OPO - SFO

$355 Find Cheap Flights from Porto to San Francisco

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Porto to San Francisco departing on 1/29. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to San Francisco

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Porto to San Francisco, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Porto to San Francisco, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$615
Overall average: $664
TAP AIR PORTUGAL
Thu 1/15Wed 1/28
OPO - SFO • 1 stop
Cheapest one-way
$355
Typical prices: $686-$785
Multiple Airlines
Thu 1/29
OPO - SFO • 3 stops
Top airlines
British Airways
Cheapest • from $651 (round-trip)
Lufthansa
Best reviews • 6.8 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to travel
September
Cheapest • 18% price drop
December
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to San Francisco!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Porto to San Francisco (OPO-SFO)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Porto to San Francisco that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Porto to San Francisco

Thu, Jan 15 - Wed, Jan 28
TAP AIR PORTUGAL Logo
6:00 pm - 4:05 pmOPO-SFO
30h 05m1 stop
TAP AIR PORTUGAL Logo
4:35 pm - 11:00 amSFO-OPO
34h 25m1 stop
$615TAP AIR PORTUGAL
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Fri, May 15 - Mon, May 18
American Airlines Logo
12:25 pm - 9:34 amOPO-SFO
29h 09m2 stops
American Airlines Logo
4:35 pm - 8:00 pmSFO-OPO
19h 25m2 stops
$638American Airlines
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Thu, Jan 15 - Wed, Jan 28
British Airways Logo
12:25 pm - 12:47 amOPO-SFO
20h 22m2 stops
British Airways Logo
11:48 am - 4:45 pmSFO-OPO
20h 57m2 stops
$651British Airways
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Wed, Jan 21 - Sun, Jan 25
American Airlines Logo
8:20 am - 12:47 amOPO-SFO
24h 27m2 stops
American Airlines Logo
6:00 am - 11:45 amSFO-OPO
21h 45m2 stops
$652American Airlines
Find Deal
Fri, May 15 - Mon, May 18
American Airlines Logo
12:25 pm - 4:10 pmOPO-SFO
35h 45m1 stop
American Airlines Logo
2:46 pm - 4:00 pmSFO-OPO
17h 14m2 stops
$673American Airlines
Find Deal
Thu, Jan 15 - Wed, Jan 28
British Airways Logo
5:35 pm - 3:00 pmOPO-SFO
29h 25m1 stop
British Airways Logo
10:30 pm - 5:15 pmSFO-OPO
34h 45m2 stops
$679British Airways
Find Deal
Fri, May 15 - Mon, May 18
Scandinavian Airlines Logo
5:55 pm - 2:40 pmOPO-SFO
28h 45m1 stop
Scandinavian Airlines Logo
4:45 pm - 11:00 amSFO-OPO
34h 15m1 stop
$687Scandinavian Airlines
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Thu, Jan 15 - Wed, Jan 28
Lufthansa Logo
6:00 am - 3:55 pmOPO-SFO
17h 55m1 stop
Lufthansa Logo
1:30 pm - 1:15 pmSFO-OPO
15h 45m1 stop
$690Lufthansa
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Mon, Dec 22 - Sun, Jan 11
SWISS Logo
7:20 pm - 4:30 pmOPO-SFO
29h 10m1 stop
SWISS Logo
7:25 pm - 11:15 amSFO-OPO
31h 50m1 stop
$695SWISS
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Mon, Dec 22 - Fri, Jan 9
Multiple Airlines Logo
7:20 pm - 4:30 pmOPO-SFO
29h 10m1 stop
Multiple Airlines Logo
2:40 pm - 10:25 pmSFO-OPO
23h 45m1 stop
$700Multiple Airlines
Find Deal
Booking Insights

KAYAK's insights & trends for Porto to San Francisco flights

Get data-powered insights and trends into flights from Porto to San Francisco to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Porto to San Francisco?

The average price of all round-trip flights from Porto to San Francisco clicked on KAYAK for each day over the last 12 months.

Your flight ticket price will generally be cheaper if you fly to San Francisco on a Wednesday and more expensive on a Saturday. On your return trip to Porto, you should consider flying back on a Thursday, and avoid Wednesdays for better deals.

What is the cheapest month to fly from Porto to San Francisco?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Porto to San Francisco, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Porto to San Francisco is September, where tickets cost $652 (return) on average. On the other hand, the most expensive months are December and October, where the average cost of round-trip tickets is $904 and $896 respectively.

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Good to know

Low seasonMay
Cheapest flight$355
Best time to beat the crowds with an average 5% drop in price.
Most popular time to fly with an average 13% increase in price.
Flight from Porto to San Francisco

When to book flights from Porto to San Francisco

Are your dates flexible? Find out the best times to travel from Porto to San Francisco based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Porto to San Francisco

  • What is the cheapest flight from Porto to San Francisco?

    In the last 3 days, the lowest price for a flight from Porto to San Francisco was $355 for a one-way ticket and $615 for a round-trip.

  • Do I need a passport to fly between Porto and San Francisco?

    A passport is required to fly from Porto to San Francisco.

  • Which aircraft models fly most regularly from Porto to San Francisco?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Porto to San Francisco?

    Star Alliance is the only airline alliance operating flights between Porto and San Francisco.

  • How does KAYAK find such low prices on flights from Porto to San Francisco?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Porto to San Francisco.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Porto to San Francisco?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to San Francisco from Porto is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Porto to San Francisco?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to San Francisco with an airline and back to Porto with another airline. Booking your flights between Porto and SFO can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Porto to San Francisco?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to San Francisco from Porto up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airline flying from Porto to San Francisco

 
See real verified KAYAK customer reviews for airlines flying from Porto to San Francisco. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Porto to San Francisco? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
6.8
LufthansaOverall score based on 7591 reviews
6.3Food
6.8Comfort
6.4Entertainment
7.0Boarding
7.6Crew
Airline reviews

Had a few open seats and could use it for a great rest ful journey

10.0 ExcellentAnonymous, Nov 2025FRA - IAD
Read more Lufthansa reviews

Had a few open seats and could use it for a great rest ful journey

It was very good. Service was friendly and efficient, and food was good.

Airline food is airline food, but the plane was wonderful and the seating comfort outstanding. One of my best flights in quite a while.

Crew was outstanding, helpful and friendly. Food is deteriorating. The snack at the end of the flight was not good, a greasy moosh of toast cheese snd other unidentifiable ingredients. Coming from Germany a pretzl with butter would have been better. Entertainment had a great selection.

Smooth flight with enough time for connection. Ran out of meal options. In-flight and gate staff were friendly and helpful. Good service overall.

The seat space seemed small especially when the person ahead reclined but other than that, very good.

Luggage transfer in Chicago was not performed in time. I received my luggage at my destination two days later.

Give yourself over 2+ hours layover because if flight is slighlty delayed and you miss your connection, Lufthansa will do nothing for you

We would have missed our connection from Munich to Boston but we had a van outside the plan that wisked us to our terminal. Much appreciated and we didn’t even realize that Lufthansa had done this until the announcement on disembarkation. Well organized airline! Will definitely fly Lufthansa again!!!

Everything went well. I will fly with Lufthansa again. And use Kayak whenever I book flights

Everything you need to know for your flight from Porto to San Francisco

Information on your arrival and departure airports

Porto (OPO)
San Francisco (SFO)