Cheap flights from Seattle to Porto from $335
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 9/12. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
Discover deals from 900+ travel sites with momondo.
Save money when you book flights with momondo
Big names and deals
Big names and deals
Search 100s of travel sites to compare prices.Filter for what you want
Filter for what you want
Free Wi-Fi? Stopover? Instantly customize your results.Trusted and free
Trusted and free
We’re completely free to use - no hidden charges or fees.Price Alerts
Price Alerts
Not ready to book? to track prices.Find the cheapest flights from Seattle to Porto
Cheap round-trip flights
Cheap one-way flights
Cheap last minute flights
United Airlines flights from Seattle to Porto
Our best United Airlines deals on Seattle to Porto flight tickets
SWISS flights from Seattle to Porto
Our best SWISS deals on Seattle to Porto flight tickets
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 January is, on average, the cheapest month to fly to Porto from Seattle, with most prices found around $769. If you aren’t able to travel during the month of January, then book flights to Porto from Seattle during March instead. Flights to Porto in March, while not as cheap as those in January, still average around $795.
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 4 weeks ahead of your departure date. In general, you can expect to find flights to Porto for around $1,052 when searching 4 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 $895 on momondo.
What is the cheapest airline that flies from Seattle/Tacoma Intl to Porto?
Scandinavian Airlines, Air Canada, and United Airlines are the most popular carriers operating from Seattle/Tacoma Intl to Porto
What airlines fly to Porto?
KLM, United Airlines and Delta are the top three most popular airlines that fly to Porto from Seattle according to our data. KLM is the first choice among our users, with 30% of people opting to fly with this airline when traveling to Porto. Keep in mind that there are 6 different airlines that fly to Porto on a routine basis, so you have a few additional options to choose from.
When to book flights from Seattle to Porto
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
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 13h 25m 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?
As of April 2025, there are 6 operators available to choose from 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?
Based on momondo bookings for flights between Seattle and Porto, the leading airline is KLM, making up 27% of the total bookings. Other popular airlines include United Airlines with 26%, Delta with 24%, and Lufthansa with 11%.
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 | ||
|---|---|---|---|---|---|
| PriceFrom $636 | Free Cancellation | Rating 8.0 7,936 reviews | |||
| PriceFrom $649 | Free Cancellation | Rating 7.8 1,333 reviews | |||
| PriceFrom $673 | Free Cancellation | Rating 6.6 6,834 reviews | |||
| PriceFrom $697 | Free Cancellation | Rating 6.7 7,042 reviews | |||
| PriceFrom $717 | Free Cancellation | Rating 7.4 8,696 reviews | |||
| PriceFrom $765 | Free Cancellation | Rating 7.3 3,788 reviews |
Traveling to a place near Porto?
Book flights to Porto if you plan to visit one of these locationsWhy 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.