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Cheap flights from Seattle to Porto from $295

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 10/19. 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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Find the cheapest flights from Seattle to Porto (SEA-OPO)

Cheap round-trip flights

United Airlines Logo
8:36 am - 9:30 amSEA-OPO
16h 54m2 stops
United Airlines Logo
6:00 am - 12:59 amOPO-SEA
50h 59m3 stops
$596United Airlines
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Tue, Nov 18 - Tue, Nov 25
United Airlines Logo
5:05 am - 9:30 amSEA-OPO
20h 25m2 stops
United Airlines Logo
12:35 pm - 10:41 pmOPO-SEA
18h 06m1 stop
$603United Airlines
Find Deal
Tue, Nov 18 - Tue, Nov 25
Logo
6:20 am - 9:30 amSEA-OPO
19h 10m1 stop
Logo
12:30 pm - 12:10 pmOPO-SEA
31h 40m1 stop
$609
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Wed, Nov 12 - Thu, Nov 27
Turkish Airlines Logo
7:10 pm - 9:50 amSEA-OPO
30h 40m1 stop
Turkish Airlines Logo
4:50 pm - 10:35 amOPO-SEA
25h 45m1 stop
$650Turkish Airlines
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Sun, Sep 21 - Wed, Oct 8
Turkish Airlines Logo
7:10 pm - 9:50 amSEA-OPO
30h 40m1 stop
Turkish Airlines Logo
4:50 pm - 5:15 pmOPO-SEA
32h 25m1 stop
$668Turkish Airlines
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Mon, Sep 22 - Thu, Oct 9
Lufthansa Logo
2:20 pm - 10:45 pmSEA-OPO
24h 25m1 stop
Lufthansa Logo
6:00 am - 6:49 pmOPO-SEA
20h 49m2 stops
$732Lufthansa
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Thu, Oct 16 - Thu, Oct 23
Lufthansa Logo
6:50 pm - 11:20 pmSEA-OPO
20h 30m1 stop
Lufthansa Logo
6:00 am - 11:55 amOPO-SEA
13h 55m1 stop
$733Lufthansa
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Wed, Sep 24 - Tue, Sep 30
Delta Logo
6:45 pm - 8:25 amSEA-OPO
29h 40m1 stop
Delta Logo
4:20 pm - 5:40 pmOPO-SEA
33h 20m1 stop
$786Delta
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Wed, Sep 17 - Wed, Oct 1
Delta Logo
6:45 pm - 8:25 amSEA-OPO
29h 40m1 stop
Delta Logo
4:20 pm - 4:59 pmOPO-SEA
32h 39m2 stops
$796Delta
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Wed, Sep 17 - Tue, Sep 30
KLM Logo
2:10 pm - 10:15 pmSEA-OPO
24h 05m1 stop
KLM Logo
4:20 pm - 11:15 amOPO-SEA
26h 55m1 stop
$815KLM
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Wed, Sep 17 - Mon, Sep 22

Air Canada flights from Seattle to Porto

Our best Air Canada deals on Seattle to Porto flight tickets
Air Canada
Oct 16
SEA10:00 amSeattle/Tacoma Intl
24h 30m
2 stops
OPO6:30 pmPorto
Oct 23
OPO6:00 amPorto
20h 36m
2 stops
SEA6:36 pmSeattle/Tacoma Intl
$730
Find similar
Air Canada
Sep 21
SEA7:15 pmSeattle/Tacoma Intl
30h 20m
2 stops
OPO9:35 amPorto
Sep 28
OPO8:40 amPorto
21h 36m
2 stops
SEA10:16 pmSeattle/Tacoma Intl
$802
Find similar
Air Canada
Sep 6
SEA7:15 pmSeattle/Tacoma Intl
54h 20m
2 stops
OPO9:35 amPorto
Sep 21
OPO11:20 amPorto
34h 56m
2 stops
SEA2:16 pmSeattle/Tacoma Intl
$1,313
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Lufthansa flights from Seattle to Porto

