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Cheap flights from Seattle to Porto from $285

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 1/15. 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.
Multiple Airlines Logo
3:25 pm - 11:10 amSEA-OPO
35h 45m2 stops
Multiple Airlines Logo
2:05 pm - 1:20 pmOPO-SEA
31h 15m1 stop
$449Multiple Airlines
Find Deal
qui, dez 4 - qui, dez 11
Multiple Airlines Logo
1:05 pm - 11:10 amSEA-OPO
38h 05m2 stops
Multiple Airlines Logo
2:05 pm - 1:20 pmOPO-SEA
31h 15m1 stop
$450Multiple Airlines
Find Deal
qui, dez 4 - qui, dez 11
Lufthansa Logo
3:40 pm - 11:40 pmSEA-OPO
48h 00m2 stops
Lufthansa Logo
6:30 am - 1:20 pmOPO-SEA
14h 50m1 stop
$477Lufthansa
Find Deal
qui, dez 4 - sex, dez 12
KLM Logo
2:05 pm - 10:25 amSEA-OPO
36h 20m1 stop
KLM Logo
4:10 pm - 11:50 amOPO-SEA
27h 40m1 stop
$478KLM
Find Deal
qua, dez 3 - qua, dez 10
Delta Logo
7:20 am - 10:30 amSEA-OPO
19h 10m2 stops
Delta Logo
11:15 am - 11:50 amOPO-SEA
32h 35m1 stop
$481Delta
Find Deal
sex, dez 5 - qua, dez 10
Delta Logo
3:05 pm - 3:25 pmSEA-OPO
16h 20m1 stop
Delta Logo
11:15 am - 11:50 amOPO-SEA
32h 35m1 stop
$482Delta
Find Deal
qui, dez 4 - qua, dez 10
Lufthansa Logo
3:40 pm - 11:40 pmSEA-OPO
48h 00m2 stops
Lufthansa Logo
6:00 am - 8:54 pmOPO-SEA
22h 54m2 stops
$485Lufthansa
Find Deal
qui, dez 4 - qua, dez 10
KLM Logo
2:05 pm - 10:25 amSEA-OPO
36h 20m1 stop
KLM Logo
6:30 am - 10:23 pmOPO-SEA
23h 53m2 stops
$488KLM
Find Deal
qua, dez 3 - sex, dez 12
United Airlines Logo
11:59 pm - 11:40 amSEA-OPO
27h 41m2 stops
United Airlines Logo
6:00 am - 11:30 amOPO-SEA
37h 30m2 stops
$502United Airlines
Find Deal
seg, dez 29 - ter, jan 20
United Airlines Logo
8:36 am - 9:30 amSEA-OPO
16h 54m2 stops
United Airlines Logo
6:00 am - 11:15 pmOPO-SEA
25h 15m3 stops
$683United Airlines
Find Deal
qua, nov 19 - ter, dez 16

Lufthansa flights from Seattle to Porto

Our best Lufthansa deals on Seattle to Porto flight tickets
Lufthansa
Dec 4
SEA3:40 pmSeattle/Tacoma Intl
48h 00m
2 stops
OPO11:40 pmPorto
Dec 12
OPO6:30 amPorto
14h 50m
1 stop
SEA1:20 pmSeattle/Tacoma Intl
$477
Find similar
Lufthansa
Dec 4
SEA3:40 pmSeattle/Tacoma Intl
48h 00m
2 stops
OPO11:40 pmPorto
Dec 10
OPO6:00 amPorto
22h 54m
2 stops
SEA8:54 pmSeattle/Tacoma Intl
$485
Find similar
Lufthansa
Dec 4
SEA3:40 pmSeattle/Tacoma Intl
48h 00m
2 stops
OPO11:40 pmPorto
Dec 8
OPO12:30 pmPorto
31h 40m
1 stop
SEA12:10 pmSeattle/Tacoma Intl
$494
Find similar

