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Cheap flights from Seattle to Porto from $263

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 4/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
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.
Delta Logo
1:40 pm - 10:30 am
SEA
-
OPO
12h 50m1 stop
Delta Logo
11:15 am - 11:35 am
OPO
-
SEA
32h 20m1 stop
$478Delta
Tue, Feb 3 - Sat, Mar 7
Multiple Airlines Logo
2:10 pm - 10:25 am
SEA
-
OPO
36h 15m1 stop
Multiple Airlines Logo
9:55 am - 11:50 am
OPO
-
SEA
33h 55m1 stop
$480Multiple Airlines
Wed, Jan 21 - Tue, Jan 27
Delta Logo
9:59 pm - 10:25 am
SEA
-
OPO
28h 26m2 stops
Delta Logo
5:00 am - 11:50 am
OPO
-
SEA
14h 50m1 stop
$482Delta
Wed, Jan 21 - Thu, Jan 29
Delta Logo
7:10 am - 10:30 am
SEA
-
OPO
19h 20m2 stops
Delta Logo
11:15 am - 11:35 am
OPO
-
SEA
32h 20m1 stop
$483Delta
Tue, Feb 3 - Thu, Mar 5
Delta Logo
3:10 pm - 3:25 pm
SEA
-
OPO
16h 15m1 stop
Delta Logo
5:00 am - 11:50 am
OPO
-
SEA
14h 50m1 stop
$484Delta
Tue, Jan 20 - Thu, Jan 29
Lufthansa Logo
7:00 am - 12:50 pm
SEA
-
OPO
21h 50m2 stops
Lufthansa Logo
6:30 am - 1:20 pm
OPO
-
SEA
14h 50m1 stop
$486Lufthansa
Fri, Feb 6 - Fri, Mar 6
Delta Logo
1:40 pm - 10:30 am
SEA
-
OPO
12h 50m1 stop
Delta Logo
11:15 am - 8:48 pm
OPO
-
SEA
40h 33m2 stops
$488Delta
Tue, Feb 3 - Mon, Mar 9
Delta Logo
6:05 am - 3:25 pm
SEA
-
OPO
25h 20m2 stops
Delta Logo
5:00 am - 11:50 am
OPO
-
SEA
14h 50m1 stop
$489Delta
Mon, Jan 19 - Thu, Jan 29
Delta Logo
2:10 pm - 10:25 am
SEA
-
OPO
36h 15m1 stop
Delta Logo
5:00 am - 6:58 pm
OPO
-
SEA
21h 58m2 stops
$490Delta
Wed, Jan 21 - Fri, Jan 30
Air Canada Logo
8:10 am - 1:15 pm
SEA
-
OPO
21h 05m2 stops
Air Canada Logo
6:00 am - 10:16 pm
OPO
-
SEA
24h 16m2 stops
$492Air Canada
Wed, Jan 21 - Sun, Jan 25

United Airlines flights from Seattle to Porto

Our best United Airlines deals on Seattle to Porto flight tickets
United Airlines
Feb 8
SEA7:00 amSeattle/Tacoma Intl
24h 15m
2 stops
OPO3:15 pmPorto
Mar 3
OPO12:30 pmPorto
37h 56m
2 stops
SEA6:26 pmSeattle/Tacoma Intl
$506
Find similar
United Airlines
Feb 4
SEA8:20 amSeattle/Tacoma Intl
46h 25m
3 stops
OPO2:45 pmPorto
Feb 11
OPO6:00 amPorto
24h 59m
2 stops
SEA10:59 pmSeattle/Tacoma Intl
$516
Find similar
United Airlines
Feb 4
SEA8:10 amSeattle/Tacoma Intl
23h 15m
2 stops
OPO3:25 pmPorto
Feb 8
OPO12:30 pmPorto
42h 13m
3 stops
SEA10:43 pmSeattle/Tacoma Intl
$529
Find similar

