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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 5/21. 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.
Multiple Airlines Logo
6:40 pm - 10:00 pm
SEA
-
OPO
19h 20m
1 stop
Multiple Airlines Logo
7:10 pm - 11:45 am
OPO
-
SEA
24h 35m
1 stop
$479Multiple Airlines
Mon, Apr 20 - Wed, Apr 29
Delta Logo
6:40 pm - 10:00 pm
SEA
-
OPO
19h 20m
1 stop
Delta Logo
5:00 am - 8:25 pm
OPO
-
SEA
23h 25m
2 stops
$489Delta
Mon, Apr 20 - Wed, Apr 29
Delta Logo
1:45 pm - 10:00 pm
SEA
-
OPO
24h 15m
2 stops
Delta Logo
5:00 am - 5:16 pm
OPO
-
SEA
20h 16m
2 stops
$494Delta
Mon, Apr 20 - Wed, Apr 29
Delta Logo
1:45 pm - 6:10 pm
SEA
-
OPO
20h 25m
1 stop
Delta Logo
5:00 am - 5:16 pm
OPO
-
SEA
20h 16m
2 stops
$495Delta
Sun, Apr 19 - Wed, Apr 29
Delta Logo
6:00 am - 6:10 pm
SEA
-
OPO
28h 10m
2 stops
Delta Logo
5:00 am - 6:26 pm
OPO
-
SEA
21h 26m
2 stops
$499Delta
Sun, Apr 19 - Wed, Apr 29
United Airlines Logo
10:35 pm - 9:45 am
SEA
-
OPO
27h 10m
2 stops
United Airlines Logo
12:35 pm - 11:37 am
OPO
-
SEA
31h 02m
2 stops
$501United Airlines
Mon, Apr 20 - Wed, Apr 29
Delta Logo
6:40 pm - 10:00 pm
SEA
-
OPO
19h 20m
1 stop
Delta Logo
5:00 am - 11:42 am
OPO
-
SEA
14h 42m
1 stop
$529Delta
Mon, Apr 20 - Sat, May 2
Delta Logo
6:40 pm - 10:00 pm
SEA
-
OPO
19h 20m
1 stop
Delta Logo
11:25 am - 11:42 am
OPO
-
SEA
32h 17m
1 stop
$532Delta
Mon, Apr 20 - Thu, Apr 30
Delta Logo
1:45 pm - 10:00 pm
SEA
-
OPO
24h 15m
2 stops
Delta Logo
5:00 am - 11:42 am
OPO
-
SEA
14h 42m
1 stop
$533Delta
Mon, Apr 20 - Sat, May 2
Delta Logo
5:35 pm - 6:10 pm
SEA
-
OPO
16h 35m
1 stop
Delta Logo
5:00 am - 11:42 am
OPO
-
SEA
14h 42m
1 stop
$534Delta
Sun, Apr 19 - Sat, May 2

United Airlines flights from Seattle to Porto

Our best United Airlines deals on Seattle to Porto flight tickets
United Airlines
Apr 20
SEA10:35 pmSeattle/Tacoma Intl
27h 10m
2 stops
OPO9:45 amPorto
Apr 29
OPO12:35 pmPorto
31h 02m
2 stops
SEA11:37 amSeattle/Tacoma Intl
$501
United Airlines
Aug 12
SEA7:30 amSeattle/Tacoma Intl
15h 25m
1 stop
OPO6:55 amPorto
Sep 1
OPO12:15 pmPorto
29h 45m
2 stops
SEA10:00 amSeattle/Tacoma Intl
$578
United Airlines
Aug 11
SEA10:40 pmSeattle/Tacoma Intl
24h 15m
2 stops
OPO6:55 amPorto
Sep 2
OPO12:35 pmPorto
19h 24m
2 stops
SEA11:59 pmSeattle/Tacoma Intl
$580

Delta flights from Seattle to Porto

Our best Delta deals on Seattle to Porto flight tickets
Delta
Apr 20
SEA6:40 pmSeattle/Tacoma Intl
19h 20m
1 stop
OPO10:00 pmPorto
Apr 29
OPO5:00 amPorto
21h 26m
2 stops
SEA6:26 pmSeattle/Tacoma Intl
$489
Delta
Apr 19
SEA5:35 pmSeattle/Tacoma Intl
16h 35m
1 stop
OPO6:10 pmPorto
Apr 29
OPO5:00 amPorto
21h 26m
2 stops
SEA6:26 pmSeattle/Tacoma Intl
$494
Delta
Apr 19
SEA6:00 amSeattle/Tacoma Intl
28h 10m
2 stops
OPO6:10 pmPorto
Apr 29
OPO5:00 amPorto
21h 26m
2 stops
SEA6:26 pmSeattle/Tacoma Intl
$499

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 February 22, 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

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

6:40 pm-10:00 pm

1 stop19h 20m

Porto

Wed 4/29

7:10 pm-11:45 am

1 stop24h 35m

$479

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

6:40 pm-10:00 pm

1 stop19h 20m

Porto

Wed 4/29

5:00 am-8:25 pm

2 stops23h 25m

$489

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

1:45 pm-10:00 pm

2 stops24h 15m

Porto

Wed 4/29

5:00 am-5:16 pm

2 stops20h 16m

$494

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sun 4/19

1:45 pm-6:10 pm

1 stop20h 25m

Porto

Wed 4/29

5:00 am-5:16 pm

2 stops20h 16m

$495

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sun 4/19

6:00 am-6:10 pm

2 stops28h 10m

Porto

Wed 4/29

5:00 am-6:26 pm

2 stops21h 26m

$499

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

10:35 pm-9:45 am

2 stops27h 10m

Porto

Wed 4/29

12:35 pm-11:37 am

2 stops31h 02m

$501

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

6:40 pm-10:00 pm

1 stop19h 20m

Porto

Sat 5/2

5:00 am-11:42 am

1 stop14h 42m

$529

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

6:40 pm-10:00 pm

1 stop19h 20m

Porto

Thu 4/30

11:25 am-11:42 am

1 stop32h 17m

$532

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 4/20

1:45 pm-10:00 pm

2 stops24h 15m

Porto

Sat 5/2

5:00 am-11:42 am

1 stop14h 42m

$533

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sun 4/19

5:35 pm-6:10 pm

1 stop16h 35m

Porto

Sat 5/2

5:00 am-11:42 am

1 stop14h 42m

$534

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 $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 $664.

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 $894 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 $740 on momondo.

Can stopping save me money on Seattle to Porto flights?

You could potentially save up to 24% 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

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
KLMPriceFrom $490Free CancellationRating
7.7
1,458 reviews
Search KLM flights
LufthansaPriceFrom $503Free CancellationRating
6.8
7,801 reviews
Search Lufthansa flights
DeltaPriceFrom $588Free CancellationRating
7.9
8,239 reviews
Search Delta flights
Air CanadaPriceFrom $660Free CancellationRating
7.1
10,738 reviews
Search Air Canada flights
United AirlinesPriceFrom $664Free CancellationRating
7.4
9,339 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
Matosinhos
Braga
Aveiro
Esposende
Lamego
Guimarães
Pinhao
Chaves
Espinho
Arcos de Valdevez
Viseu
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

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