How long is the flight from Seattle to Porto?

A quick flight from Seattle to Porto can take about 12h 50m. KLM provides one of the quickest options available for as low as $530. Airlines will cover a distance of 5083 mi. Both multi-stop and nonstop flights can be found to your destination and back.

What are the cheapest airlines flying from Seattle to Porto round-trip?

Our cheapest airline available from Seattle to Porto is Delta. Our recent data shows that you can find tickets from as low as $647 on this airline. Additional options worth looking into are KLM and Turkish Airlines, starting at $659 and $685 round-trip. Users have found that Delta is 37% cheaper than the other options available to this destination.

What is the cheapest day to fly from Seattle to Porto?

Travelers seeking maximum savings on their Seattle to Porto flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

In terms of precipitation, rainfall in Porto ranges from 0.7 - 7.7 inches per month. December is typically the wettest month, when rainfall can reach 7.7 in. July is typically the driest time to visit Porto when rainfall is around 0.7 in.

If weather is an important factor for your trip to Porto, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 68.0 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 48.2 F).

What are the most popular airlines that fly from Seattle to Porto?

When booking a flight from Seattle to Porto, you may want to consider flying on British Airways, Delta or KLM as they are the most popular for this route.

Most accurate provider : When it comes to deals on Seattle-Porto flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Porto flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Porto flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Seattle-Porto flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Porto flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Can I find deals for flights from Seattle to Porto that include hotel bookings?

Yes. In addition to deals on Seattle to Porto flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Seattle to Porto?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Porto.

Can I find deals for business class flights from Seattle to Porto?

Yes. Cheapflights offers flight deals from Seattle to Porto by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$299+ Cheap Flights from Seattle to Porto

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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Porto are usually found in October or March, booked 31 days in advance, depart on a Tuesday or Monday and return on a Monday

Cheap flight deals from Seattle to Porto

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Round-trip from	$530 (KLM)
One-way from	$299 (Mytrip)
Popular in	June
Cheapest in	October
Average price	$768

Provider with most accurate pricing for Seattle/Tacoma Intl-Porto flight deals.

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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Porto flights.

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From Seattle/Tacoma Intl to Porto

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One-way flight from Seattle/Tacoma Intl to Porto

Search Deals

Highest demand for flights based on searches. 17% potential increase in price ($217 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease ($28 potential savings vs. average RT price).

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Average for round-trip flights in October 2025

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Find flight deals from Seattle to Porto

Cheapest flights from Seattle to Porto
Explore the most affordable flight options available from Seattle to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 1, 2025.

Tue 12/21:40 pmSEA - OPO

1 stop12h 50mKLM

Thu 12/114:10 pmOPO - SEA

1 stop27h 40mKLM

Deal found 9/29

$530

Tue 12/29:30 amSEA - OPO

2 stops17h 00mMultiple Airlines

Thu 12/1111:15 amOPO - SEA

1 stop32h 35mMultiple Airlines

Deal found 9/29

$535

Fri 11/142:00 pmSEA - OPO

1 stop24h 25mLufthansa

Fri 11/216:30 amOPO - SEA

1 stop14h 50mLufthansa

Deal found 9/30

$567

Fri 11/142:00 pmSEA - OPO

1 stop24h 25mMultiple Airlines

Fri 11/216:00 amOPO - SEA

2 stops24h 16mMultiple Airlines

Deal found 9/30

$576

Fri 11/149:30 amSEA - OPO

2 stops17h 00mDelta

Fri 11/216:30 amOPO - SEA

2 stops25h 31mDelta

Deal found 9/29

$595

Fri 10/314:10 pmSEA - OPO

1 stop24h 30mLufthansa

Wed 11/194:15 pmOPO - SEA

1 stop27h 55mLufthansa

Deal found 10/1

$598

Fri 10/317:50 pmSEA - OPO

2 stops28h 50mBritish Airways

Wed 11/198:40 pmOPO - SEA

2 stops34h 38mBritish Airways

Deal found 10/1

$637

Best flights from Seattle to Porto
Discover carefully curated flight deals from Seattle to Porto that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 1, 2025.