Delta flights from Seattle to Porto

Our best Delta deals on Seattle to Porto flight tickets
Delta
Feb 3
SEA1:40 pmSeattle/Tacoma Intl
12h 50m
1 stop
OPO10:30 amPorto
Mar 7
OPO11:15 amPorto
32h 20m
1 stop
SEA11:35 amSeattle/Tacoma Intl
$478
Find similar
Delta
Jan 21
SEA9:59 pmSeattle/Tacoma Intl
28h 26m
2 stops
OPO10:25 amPorto
Jan 29
OPO5:00 amPorto
14h 50m
1 stop
SEA11:50 amSeattle/Tacoma Intl
$482
Find similar
Delta
Feb 3
SEA7:10 amSeattle/Tacoma Intl
19h 20m
2 stops
OPO10:30 amPorto
Mar 5
OPO11:15 amPorto
32h 20m
1 stop
SEA11:35 amSeattle/Tacoma Intl
$483
Find similar

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 December 23, 2025.
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

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 2/3

1:40 pm-10:30 am

1 stop12h 50m

Porto

Sat 3/7

11:15 am-11:35 am

1 stop32h 20m

$478

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 1/21

2:10 pm-10:25 am

1 stop36h 15m

Porto

Tue 1/27

9:55 am-11:50 am

1 stop33h 55m

$480

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 1/21

9:59 pm-10:25 am

2 stops28h 26m

Porto

Thu 1/29

5:00 am-11:50 am

1 stop14h 50m

$482

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 2/3

7:10 am-10:30 am

2 stops19h 20m

Porto

Thu 3/5

11:15 am-11:35 am

1 stop32h 20m

$483

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 1/20

3:10 pm-3:25 pm

1 stop16h 15m

Porto

Thu 1/29

5:00 am-11:50 am

1 stop14h 50m

$484

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 2/6

7:00 am-12:50 pm

2 stops21h 50m

Porto

Fri 3/6

6:30 am-1:20 pm

1 stop14h 50m

$486

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 2/3

1:40 pm-10:30 am

1 stop12h 50m

Porto

Mon 3/9

11:15 am-8:48 pm

2 stops40h 33m

$488

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 1/19

6:05 am-3:25 pm

2 stops25h 20m

Porto

Thu 1/29

5:00 am-11:50 am

1 stop14h 50m

$489

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 1/21

2:10 pm-10:25 am

1 stop36h 15m

Porto

Fri 1/30

5:00 am-6:58 pm

2 stops21h 58m

$490

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 1/21

8:10 am-1:15 pm

2 stops21h 05m

Porto

Sun 1/25

6:00 am-10:16 pm

2 stops24h 16m

$492

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 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 $645. If you aren’t able to travel during the month of January, then book flights to Porto from Seattle during October instead. Flights to Porto in October, while not as cheap as those in January, still average around $730.

What is the cheapest day to depart on your flight to Porto?

The cheapest day to depart on your flight to Porto is on a Tuesday when prices can be found for as low as $1,008. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Thursday because tickets tend to average around $1,286. These prices are subject to change though, so be sure to set up a Price Alert for flights to Porto.

What is the cheapest time of day to depart on your flight to Porto?

In the evening is the cheapest time of day to fly from Seattle to Porto when you can find flight prices for as low as $837. Flying to Porto in the evening is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $1,130 on average. Flights to Porto from Seattle in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.

How far in advance should I book a flight 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 $994 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 $739 on momondo.

Can stopping save me money on Seattle to Porto flights?

You could potentially save up to 21% on your flight if you consider stops on a Seattle to Porto flight.

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

12h 50m

Direct flights

None
The fastest flight from Seattle to Porto takes 12h 50m
There are no direct flights from Seattle to Porto. There are no popular flight routes from Seattle to Porto.
Search flight deals

  • 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 12h 50m 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
LufthansaPriceFrom $619Free CancellationRating
6.8
7,650 reviews
Search Lufthansa flights
DeltaPriceFrom $636Free CancellationRating
7.9
8,015 reviews
Search Delta flights
KLMPriceFrom $659Free CancellationRating
7.7
1,434 reviews
Search KLM flights
Turkish AirlinesPriceFrom $665Free CancellationRating
7.3
4,112 reviews
Search Turkish Airlines flights
United AirlinesPriceFrom $679Free CancellationRating
7.4
9,109 reviews
Search United Airlines 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
Guimarães
Esposende
Lamego
Chaves
Viseu
Espinho
Arcos de Valdevez
Pinhao
Ponte de Lima
Curia
Penafiel
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

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
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