Lufthansa Discover again. They really should reimburse me somehow.

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

Information on your arrival and departure airports