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Cheap flights from Seattle to Porto from $309

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Porto departing on 10/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Seattle to Porto

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
11:00 pm - 6:55 am
SEA
-
OPO
23h 55m
1 stop
United Airlines Logo
12:15 pm - 11:32 am
OPO
-
SEA
31h 17m
2 stops
$835United Airlines
Sat, Aug 8 - Tue, Aug 25
Air Canada Logo
7:20 pm - 7:00 am
SEA
-
OPO
51h 40m
2 stops
Air Canada Logo
12:15 pm - 10:48 pm
OPO
-
SEA
18h 33m
2 stops
$847Air Canada
Sat, Aug 8 - Tue, Aug 25
Multiple Airlines Logo
3:40 pm - 9:55 am
SEA
-
OPO
34h 15m
3 stops
Multiple Airlines Logo
10:30 pm - 9:40 am
OPO
-
SEA
43h 10m
3 stops
$854Multiple Airlines
Tue, Jun 2 - Fri, Jun 19
Lufthansa Logo
7:20 pm - 7:00 am
SEA
-
OPO
27h 40m
2 stops
Lufthansa Logo
6:20 am - 4:59 pm
OPO
-
SEA
18h 39m
1 stop
$895Lufthansa
Tue, Jul 21 - Wed, Jul 29
Multiple Airlines Logo
5:45 am - 7:00 am
SEA
-
OPO
17h 15m
2 stops
Multiple Airlines Logo
6:20 am - 4:59 pm
OPO
-
SEA
18h 39m
1 stop
$896Multiple Airlines
Sat, Aug 8 - Tue, Aug 25
Multiple Airlines Logo
5:45 am - 7:00 am
SEA
-
OPO
17h 15m
2 stops
Multiple Airlines Logo
6:20 am - 4:59 pm
OPO
-
SEA
18h 39m
1 stop
$897Multiple Airlines
Sat, Aug 8 - Tue, Aug 25
Multiple Airlines Logo
5:45 am - 7:00 am
SEA
-
OPO
17h 15m
2 stops
Multiple Airlines Logo
6:20 am - 4:59 pm
OPO
-
SEA
18h 39m
1 stop
$901Multiple Airlines
Wed, Jul 15 - Tue, Jul 28
Multiple Airlines Logo
5:45 am - 7:00 am
SEA
-
OPO
17h 15m
2 stops
Multiple Airlines Logo
6:20 am - 4:59 pm
OPO
-
SEA
18h 39m
1 stop
$902Multiple Airlines
Wed, Jul 15 - Tue, Jul 28
United Airlines Logo
5:00 am - 7:00 am
SEA
-
OPO
18h 00m
2 stops
United Airlines Logo
11:50 am - 9:10 pm
OPO
-
SEA
41h 20m
2 stops
$903United Airlines
Wed, Jul 22 - Thu, Jul 30
Lufthansa Logo
6:50 pm - 11:25 pm
SEA
-
OPO
20h 35m
1 stop
Lufthansa Logo
6:20 am - 4:59 pm
OPO
-
SEA
18h 39m
1 stop
$905Lufthansa
Wed, Jul 15 - Tue, Jul 28

SWISS flights from Seattle to Porto

Our best SWISS deals on Seattle to Porto flight tickets
SWISS
Nov 11
SEA11:00 amSeattle/Tacoma Intl
23h 30m
2 stops
OPO6:30 pmPorto
Nov 25
OPO7:20 pmPorto
36h 01m
2 stops
SEA11:21 pmSeattle/Tacoma Intl
$824
SWISS
Nov 11
SEA3:30 pmSeattle/Tacoma Intl
19h 00m
2 stops
OPO6:30 pmPorto
Nov 23
OPO7:20 pmPorto
36h 01m
2 stops
SEA11:21 pmSeattle/Tacoma Intl
$828

American Airlines flights from Seattle to Porto

Our best American Airlines deals on Seattle to Porto flight tickets
American Airlines
Oct 13
SEA12:57 pmSeattle/Tacoma Intl
19h 03m
2 stops
OPO4:00 pmPorto
Oct 21
OPO8:20 amPorto
19h 10m
2 stops
SEA7:30 pmSeattle/Tacoma Intl
$783
American Airlines
Oct 5
SEA12:57 pmSeattle/Tacoma Intl
19h 03m
2 stops
OPO4:00 pmPorto
Oct 14
OPO8:20 amPorto
19h 10m
2 stops
SEA7:30 pmSeattle/Tacoma Intl
$800

momondo 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, momondo users made 832,500 searches. Data last updated May 20, 2026.
Use the filters below to find and compare flights from Seattle to Porto that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 8/8

