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Cheap flights from Seattle to Porto from C$ 474

SEA — OPO
31 Oct — 7 Nov1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Seattle to Porto

Enter your travel dates to find the best prices.

Cheapest flights from Seattle to Porto

Tue 1/127:00 a.m. -
1 stop18h 30m
Wed 9/126:00 a.m. -
2 stops35h 32m
Deal found 1/10C$ 1,044
Mon 23/113:25 p.m. -
1 stop22h 35m
Mon 7/1211:15 a.m. -
1 stop32h 35m
Deal found 29/9C$ 1,045
Wed 25/117:15 a.m. -
1 stop17h 00m
Wed 9/125:00 a.m. -
1 stop14h 50m
Deal found 29/9C$ 1,047
Tue 24/114:05 p.m. -
1 stop34h 30m
Tue 8/125:00 a.m. -
1 stop14h 50m
Deal found 29/9C$ 1,048
Mon 23/1110:52 p.m. -
2 stops27h 43m
Wed 9/125:00 a.m. -
1 stop14h 50m
Deal found 29/9C$ 1,052
Tue 24/1111:47 p.m. -
2 stops24h 28m
Wed 9/1211:15 a.m. -
1 stop32h 35m
Deal found 29/9C$ 1,054
Mon 23/113:25 p.m. -
1 stop22h 35m
Fri 4/125:55 a.m. -
1 stop17h 18m
Deal found 29/9C$ 1,057
Tue 24/114:05 p.m. -
1 stop34h 30m
Fri 4/125:55 a.m. -
1 stop17h 18m
Deal found 29/9C$ 1,058
Mon 23/116:30 a.m. -
1 stop19h 00m
Wed 9/1212:35 p.m. -
2 stops29h 09m
Deal found 29/9C$ 1,059
Sat 14/113:48 p.m. -
1 stop32h 27m
Wed 25/1111:15 a.m. -
1 stop32h 32m
Deal found 29/9C$ 1,064
Tue 1/127:00 a.m. -
2 stops18h 30m
Wed 9/126:00 a.m. -
3 stops25h 44m
Deal found 1/10C$ 1,065

Find flight deals from Seattle to Porto

Round-trip from

C$ 1,011

One-way from

C$ 474

Popular in

December

Cheapest in

January

Average price

C$ 1,204
Delta
  • Delta
  • 1/3-11/3
  • 2 total stops
  • 54h 50m total
  • Seattle to Porto
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United Airlines
  • United Airlines
  • 17/3-31/12
  • 2 total stops
  • 20h 01m total
  • Seattle to Porto
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Highest demand for flights based on searches. 2% potential increase in price (C$ 40 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease (C$ 100 potential savings vs. average RT price).
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Average for round-trip flights in October 2026
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Cheapflights Fare Finder

 
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

Cheapest round-trip

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Wed 17/3

6:29 a.m.-9:30 a.m.

2 stops20h 01m

Porto

Wed 31/12

12:00 a.m.-3:00 p.m.

Nonstop0h 00m

C$ 474

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Tue 16/3

6:50 a.m.-9:30 a.m.

1 stop19h 40m

Porto

Wed 31/12

12:00 a.m.-3:00 p.m.

Nonstop0h 00m

C$ 474
Quickest round-trip

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 28/2

7:00 a.m.-9:30 a.m.

1 stop18h 30m

Porto

Wed 31/12

12:00 a.m.-3:00 p.m.

Nonstop0h 00m

C$ 474

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Wed 3/2

8:30 a.m.-11:00 a.m.

3 stops18h 30m

Porto

Wed 31/12

12:00 a.m.-3:00 p.m.

Nonstop0h 00m

C$ 676

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sun 18/10

6:40 p.m.-10:00 p.m.

1 stop19h 20m

Porto

Wed 31/12

12:00 a.m.-3:00 p.m.

Nonstop0h 00m

C$ 826

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Tue 13/10

12:00 p.m.-7:00 a.m.

3 stops35h 00m

Porto

Wed 31/12

12:00 a.m.-3:00 p.m.

Nonstop0h 00m

C$ 832

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Sat 6/3

9:55 p.m.-10:35 a.m.

2 stops28h 40m

Porto

Tue 9/3

11:15 a.m.-11:35 a.m.

1 stop32h 20m

C$ 1,018

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Wed 25/11

6:30 a.m.-9:30 a.m.

1 stop19h 00m

Porto

Tue 8/12

12:35 p.m.-10:27 p.m.

1 stop17h 52m

C$ 1,072

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Mon 11/1

3:25 p.m.-10:00 p.m.

1 stop22h 35m

Porto

Mon 25/1

5:00 a.m.-11:49 a.m.

1 stop14h 49m

C$ 1,082

SeattlePorto

SEA Seattle/Tacoma Intl - OPO Porto

SEAOPO

Seattle/Tacoma Intl

Mon 1/3

3:30 p.m.-10:00 p.m.

1 stop22h 30m

Porto

Sat 13/3

5:55 a.m.-1:50 p.m.

1 stop15h 55m

C$ 1,093

Flights are sorted by cheapest round-trip flights first.

Deals found on 27/9

Showing 1-10 of 16 resultsSorted by cheapest first
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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

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?

The best time to book flights from Seattle to Porto is 44 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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 C$ 707). Flying from Seattle to Porto in December is currently the most expensive (average of C$ 2,039). 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.

How much does it cost to fly round-trip from Seattle to Porto?

Airfare is below average for this route at the moment.

Seattle to Porto flights typically cost between C$ 1,076 and C$ 1,285 in March.
The cheapest round-trip price found within the last 5 days was C$ 1,011 on Delta (1 Mar-11 Mar).

Related info for your journey

  • How long is the flight from Seattle to Porto?

    For as low as C$ 1,132, Delta can have you in Porto from Seattle in 17h. Airlines will cover a distance of 8180 km. This flight may include one or multiple stops.

  • 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 C$ 707). Flying from Seattle to Porto in December is currently the most expensive (average of C$ 2,039). 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

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Alternative routes for Seattle to Porto

Seattle to Lisbon flights

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