SEA - OPO

$285 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 11/14. 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
$738
Typical prices: $1,231-$862
Scandinavian Airlines
Sat 8/22Thu 9/10
SEA - OPO • 1 stop
Cheapest one-way
$285
Multiple Airlines
Sat 11/14
SEA - OPO • 2 stops
Top airlines
Cheapest • from $738 (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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Good to know
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KAYAK searches 100s of sites at once to find you the best travel deals.
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

Sat, Aug 22 - Thu, Sep 10
Scandinavian Airlines Logo
3:55 pm - 5:05 pm
SEA
-
OPO
17h 10m
1 stop
Scandinavian Airlines Logo
11:50 am - 1:45 pm
OPO
-
SEA
33h 55m
1 stop
$738Scandinavian Airlines
Tue, Aug 18 - Mon, Aug 24
Multiple Airlines Logo
3:40 pm - 5:50 pm
SEA
-
OPO
18h 10m
2 stops
Multiple Airlines Logo
6:00 pm - 9:40 am
OPO
-
SEA
47h 40m
3 stops
$740Multiple Airlines
Tue, Aug 18 - Mon, Aug 24
Multiple Airlines Logo
7:00 pm - 8:00 am
SEA
-
OPO
29h 00m
3 stops
Multiple Airlines Logo
6:00 pm - 9:40 am
OPO
-
SEA
47h 40m
3 stops
$751Multiple Airlines
Sat, Sep 26 - Fri, Oct 9
Scandinavian Airlines Logo
3:55 pm - 5:05 pm
SEA
-
OPO
17h 10m
1 stop
Scandinavian Airlines Logo
5:55 pm - 1:45 pm
OPO
-
SEA
27h 50m
1 stop
$757Scandinavian Airlines
Mon, Nov 9 - Mon, Nov 23
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
$774Iberia
Sat, Sep 5 - Sat, Sep 12
Multiple Airlines Logo
8:00 am - 12:40 am
SEA
-
OPO
32h 40m
3 stops
Multiple Airlines Logo
7:10 pm - 6:32 pm
OPO
-
SEA
31h 22m
3 stops
$775Multiple Airlines
Mon, Oct 19 - Wed, Oct 28
Iberia Logo
7:40 am - 4:00 pm
SEA
-
OPO
24h 20m
2 stops
Iberia Logo
8:40 pm - 11:08 am
OPO
-
SEA
21h 28m
2 stops
$781Iberia
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 - 11:05 pm
OPO
-
SEA
34h 25m
2 stops
$782Multiple Airlines
Sat, Nov 7 - Wed, Nov 25
Scandinavian Airlines Logo
7:20 am - 4:45 pm
SEA
-
OPO
25h 25m
2 stops
Scandinavian Airlines Logo
11:55 am - 10:11 pm
OPO
-
SEA
42h 16m
2 stops
$783Scandinavian Airlines
Tue, Aug 25 - Thu, Sep 10
Scandinavian Airlines Logo
3:55 pm - 11:00 am
SEA
-
OPO
35h 05m
1 stop
Scandinavian Airlines Logo
11:50 am - 1:45 pm
OPO
-
SEA
33h 55m
1 stop
$788Scandinavian 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 August.

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$285
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 $285 for a one-way ticket and $738 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 $1,004 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 8397 reviews
8.5Crew
7.2Food
7.8Comfort
7.8Entertainment
8.1Boarding
Airline reviews

Left /arrived on time. Decent seat space. Like the wifi/plugs and entertainment. Windows and tray table were kinda gross. Attendants didn't start snack service til 40mins before landing. Two rows before us, captain came on to say there's turbulence and recalled staff to seats. So, no drink/snack. Later, attendants didn't stop to see if we had trash nor even look our way. Felt invisible! Almost all pilot announcements were not only unintelligible, but so quiet. We had no idea what she said.

8.0 ExcellentAnonymous, Jun 2026
TPA - LGA
Read more Delta reviews

Left /arrived on time. Decent seat space. Like the wifi/plugs and entertainment. Windows and tray table were kinda gross. Attendants didn't start snack service til 40mins before landing. Two rows before us, captain came on to say there's turbulence and recalled staff to seats. So, no drink/snack. Later, attendants didn't stop to see if we had trash nor even look our way. Felt invisible! Almost all pilot announcements were not only unintelligible, but so quiet. We had no idea what she said.

Average seat comfort, a drink and chips were provided, early boarding because we checked a carryon at the gate was nice. Ticket pricing shenanigans, including fees to pick a seat, check a bag, and get food onboard - evidence the industry is reinvigorating last century’s strategies- destroys the experience before one ever arrives at the airport. It’s difficult to recognize any value or sustain loyalty in the end-to-end process making air travel more drudgery than pleasure.

Gate agent was unhelpful for handicapped boarding. Flight attendant seemed untrained.

No service flight that took 5 hrs and a stop at an unscheduled airport. Crew and pilots did their jobs

Clean planes and not take my comfort class seat away.

The crew were efficient. The pilots seemed professional. It was a bit chilly in our seats. The sheet provided weren’t very helpful.

Weather caused a long delay, but the efficiency and updates from the pilot were helpful. We were able to make our connection fortunately.

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.

As always, it’s a pleasure to travel with KLM. It is one of my favorite airlines.

Outstanding even though the 330 was one of the oldest in the fleet. The difference was the attentiveness and responsiveness of a really experienced flight attendant. For airline food great variety of interesting choices and good tastes supported by a good wine selection.

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

As per usual when you Hit the UK it's a slow process through customs Not as efficient at Thailand for sure

There were no charge points for phones on the economy seats. The seats were comfortable overall. Food was okay.. flight was on time

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.

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.

I flew from Santa Fe to Denver to catch a flight to London and the transfer of my luggage on arrival at Denver to the London flight worked perfectly. The crew on the ground and on board for the London flight were so friendly and efficient.

Boarded early; and arrived home 40 mins early. After a long flight, it’s nice to be back home early. These flights have no amenities; no snacks. So need to bring your own

Boarded early, left early, arrived 40 mins early! A win win for me!

New plane was lovely. Crew customer service is always lax but expected. Kraft on time and arrived safely.

These airplanes should be illegal. The seats are two tight, it is a safety issue. Wheelchair support was ridiculously slow. We almost missed our flight.

It was a short flight so I was expecting too much

Horrifying Almost 2 million miles. Bring your own food and drink. One coffee or drink every three hours. Have to order meals on app more than 24 hours ahead Tiny and dirty bathrooms

Flight was delayed but more than 90 minutes. This caused me to miss my available windows for pick-up by a friend. I had to pay $125 for an uber back home from the airport which was an added expense that I had not budgeted for my trip. Staff was friendly.

I felt scammed. The priced advertised was different than what I paid. I paid the whole some online. I then got a call 20 minutes later saying I need to paid 70 more person. She said the price online is not the guaranteed price.

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

Selected seats 5 months prior to date. Had email confirmation and seats were not honoured. Family did not sit together

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.

Put me on standby; flight was late; missed my connecting flight; disaster

Flight attendants were fine, seats a bit hard but I use a cushion for extra support. The only issue was it was a bit too cool and I needed to ask for and received and extra blanket. I survived!!!

Very few things and/or people are excellent. It was very good.

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

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

Information on your arrival and departure airports