Tue 12/21:40 pmSEA - OPO

1 stop12h 50mKLM

Thu 12/114:10 pmOPO - SEA

1 stop27h 40mKLM

Deal found 9/29

$530

Fri 11/148:00 amSEA - OPO

2 stops17h 30mMultiple Airlines

Fri 11/2112:30 pmOPO - SEA

2 stops20h 29mMultiple Airlines

Deal found 9/30

$580

Wed 10/227:10 pmSEA - OPO

1 stop30h 35mTurkish Airlines

Fri 10/314:10 pmOPO - SEA

1 stop32h 55mTurkish Airlines

Deal found 9/29

$693

Wed 10/2212:00 pmSEA - OPO

1 stop13h 45mUnited Airlines

Fri 10/316:00 amOPO - SEA

2 stops36h 45mUnited Airlines

Deal found 9/29

$707

Sat 10/187:10 pmSEA - OPO

1 stop36h 40mTurkish Airlines

Sun 11/210:55 amOPO - SEA

1 stop38h 10mTurkish Airlines

Deal found 10/1

$762

Thu 10/238:30 amSEA - OPO

2 stops17h 15mUnited Airlines

Mon 10/2712:30 pmOPO - SEA

1 stop31h 40mUnited Airlines

Deal found 9/29

$766

Sat 10/1811:40 pmSEA - OPO

2 stops26h 05mMultiple Airlines

Sun 11/25:15 amOPO - SEA

1 stop15h 05mMultiple Airlines

Deal found 10/1

$779

Sat 10/187:10 pmSEA - OPO

1 stop30h 45mTurkish Airlines

Sun 11/94:10 pmOPO - SEA

1 stop32h 55mTurkish Airlines

Deal found 9/29

$789

Wed 10/1510:50 amSEA - OPO

3 stops38h 55mUnited Airlines

Wed 10/296:00 amOPO - SEA

2 stops36h 43mUnited Airlines

Deal found 9/30

$821

Mon 11/248:10 amSEA - OPO

2 stops22h 50mMultiple Airlines

Sun 11/3011:00 amOPO - SEA

3 stops35h 20mMultiple Airlines

Deal found 9/30

$849

Sat 11/157:00 pmSEA - OPO

1 stop36h 10mTurkish Airlines

Wed 11/194:10 pmOPO - SEA

1 stop32h 55mTurkish Airlines

Deal found 9/30

$810

Sat 10/1811:10 pmSEA - OPO

2 stops26h 35mUnited Airlines

Sun 11/25:00 amOPO - SEA

2 stops35h 50mUnited Airlines

Deal found 10/1

$848

Last-minute flights from Seattle to Porto
Discover last-minute flight deals from Seattle to Porto. Data last updated October 1, 2025 and is based on user searches.

Fri 10/314:10 pmSEA - OPO

1 stop24h 30mLufthansa

Wed 11/194:15 pmOPO - SEA

1 stop27h 55mLufthansa

Deal found 10/1

$598

Fri 10/317:50 pmSEA - OPO

2 stops28h 50mBritish Airways

Wed 11/198:40 pmOPO - SEA

2 stops34h 38mBritish Airways

Deal found 10/1

$637

Fri 11/142:00 pmSEA - OPO

1 stop24h 25mLufthansa

Fri 11/216:30 amOPO - SEA

1 stop14h 50mLufthansa

Deal found 9/30

$567

Fri 11/142:00 pmSEA - OPO

1 stop24h 25mMultiple Airlines

Fri 11/216:00 amOPO - SEA

2 stops24h 16mMultiple Airlines

Deal found 9/30

$576

Fri 11/149:30 amSEA - OPO

2 stops17h 00mDelta

Fri 11/216:30 amOPO - SEA

2 stops25h 31mDelta

Deal found 9/29

$595

Mon 11/248:10 amSEA - OPO

2 stops20h 40mAir Canada

Sun 11/306:15 amOPO - SEA

2 stops23h 51mAir Canada

Deal found 9/30

$667

One-way flights from Seattle to Porto
Search for one-way flight options from Seattle to Porto. Find affordable one-way fares based on user searches. Data last updated October 1, 2025.

