What is the cheapest airline that flies from Seattle/Tacoma Intl to Portugal?

British Airways, United Airlines, and KLM are the most popular carriers operating from Seattle/Tacoma Intl to Portugal

What airlines fly to Portugal?

Delta, British Airways and United Airlines are the top three most popular airlines that fly to Portugal from Seattle according to our data. Delta is the first choice among our users, with 38% of people opting to fly with this airline when traveling to Portugal. Keep in mind that there are 12 different airlines that fly to Portugal on a routine basis, so you have a few additional options to choose from.

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

Prices for flights from Seattle/Tacoma Intl Airport to Portugal were last updated today.

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

The number of operators available for flights from Seattle/Tacoma Intl Airport to Portugal is 12 as of October 2026.

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

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 Portugal.

What documentation or ID do you need to fly to Portugal?

The necessary travel and health documents for your Portugal trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

$279 Cheap Flights from Seattle to Portugal in 2026/27

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Seattle to Portugal

Round-trip

One-way

Last minute

Cheap round-trip flights

Enter your travel dates to find the best prices.

2:50 pm - 12:50 pmSEA Seattle/Tacoma Intl-OPO Porto

14h 00m1 stop Munich Franz Josef Strauss

6:00 am - 2:35 pmOPO Porto-SEA Seattle/Tacoma Intl

16h 35m2 stops Frankfurt am Main Vancouver Intl

$693Multiple Airlines

Sun, Mar 7 - Wed, Mar 10

7:45 am - 6:30 pmSEA Seattle/Tacoma Intl-OPO Porto

26h 45m2 stops Toronto Pearson Intl Zurich

6:00 am - 2:35 pmOPO Porto-SEA Seattle/Tacoma Intl

16h 35m2 stops Frankfurt am Main Vancouver Intl

$700Multiple Airlines

Sun, Mar 7 - Wed, Mar 10

3:30 pm - 10:00 pmSEA Seattle/Tacoma Intl-OPO Porto

22h 30m1 stop Paris Charles de Gaulle

11:15 am - 11:35 amOPO Porto-SEA Seattle/Tacoma Intl

32h 20m1 stop Amsterdam Schiphol

$712Delta

Mon, Mar 1 - Thu, Mar 11

3:30 pm - 9:55 pmSEA Seattle/Tacoma Intl-OPO Porto

22h 25m1 stop Paris Charles de Gaulle

5:00 am - 11:35 amOPO Porto-SEA Seattle/Tacoma Intl

14h 35m1 stop Amsterdam Schiphol

$712Delta

Sun, Mar 7 - Wed, Mar 10

2:35 pm - 3:25 pmSEA Seattle/Tacoma Intl-OPO Porto

16h 50m1 stop Amsterdam Schiphol

5:00 am - 11:35 amOPO Porto-SEA Seattle/Tacoma Intl

14h 35m1 stop Amsterdam Schiphol

$717KLM

Wed, Mar 3 - Wed, Mar 10

2:50 pm - 1:15 pmSEA Seattle/Tacoma Intl-OPO Porto

14h 25m1 stop Munich Franz Josef Strauss

6:15 am - 1:00 pmOPO Porto-SEA Seattle/Tacoma Intl

14h 45m1 stop Munich Franz Josef Strauss

$721Lufthansa

Wed, Mar 3 - Fri, Mar 12

2:50 pm - 12:50 pmSEA Seattle/Tacoma Intl-OPO Porto

14h 00m1 stop Munich Franz Josef Strauss

6:15 am - 1:00 pmOPO Porto-SEA Seattle/Tacoma Intl

14h 45m1 stop Munich Franz Josef Strauss

$721Lufthansa

Sun, Mar 7 - Fri, Mar 12

7:45 am - 11:15 amSEA Seattle/Tacoma Intl-OPO Porto

43h 30m2 stops Toronto Pearson Intl Zurich

6:00 am - 2:35 pmOPO Porto-SEA Seattle/Tacoma Intl

16h 35m2 stops Frankfurt am Main Vancouver Intl

$721Air Canada

Mon, Mar 1 - Thu, Mar 11

7:45 am - 6:30 pmSEA Seattle/Tacoma Intl-OPO Porto

26h 45m2 stops Toronto Pearson Intl Zurich

6:00 am - 6:20 pmOPO Porto-SEA Seattle/Tacoma Intl

20h 20m2 stops Frankfurt am Main Vancouver Intl

$721Air Canada

Sun, Mar 7 - Wed, Mar 10

4:05 pm - 10:00 pmSEA Seattle/Tacoma Intl-OPO Porto

21h 55m1 stop Paris Charles de Gaulle

5:00 am - 11:35 amOPO Porto-SEA Seattle/Tacoma Intl

14h 35m1 stop Amsterdam Schiphol

$762KLM

Thu, Mar 4 - Thu, Mar 11

Cheap last minute flights

Enter your travel dates to find the best prices.

