OPO - SFO

$351 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 6/11. 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

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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Flights Deals

Cheap Flight Deals 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.

Recent round-trip flight deals from Porto to San Francisco

KAYAK's recommended round-trip deals from the most popular airlines that fly from Porto to San Francisco.
Discover the best prices for you by selecting your travel dates on KAYAK.
British Airways Logo
8:15 am - 9:27 amOPO-SFO
33h 12m2 stops
British Airways Logo
5:45 pm - 3:55 pmSFO-OPO
14h 10m1 stop
$704British Airways
Find Deal
Wed, Jun 25 - Tue, Jul 1
British Airways Logo
8:15 am - 11:43 pmOPO-SFO
23h 28m2 stops
British Airways Logo
5:45 pm - 3:55 pmSFO-OPO
14h 10m1 stop
$751British Airways
Find Deal
Wed, Jun 25 - Tue, Jul 1
American Airlines Logo
8:15 am - 8:30 pmOPO-SFO
20h 15m2 stops
American Airlines Logo
5:25 am - 7:35 amSFO-OPO
18h 10m2 stops
$810American Airlines
Find Deal
Wed, Jun 25 - Tue, Jul 1
American Airlines Logo
8:15 am - 11:14 amOPO-SFO
34h 59m2 stops
American Airlines Logo
6:00 am - 11:40 amSFO-OPO
21h 40m2 stops
$824American Airlines
Find Deal
Wed, Jun 25 - Tue, Jul 1
 Logo
8:40 am - 4:10 pmOPO-SFO
15h 30m1 stop
 Logo
9:05 pm - 11:20 pmSFO-OPO
18h 15m1 stop
Wed, Jun 25 - Tue, Jul 1
 Logo
6:15 am - 5:15 pmOPO-SFO
19h 00m2 stops
 Logo
8:30 pm - 10:35 pmSFO-OPO
18h 05m1 stop
Mon, May 19 - Mon, May 19
Air Canada Logo
12:10 pm - 10:33 amOPO-SFO
30h 23m2 stops
Air Canada Logo
8:36 am - 9:20 amSFO-OPO
16h 44m2 stops
$1,240Air Canada
Find Deal
Thu, Jul 17 - Wed, Aug 6
Air Canada Logo
12:10 pm - 10:33 amOPO-SFO
30h 23m2 stops
Air Canada Logo
10:56 pm - 9:20 amSFO-OPO
26h 24m2 stops
$1,247Air Canada
Find Deal
Thu, Jul 17 - Tue, Aug 5
Lufthansa Logo
6:15 am - 7:00 pmOPO-SFO
20h 45m1 stop
Lufthansa Logo
9:05 pm - 11:20 pmSFO-OPO
18h 15m1 stop
$1,522Lufthansa
Find Deal
Mon, May 19 - Mon, May 19
Lufthansa Logo
11:05 am - 7:00 pmOPO-SFO
15h 55m1 stop
Lufthansa Logo
9:05 pm - 11:20 pmSFO-OPO
18h 15m1 stop
$1,906Lufthansa
Find Deal
Fri, Jul 18 - Wed, Aug 6
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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 February, where tickets cost $673 (return) on average. On the other hand, the most expensive months are October and July, where the average cost of round-trip tickets is $1,538 and $1,023 respectively.

How far in advance should I book a flight from Porto to San Francisco?

To calculate weekly average prices, KAYAK takes all prices for each week before departure 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 average of all the values for each week.

To get a below average price on the flight from Porto to San Francisco, you should book around 1 week before departure. For the absolute cheapest price, our data suggests you should book 22 weeks before departure.

Good to know

Low seasonFebruary
High seasonDecember
Cheapest flight$351
Best time to beat the crowds with an average 23% drop in price.
Most popular time to fly with an average 3% 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 $351 for a one-way ticket and $704 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?

    oneworld, Star Alliance, and SkyTeam are the airline alliances operating flights between Porto and San Francisco, with Star Alliance being the most commonly used for this route.

  • Which is the best airline for flights from Porto to San Francisco, United Airlines or Lufthansa?