Our best Lufthansa deals on Seattle to Porto flight tickets
Lufthansa
Oct 16
SEA2:20 pmSeattle/Tacoma Intl
24h 25m
1 stop
OPO10:45 pmPorto
Oct 23
OPO6:00 amPorto
20h 49m
2 stops
SEA6:49 pmSeattle/Tacoma Intl
$732
Find similar
Lufthansa
Sep 24
SEA6:50 pmSeattle/Tacoma Intl
20h 30m
1 stop
OPO11:20 pmPorto
Sep 30
OPO6:00 amPorto
13h 55m
1 stop
SEA11:55 amSeattle/Tacoma Intl
$733
Find similar
Lufthansa
Oct 1
SEA2:20 pmSeattle/Tacoma Intl
24h 25m
1 stop
OPO10:45 pmPorto
Oct 15
OPO6:00 amPorto
20h 49m
2 stops
SEA6:49 pmSeattle/Tacoma Intl
$756
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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 August 24, 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 11/18

8:36 am-9:30 am

2 stops16h 54m

Porto

Tue 11/25

6:00 am-12:59 am

3 stops50h 59m

$596

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 11/18

5:05 am-9:30 am

2 stops20h 25m

Porto

Tue 11/25

12:35 pm-10:41 pm

1 stop18h 06m

$603

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 11/12

6:20 am-9:30 am

1 stop19h 10m

Porto

Thu 11/27

12:30 pm-12:10 pm

1 stop31h 40m

$609

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sun 9/21

7:10 pm-9:50 am

1 stop30h 40m

Porto

Wed 10/8

4:50 pm-10:35 am

1 stop25h 45m

$650

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Mon 9/22

7:10 pm-9:50 am

1 stop30h 40m

Porto

Thu 10/9

4:50 pm-5:15 pm

1 stop32h 25m

$668

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Thu 10/16

2:20 pm-10:45 pm

1 stop24h 25m

Porto

Thu 10/23

6:00 am-6:49 pm

2 stops20h 49m

$732

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 9/24

6:50 pm-11:20 pm

1 stop20h 30m

Porto

Tue 9/30

6:00 am-11:55 am

1 stop13h 55m

$733

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 9/17

6:45 pm-8:25 am

1 stop29h 40m

Porto

Wed 10/1

4:20 pm-5:40 pm

1 stop33h 20m

$786

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 9/17

6:45 pm-8:25 am

1 stop29h 40m

Porto

Tue 9/30

4:20 pm-4:59 pm

2 stops32h 39m

$796

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 9/17

2:10 pm-10:15 pm

1 stop24h 05m

Porto

Mon 9/22

4:20 pm-11:15 am

1 stop26h 55m

$815

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 March is, on average, the cheapest month to fly to Porto from Seattle, with most prices found around $788. If you aren’t able to travel during the month of March, then book flights to Porto from Seattle during October instead. Flights to Porto in October, while not as cheap as those in March, still average around $823.

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 $1,026 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 $805 on momondo.

Can stopping save me money on Seattle to Porto flights?

You could potentially save up to 9% on your flight if you consider stops on a Seattle to Porto flight.

How have Seattle to Porto flight prices changed over time?

As of August 2025, prices for Seattle to Porto flights are approximately 12% cheaper when compared to flights at the same time last year.

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

Direct flights

None
There are no direct flights from Seattle to Porto. There are no popular flight routes from Seattle to Porto.
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  • 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 15h 35m 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
DeltaPriceFrom $647Free CancellationRating
7.9
7,980 reviews
Search Delta flights
KLMPriceFrom $649Free CancellationRating
7.8
1,386 reviews
Search KLM flights
British AirwaysPriceFrom $673Free CancellationRating
6.7
7,302 reviews
Search British Airways flights
Turkish AirlinesPriceFrom $685Free CancellationRating
7.3
3,953 reviews
Search Turkish Airlines flights
LufthansaPriceFrom $696Free CancellationRating
6.8
7,351 reviews
Search Lufthansa flights
United AirlinesPriceFrom $707Free CancellationRating
7.4
8,937 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
Aveiro
Coimbra
Braga
Matosinhos
Caminha
Guimarães
Lamego
Esposende
Chaves
Arcos de Valdevez
Espinho
Viseu
Ponte de Lima
Pinhao
Santa Maria da Feira
Curia
Penafiel
Mesao Frio
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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