7:15 pm - 7:00 amSEA Seattle/Tacoma Intl-OPO Porto

27h 45m2 stops Vancouver Intl Montreal Pierre Elliott Trudeau Intl

12:15 pm - 6:32 pmOPO Porto-SEA Seattle/Tacoma Intl

38h 17m2 stops Zurich Vancouver Intl

$914Multiple Airlines

Tue, Oct 6 - Wed, Oct 14

7:15 pm - 9:45 amSEA Seattle/Tacoma Intl-OPO Porto

30h 30m1 stop Istanbul

10:55 am - 6:10 pmOPO Porto-SEA Seattle/Tacoma Intl

38h 15m1 stop Istanbul

$915Turkish Airlines

Mon, Oct 5 - Tue, Oct 27

7:00 am - 9:45 amSEA Seattle/Tacoma Intl-OPO Porto

18h 45m1 stop Newark

11:50 am - 4:03 pmOPO Porto-SEA Seattle/Tacoma Intl

36h 13m2 stops Montreal Pierre Elliott Trudeau Intl Denver Intl

$930United Airlines

Sun, Oct 4 - Thu, Oct 22

6:40 pm - 10:05 pmSEA Seattle/Tacoma Intl-OPO Porto

19h 25m1 stop Paris Charles de Gaulle

5:00 am - 4:35 pmOPO Porto-SEA Seattle/Tacoma Intl

19h 35m1 stop Amsterdam Schiphol

$931Delta

Tue, Oct 6 - Thu, Oct 22

6:40 pm - 10:05 pmSEA Seattle/Tacoma Intl-OPO Porto

19h 25m1 stop Paris Charles de Gaulle

5:00 am - 11:52 amOPO Porto-SEA Seattle/Tacoma Intl

14h 52m1 stop Amsterdam Schiphol

$931Delta

Tue, Oct 6 - Fri, Oct 23

1:30 pm - 3:25 pmSEA Seattle/Tacoma Intl-OPO Porto

17h 55m1 stop Paris Charles de Gaulle

7:10 pm - 11:52 amOPO Porto-SEA Seattle/Tacoma Intl

24h 42m1 stop Amsterdam Schiphol

$931KLM

Tue, Oct 6 - Wed, Oct 14

5:50 am - 6:30 pmSEA Seattle/Tacoma Intl-OPO Porto

28h 40m2 stops Vancouver Intl Zurich

8:40 am - 10:47 pmOPO Porto-SEA Seattle/Tacoma Intl

22h 07m2 stops Zurich Vancouver Intl

$932Air Canada

Wed, Oct 7 - Thu, Oct 22

5:07 pm - 7:00 amSEA Seattle/Tacoma Intl-OPO Porto

29h 53m2 stops Chicago O'Hare Intl Montreal Pierre Elliott Trudeau Intl

11:50 am - 4:03 pmOPO Porto-SEA Seattle/Tacoma Intl

36h 13m2 stops Montreal Pierre Elliott Trudeau Intl Denver Intl

$933United Airlines

Sun, Oct 4 - Thu, Oct 22

3:55 pm - 1:10 amSEA Seattle/Tacoma Intl-FNC Funchal Madeira

49h 15m2 stops Kastrup Copenhagen Manchester

6:05 am - 7:00 pmFNC Funchal Madeira-SEA Seattle/Tacoma Intl

20h 55m1 stop London Stansted

$978Multiple Airlines

Sun, Oct 4 - Tue, Oct 13

7:15 am - 10:25 amSEA Seattle/Tacoma Intl-OPO Porto

19h 10m1 stop New York John F Kennedy Intl

5:00 am - 11:52 amOPO Porto-SEA Seattle/Tacoma Intl

14h 52m1 stop Amsterdam Schiphol

$1,100KLM

Sun, Oct 4 - Tue, Oct 13

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

British Airways flights from Seattle to Portugal

Our best British Airways deals on Seattle to Portugal flight tickets

British Airways

Dec 10

SEA1:40 pmSeattle/Tacoma Intl

14h 25m

1 stop

LIS12:05 pmLisbon Humberto Delgado

Dec 21

LIS6:35 pmLisbon Humberto Delgado

24h 50m

1 stop

SEA11:25 amSeattle/Tacoma Intl

$818

British Airways

Dec 6

SEA6:45 pmSeattle/Tacoma Intl

36h 50m

1 stop

FNC3:35 pmFunchal Madeira

Jan 11

FNC12:30 pmFunchal Madeira

36h 20m

1 stop

SEA4:50 pmSeattle/Tacoma Intl

$997

British Airways

Oct 6

SEA8:20 pmSeattle/Tacoma Intl

18h 40m

1 stop

LIS11:00 pmLisbon Humberto Delgado

Oct 14

LIS6:45 pmLisbon Humberto Delgado

24h 50m

1 stop

SEA11:35 amSeattle/Tacoma Intl

$1,032

Air Canada flights from Seattle to Portugal

Our best Air Canada deals on Seattle to Portugal flight tickets

Air Canada

Mar 7

SEA7:45 amSeattle/Tacoma Intl

26h 45m

2 stops

OPO6:30 pmPorto

Mar 11

OPO6:00 amPorto

20h 20m

2 stops

SEA6:20 pmSeattle/Tacoma Intl

$721

Air Canada

Dec 3