    The two airlines most popular with KAYAK users for flights from Porto to San Francisco are United Airlines and Lufthansa. With an average price for the route of $873 and an overall rating of 7.4, United Airlines is the most popular choice. Lufthansa is also a great choice for the route, with an average price of $898 and an overall rating of 6.7.

  • 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.

Top airlines 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.
7.4
United AirlinesOverall score based on 8702 reviews
7.1Entertainment
7.7Boarding
8.1Crew
7.3Comfort
6.6Food
Airline reviews

I needed to make changes to my flights. When I called customer service, they assisted me with care professionalism.

10.0 ExcellentMohammad Hassan Mirzai, May 2025HKG - SFO
Read more United Airlines reviews

I needed to make changes to my flights. When I called customer service, they assisted me with care professionalism.

A bit rush for transit. Food and entertainment are not available

The gate was too far away for the connecting flight

Generally good. The aisles have gotten narrower which can slow down boarding. Flight crew was great! Healthier complimentary snacks would be appreciated. Due to earthquake in San Francisco we had to circle in air space for a bit but then had a smooth landing. I laud the flight crew for their patience ;)

headphone jack didnt work for the first flight and not much variety

The agents was very rude and they charged me $50 for a carry-on bag saying that it was too big and then I saw someone going on a plane with the same size bag as me

For the most part united was a good experience, how ever when they came by with the snacks and water, they completely passed by my wife and I. As we were in separate rows. On a 5 hr flight we were not offered water

Fantastic crew. Flight was delayed at last minute but we were given updates every 20 minutes and the crew was so friendly and considerate. I miss the touch screens on the back of the seats, wish they would bring that back though.

Beijing PEK to SFO. I had an economy seat on this flight. The seat comfort was acceptable. My main complaint is with the FA’s lack of personality and absence from servicing the plane, specifically restroom care (I wish I could share a pic of the restroom that I captured) and care of travelers—drink cart/availability of drinks. I'm amazed at the level of service on other International travel where a passenger is most often appreciated.

Awful. Worst airline I have ever been on. Crew were among the rudest people I have ever dealt with. United staff members were rude and disrespectful. My flight was delayed, causing me to miss a connecting flight. I understand things happen, but when staff start lying about what actually happened, that is when I have an issue. Just be honest, really it isn’t that hard. I’m being very honest with this review and I don’t find this difficult what so ever. In fact, because of United Airlines, my Christmas holiday was off to a really rocky start. As someone who has traveled across the world, it has only been United that I have had a truly awful experience.

The plane was very clean. The bathroom was clean as well. The land crew were very polite and informative and helpful. They informed me that there is a long way and challenging to go from international terminal to national terminal and in addition to getting my suitcases and going through customs and dropping them again for my second leg of trip which was San Francisco to Los Angeles . I have left knee issue and had a recent fall with aching muscles all over, the land crew suggested wheelchair help for me, God bless her. If I did not have help, I could not make it to my last terminal. Thank you UNITED AIRLINE!

I like the service and the efficiency. I am lactose intolerant and the lactose intolerant meal in business class was not astounding. Also, the business class fully reclining seats are not that comfortable.

Food was great but they didn't clear my meal tray for 3 hours. You'd think they could check though the cabin now and then.

Upon arriving at IAH, it was informed that the luggage had not arrived. Still waiting to hear back when it will be delivered.

I wasn’t allowed to board with my children. I was charged outrageous costs for basic carry on size luggage. The entertainment screens were outdated and not user friendly.

I was very happy with everything, thank you for the smooth flight ✈️

helpful and friendly. The Lufthanza people I dealt with before my holiday were so unhelpful by comparison.

I enjoyed my flight back with Lufthansa because the food was good, and the flight attendants were nice and helped you when you asked a question. The flight attendants always came around and asked if you needed anything which I liked a lot.

Entertainment system is old. Food can be tastier Need to provide toothbrush and toothpaste at least when asked.

The flight was cancelled due to tech problem with the plane

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

Information on your arrival and departure airports

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