Mon 11/243:10 pmSEA - OPO

2 stops20h 20mMultiple Airlines

Deal found 9/30

$299

Mon 11/1711:10 pmSEA - OPO

2 stops27h 00mMultiple Airlines

Deal found 9/30

$300

Sat 10/181:50 pmSEA - OPO

2 stops39h 20mMultiple Airlines

Deal found 10/1

$319

Sun 12/1410:40 amSEA - OPO

2 stops22h 05mScandinavian Airlines

Deal found 9/28

$335

Fri 10/1710:16 amSEA - OPO

3 stops44h 44mMultiple Airlines

Deal found 10/1

$366

Sun 12/1412:25 pmSEA - OPO

3 stops37h 00mMultiple Airlines

Deal found 9/28

$374

Sat 12/1311:05 pmSEA - OPO

2 stops55h 05mMultiple Airlines

Deal found 9/28

$400

Fly from

Fly to

Route

Depart

Return

Price

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Tue 12/2

1:40 pm-10:30 am

1 stop12h 50m

Porto

Thu 12/11

4:10 pm-11:50 am

1 stop27h 40m

$530

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Fri 11/14

8:00 am-9:30 am

2 stops17h 30m

Porto

Fri 11/21

12:30 pm-12:59 am

2 stops20h 29m

$580

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 10/22

7:10 pm-9:45 am

1 stop30h 35m

Porto

Fri 10/31

4:10 pm-6:05 pm

1 stop32h 55m

$693

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 10/22

12:00 pm-9:45 am

1 stop13h 45m

Porto

Fri 10/31

6:00 am-11:45 am

2 stops36h 45m

$707

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 10/18

7:10 pm-3:50 pm

1 stop36h 40m

Porto

Sun 11/2

10:55 am-5:05 pm

1 stop38h 10m

$762

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Thu 10/23

8:30 am-9:45 am

2 stops17h 15m

Porto

Mon 10/27

12:30 pm-1:10 pm

1 stop31h 40m

$766

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 10/18

11:40 pm-9:45 am

2 stops26h 05m

Porto

Sun 11/2

5:15 am-1:20 pm

1 stop15h 05m

$779

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 10/18

7:10 pm-9:55 am

1 stop30h 45m

Porto

Sun 11/9

4:10 pm-5:05 pm

1 stop32h 55m

$789

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Sat 11/15

7:00 pm-3:10 pm

1 stop36h 10m

Porto

Wed 11/19

4:10 pm-5:05 pm

1 stop32h 55m

$810

SeattlePorto

SEA - OPO

SEAOPO

Seattle/Tacoma Intl

Wed 10/15

10:50 am-9:45 am

3 stops38h 55m

Porto

Wed 10/29

6:00 am-11:43 am

2 stops36h 43m

$821

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/1

Showing 1-10 of 20 results

Compare providers for flights from Seattle to Porto

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Porto in October.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy2 stars	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*3 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
AranGrant	Price Accuracy3 stars	Trust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on Seattle-Porto flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-Porto flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-Porto flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Seattle-Porto flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-Porto flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Seattle to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from Seattle with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Porto

How far ahead should I book a flight from Seattle to Porto?

Booking 31 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to Porto. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Seattle to Porto?

Currently, January is the cheapest month in which you can book a flight from Seattle to Porto (average of $523). Flying from Seattle to Porto in June is currently the most expensive (average of $1,027). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to OPO?

It’s optimal to fly from Seattle to Porto in the evening. By choosing this option you can save up to 26% on the cost of your flight, compared to a flight in the morning.