SEA7:05 pmSeattle/Tacoma Intl

30h 15m

2 stops

LIS9:20 amLisbon Humberto Delgado

Dec 15

LIS12:50 pmLisbon Humberto Delgado

33h 47m

2 stops

SEA2:37 pmSeattle/Tacoma Intl

$808

Air Canada

Dec 3

SEA7:05 pmSeattle/Tacoma Intl

30h 15m

2 stops

LIS9:20 amLisbon Humberto Delgado

Dec 16

LIS11:20 amLisbon Humberto Delgado

17h 39m

1 stop

SEA8:59 pmSeattle/Tacoma Intl

$813

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 3/7

2:50 pm-12:50 pm

1 stop14h 00m

Porto

Wed 3/10

6:00 am-2:35 pm

2 stops16h 35m

$693

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 3/7

7:45 am-6:30 pm

2 stops26h 45m

Porto

Wed 3/10

6:00 am-2:35 pm

2 stops16h 35m

$700

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Mon 3/1

3:30 pm-10:00 pm

1 stop22h 30m

Porto

Thu 3/11

11:15 am-11:35 am

1 stop32h 20m

$712

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 3/7

3:30 pm-9:55 pm

1 stop22h 25m

Porto

Wed 3/10

5:00 am-11:35 am

1 stop14h 35m

$712

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Wed 3/3

2:35 pm-3:25 pm

1 stop16h 50m

Porto

Wed 3/10

5:00 am-11:35 am

1 stop14h 35m

$717

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Wed 3/3

2:50 pm-1:15 pm

1 stop14h 25m

Porto

Fri 3/12

6:15 am-1:00 pm

1 stop14h 45m

$721

Quickest round-trip

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 3/7

2:50 pm-12:50 pm

1 stop14h 00m

Porto

Fri 3/12

6:15 am-1:00 pm

1 stop14h 45m

$721

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Mon 3/1

7:45 am-11:15 am

2 stops43h 30m

Porto

Thu 3/11

6:00 am-2:35 pm

2 stops16h 35m

$721

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 3/7

7:45 am-6:30 pm

2 stops26h 45m

Porto

Wed 3/10

6:00 am-6:20 pm

2 stops20h 20m

$721

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Thu 3/4

4:05 pm-10:00 pm

1 stop21h 55m

Porto

Thu 3/11

5:00 am-11:35 am

1 stop14h 35m

$762

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Seattle to Portugal

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

Prices

Airlines

What is the cheapest month to fly to Portugal?

The cheapest month to fly to Portugal from Seattle is in January. Flight prices, which tend to average around $498, are often lower during this time because this is during the off-season. If you aren’t able to travel during the month of January, then book flights to Portugal from Seattle during February instead. Flights to Portugal in February, while not as cheap as those in January, still average around $580.

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

You are more likely to see cheaper flights to Portugal from Seattle when booking week ahead of your departure date. In general, you can expect to find flights to Portugal for around $858 when searching week out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Portugal from Seattle for as low as $778 on momondo.

Can stopping save me money on Seattle to Portugal flights?

You could potentially save up to 5% on your flight if you consider stops on a Seattle to Portugal flight.

Cheap Seattle to Portugal flight deals and tips

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

Best Price Found	$279
Fastest flight time	14h 00m
Direct flights	None

The best one-way flight to Portugal from Seattle in the past 72 hours is $279. The best round-trip flight deal from Seattle to Portugal found on momondo in the last 72 hours is $693.