11:00 pm-6:55 am

1 stop23h 55m

Porto

Tue 8/25

12:15 pm-11:32 am

2 stops31h 17m

$835

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 8/8

7:20 pm-7:00 am

2 stops51h 40m

Porto

Tue 8/25

12:15 pm-10:48 pm

2 stops18h 33m

$847

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 6/2

3:40 pm-9:55 am

3 stops34h 15m

Porto

Fri 6/19

10:30 pm-9:40 am

3 stops43h 10m

$854

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 7/21

7:20 pm-7:00 am

2 stops27h 40m

Porto

Wed 7/29

6:20 am-4:59 pm

1 stop18h 39m

$895
Quickest round-trip

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 8/8

5:45 am-7:00 am

2 stops17h 15m

Porto

Tue 8/25

6:20 am-4:59 pm

1 stop18h 39m

$896

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 8/8

5:45 am-7:00 am

2 stops17h 15m

Porto

Tue 8/25

6:20 am-4:59 pm

1 stop18h 39m

$897

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 7/15

5:45 am-7:00 am

2 stops17h 15m

Porto

Tue 7/28

6:20 am-4:59 pm

1 stop18h 39m

$901

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 7/15

5:45 am-7:00 am

2 stops17h 15m

Porto

Tue 7/28

6:20 am-4:59 pm

1 stop18h 39m

$902

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 7/22

5:00 am-7:00 am

2 stops18h 00m

Porto

Thu 7/30

11:50 am-9:10 pm

2 stops41h 20m

$903

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 7/15

6:50 pm-11:25 pm

1 stop20h 35m

Porto

Tue 7/28

6:20 am-4:59 pm

1 stop18h 39m

$905

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Porto from

How to get the cheapest flight ticket from Seattle to Porto

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Seattle and Porto?

What is the cheapest month to fly to Porto?

The month of January is, on average, the cheapest month to fly to Porto from Seattle, with most prices found around $498. If you aren’t able to travel during the month of January, then book flights to Porto from Seattle during March instead. Flights to Porto in March, while not as cheap as those in January, still average around $680.

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

You are more likely to see cheaper flights to Porto from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Porto for around $895 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Porto from Seattle for as low as $710 on momondo.

Can stopping save me money on Seattle to Porto flights?

You could potentially save up to 28% on your flight if you consider stops on a Seattle to Porto flight.

How have Seattle to Porto flight prices changed over time?

When to book flights from Seattle to Porto

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to Porto according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to Porto (SEA to OPO) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to Porto

Fastest flight time

14h 00m

Direct flights

None
The fastest flight from Seattle to Porto takes 14h 00m
There are no direct flights from Seattle to Porto. There are no popular flight routes from Seattle to Porto.
Search flight deals

Frequently asked questions about flying from Seattle to Porto

  • How far is Seattle/Tacoma Intl to Porto by plane?

    Seattle/Tacoma Intl and Porto are 5083.1 mi apart from one another. Typically, this will take 14h 00m by plane in normal conditions.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Porto Airport?

    Prices for flights from Seattle/Tacoma Intl Airport to Porto Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Porto Airport?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Porto Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Porto Airport.

  • What documentation or ID do you need to fly to Porto Airport?

    The travel and health documents you'll need for your trip to Porto Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Porto Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Seattle to Porto?

Best airlines flying from Seattle to Porto

Compare and see reviews for airlines that fly from Seattle to Porto with momondo
Airline
Rating
Free Cancellation
Price
KLMPriceFrom $490Free CancellationRating
7.8
1,518 reviews
Search KLM flights
LufthansaPriceFrom $503Free CancellationRating
6.8
8,015 reviews
Search Lufthansa flights
DeltaPriceFrom $582Free CancellationRating
7.9
8,455 reviews
Search Delta flights
Air CanadaPriceFrom $660Free CancellationRating
7.1
11,065 reviews
Search Air Canada flights
Turkish AirlinesPriceFrom $665Free CancellationRating
7.4
4,382 reviews
Search Turkish Airlines flights
United AirlinesPriceFrom $691Free CancellationRating
7.4
9,739 reviews
Search United Airlines flights
Air FrancePriceFrom $1,029Free CancellationRating
7.4
1,588 reviews
Search Air France flights

Traveling to a place near Porto?

Book flights to Porto if you plan to visit one of these locations
Vila Nova de Gaia
Coimbra
Braga
Aveiro
Matosinhos
Lamego
Chaves
Esposende
Pinhao
Espinho
Guimarães
Arcos de Valdevez
Viseu
Ponte de Lima
Curia
Mesao Frio
Mira
Baiao

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to Porto?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Porto from Seattle.

Can I find flights from Seattle to Porto with flexible booking policies on momondo?

Yes. All flights to Porto from Seattle on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Seattle to Porto?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to Porto.

I’m not ready to book a flight from Seattle to Porto right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Porto, momondo offers a useful price alert feature which will track prices for flights to Porto from Seattle and alert you when they change.

An easier way to manage your Porto trip

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