Reviews of airlines servicing Porto

Peruse reviews from past customers who have flown with Delta, KLM, and United Airlines from Seattle to Porto to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Delta

8.0

Very good

7,961 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

KLM

7.8

Good

1,389 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

United Airlines

7.4

Good

8,929 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Turkish Airlines

7.3

Good

3,984 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Lufthansa

6.8

Okay

7,443 reviews

Delta

8.0

Very good

7,961 reviews

Reviews

1 / 20

10.0

Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

Related info for your journey

How long is the flight from Seattle to Porto?
A quick flight from Seattle to Porto can take about 12h 50m. KLM provides one of the quickest options available for as low as $530. Airlines will cover a distance of 5083 mi. Both multi-stop and nonstop flights can be found to your destination and back.
What are the cheapest airlines flying from Seattle to Porto round-trip?
Our cheapest airline available from Seattle to Porto is Delta. Our recent data shows that you can find tickets from as low as $647 on this airline. Additional options worth looking into are KLM and Turkish Airlines, starting at $659 and $685 round-trip. Users have found that Delta is 37% cheaper than the other options available to this destination.
Can I find deals for flights from Seattle to Porto that include hotel bookings?
Yes. In addition to deals on Seattle to Porto flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Seattle to Porto?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Porto.
Can I find deals for business class flights from Seattle to Porto?
Yes. Cheapflights offers flight deals from Seattle to Porto by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Seattle to Porto?
Currently, January is the cheapest month in which you can book a flight from Seattle to Porto (average of $523). Flying from Seattle to Porto in June is currently the most expensive (average of $1,027). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Aveiro

Arcos de Valdevez

Coimbra

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Other flights to Porto

Top 6 airlines flying from Seattle to Porto

Airline	Cheapest	Average	Flexibility	On-time
Delta	Cheapest$647	Average$1,022	FlexibilityNo cancel fee	On-timeN/A
KLM	Cheapest$659	Average$1,053	FlexibilityNo cancel fee	On-time75%
Turkish Airlines	Cheapest$685	Average$833	FlexibilityNo cancel fee	On-time77%
Lufthansa	Cheapest$693	Average$979	FlexibilityNo cancel fee	On-time76%
United Airlines	Cheapest$707	Average$1,199	FlexibilityNo cancel fee	On-time69%
British Airways	Cheapest$741	Average$1,174	FlexibilityNo cancel fee	On-time70%

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$299+ Cheap flights from Seattle (SEA) to Porto (OPO)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/24. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Seattle to Porto with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Porto are usually found in October or March, booked 31 days in advance, depart on a Tuesday or Monday and return on a Monday

Cheap flight deals from Seattle to Porto

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Find flight deals from Seattle to Porto

Cheapest flights from Seattle to PortoExplore the most affordable flight options available from Seattle to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 1, 2025.

Explore the most affordable flight options available from Seattle to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 1, 2025.

Cheapflights Fare Finder

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

Compare providers for flights from Seattle to Porto

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to Porto in October.

Best time to book a flight from Seattle to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from Seattle with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Porto

How far ahead should I book a flight from Seattle to Porto?

What is the cheapest month to book a flight from Seattle to Porto?

What is the cheapest time of day to fly from SEA to OPO?

Reviews of airlines servicing Porto

Get insights into the airlines that provide service to Porto. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Porto. Reviews last updated October 1, 2025.

Peruse reviews from past customers who have flown with Delta, KLM, and United Airlines from Seattle to Porto to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Porto. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

How long is the flight from Seattle to Porto?

What are the cheapest airlines flying from Seattle to Porto round-trip?

Can I find deals for flights from Seattle to Porto that include hotel bookings?

How can I find direct flights from Seattle to Porto?

Can I find deals for business class flights from Seattle to Porto?

What is the cheapest month to book a flight from Seattle to Porto?

Traveling to a place near Porto?

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Seattle to Porto

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Top 6 airlines flying from Seattle to Porto

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Cheapest flights from Seattle to Porto
Explore the most affordable flight options available from Seattle to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 1, 2025.