The fastest flight from Seattle to Portugal takes 14h 00m

There are no direct flights from Seattle to Portugal. There are no popular flight routes from Seattle to Portugal.

Search flight deals

Frequently asked questions about flying from Seattle to Portugal

When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Portugal?
Prices for flights from Seattle/Tacoma Intl Airport to Portugal were last updated today.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Portugal?
The number of operators available for flights from Seattle/Tacoma Intl Airport to Portugal is 12 as of October 2026.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to Portugal?
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 Portugal.
What documentation or ID do you need to fly to Portugal?
The necessary travel and health documents for your Portugal trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Best airlines flying from Seattle to Portugal

Compare and see reviews for airlines that fly from Seattle to Portugal with momondo

Airline	Rating	Free Cancellation	Price
Icelandair	PriceFrom $360	Free Cancellation	Rating 6.9 756 reviews	Search Icelandair flights
Lufthansa	PriceFrom $462	Free Cancellation	Rating 6.8 8,255 reviews	Search Lufthansa flights
KLM	PriceFrom $481	Free Cancellation	Rating 7.8 1,576 reviews	Search KLM flights
British Airways	PriceFrom $482	Free Cancellation	Rating 6.7 8,244 reviews	Search British Airways flights
United Airlines	PriceFrom $482	Free Cancellation	Rating 7.4 10,285 reviews	Search United Airlines flights
American Airlines	PriceFrom $497	Free Cancellation	Rating 7.0 12,132 reviews	Search American Airlines flights
Air France	PriceFrom $504	Free Cancellation	Rating 7.5 1,649 reviews	Search Air France flights
Delta	PriceFrom $550	Free Cancellation	Rating 7.8 8,626 reviews	Search Delta flights
Scandinavian Airlines	PriceFrom $567	Free Cancellation	Rating 7.4 2,007 reviews	Search Scandinavian Airlines flights
Air Canada	PriceFrom $660	Free Cancellation	Rating 7.1 11,718 reviews	Search Air Canada flights

Why use momondo?

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

It is quick and easy to find Seattle to Portugal flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Portugal that suits you.

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

All flight searches from Seattle to Portugal on momondo can be filtered to show those which offer flexible booking policies.

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

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 Portugal.

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

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

An easier way to manage your Portugal 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.

Start using Trips

Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

1 adult

Mon 11/2

Mon 11/9

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Portugal

Popular cities

Other flights from Seattle

Other flights to Portugal

Airlines

Cabin classes

Complete your trip

Feeling lucky

Popular cities in Portugal

Flights to Lisbonfrom $398

Flights to Portofrom $406

Flights to Funchalfrom $406

Flights to Farofrom $411

Flights to Ponta Delgadafrom $557

Flights to Lajesfrom $571

Flights to Hortafrom $577

Flights to Pico Islandfrom $691

Flights to Porto Santofrom $935

Flights to Velasfrom $574

Cheap flights from Seattle to Portugal from $279

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 Portugal departing on 10/31. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Find the cheapest flights from Seattle to Portugal

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

British Airways flights from Seattle to Portugal

Our best British Airways deals on Seattle to Portugal flight tickets

Air Canada flights from Seattle to Portugal

Our best Air Canada deals on Seattle to Portugal flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Seattle to Portugal that are best for you.

See travel insights to Portugal from

How to get the cheapest flight ticket from Seattle to Portugal

What is the cheapest month to fly to Portugal?

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

Can stopping save me money on Seattle to Portugal flights?

What is the cheapest airline that flies from Seattle/Tacoma Intl to Portugal?

What airlines fly to Portugal?

Cheap Seattle to Portugal flight deals and tips

Best Price Found

Fastest flight time

Direct flights

Frequently asked questions about flying from Seattle to Portugal

Best airlines flying from Seattle to Portugal

Compare and see reviews for airlines that fly from Seattle to Portugal with momondo

Why use momondo?

An easier way to manage your Portugal 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.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to Portugal

Popular cities in Portugal

Popular flights according to clicks in the last 7 days on momondo

Seattle flight routes

According to popular flight searches on momondo this year

Portugal flight routes

According to popular flight searches on momondo this year

Fly your favorite airline to Portugal

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to Portugal

List of cabin classes available on flights landing in Portugal. Availability may vary depending on flight origin and airline.

Complete your trip to Portugal

Explore popular destinations other users love

According to popular flight searches on momondo this year