KLM flights from Seattle to Porto

Our best KLM deals on Seattle to Porto flight tickets
KLM
Dec 3
SEA2:05 pmSeattle/Tacoma Intl
36h 20m
1 stop
OPO10:25 amPorto
Dec 10
OPO4:10 pmPorto
27h 40m
1 stop
SEA11:50 amSeattle/Tacoma Intl
$478
Find similar
KLM
Dec 3
SEA2:05 pmSeattle/Tacoma Intl
36h 20m
1 stop
OPO10:25 amPorto
Dec 12
OPO6:30 amPorto
23h 53m
2 stops
SEA10:23 pmSeattle/Tacoma Intl
$488
Find similar
KLM
Dec 2
SEA1:40 pmSeattle/Tacoma Intl
12h 50m
1 stop
OPO10:30 amPorto
Dec 11
OPO11:20 amPorto
34h 05m
1 stop
SEA1:25 pmSeattle/Tacoma Intl
$495
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 novembro 6, 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

qui 12/4

3:25 pm-11:10 am

2 stops35h 45m

Porto

qui 12/11

2:05 pm-1:20 pm

1 stop31h 15m

$449

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qui 12/4

1:05 pm-11:10 am

2 stops38h 05m

Porto

qui 12/11

2:05 pm-1:20 pm

1 stop31h 15m

$450

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qui 12/4

3:40 pm-11:40 pm

2 stops48h 00m

Porto

sex 12/12

6:30 am-1:20 pm

1 stop14h 50m

$477

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qua 12/3

2:05 pm-10:25 am

1 stop36h 20m

Porto

qua 12/10

4:10 pm-11:50 am

1 stop27h 40m

$478

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

sex 12/5

7:20 am-10:30 am

2 stops19h 10m

Porto

qua 12/10

11:15 am-11:50 am

1 stop32h 35m

$481

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qui 12/4

3:05 pm-3:25 pm

1 stop16h 20m

Porto

qua 12/10

11:15 am-11:50 am

1 stop32h 35m

$482

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qui 12/4

3:40 pm-11:40 pm

2 stops48h 00m

Porto

qua 12/10

6:00 am-8:54 pm

2 stops22h 54m

$485

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qua 12/3

2:05 pm-10:25 am

1 stop36h 20m

Porto

sex 12/12

6:30 am-10:23 pm

2 stops23h 53m

$488

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

seg 12/29

11:59 pm-11:40 am

2 stops27h 41m

Porto

ter 1/20

6:00 am-11:30 am

2 stops37h 30m

$502

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

qua 11/19

8:36 am-9:30 am

2 stops16h 54m

Porto

ter 12/16

6:00 am-11:15 pm

3 stops25h 15m

$683

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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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 October is, on average, the cheapest month to fly to Porto from Seattle, with most prices found around $734. If you aren’t able to travel during the month of October, then book flights to Porto from Seattle during March instead. Flights to Porto in March, while not as cheap as those in October, still average around $788.

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 $1,023 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 $775 on momondo.

Can stopping save me money on Seattle to Porto flights?

You could potentially save up to 6% 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 November 2025, prices for Seattle to Porto flights are approximately 86% more expensive 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.
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 $642Free CancellationRating
6.8
7,558 reviews
Search Lufthansa flights
DeltaPriceFrom $647Free CancellationRating
7.9
8,001 reviews
Search Delta flights
KLMPriceFrom $659Free CancellationRating
7.7
1,405 reviews
Search KLM flights
United AirlinesPriceFrom $679Free CancellationRating
7.4
9,004 reviews
Search United Airlines flights
Turkish AirlinesPriceFrom $685Free CancellationRating
7.3
4,032 reviews
Search Turkish 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
Aveiro
Matosinhos
Braga
Lamego
Guimarães
Esposende
Chaves
Espinho
Viseu
Ponte de Lima
Arcos de Valdevez
Pinhao
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.

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