OPO - SFO

$357 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 9/9. 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

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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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, Sep 11 - Wed, Sep 24
TAP AIR PORTUGAL Logo
7:00 am - 2:30 pmOPO-SFO
15h 30m1 stop
TAP AIR PORTUGAL Logo
4:20 pm - 3:00 pmSFO-OPO
14h 40m1 stop
$598TAP AIR PORTUGAL
Find Deal
Thu, Sep 11 - Wed, Sep 24
TAP AIR PORTUGAL Logo
7:00 am - 2:30 pmOPO-SFO
15h 30m1 stop
TAP AIR PORTUGAL Logo
4:20 pm - 11:10 pmSFO-OPO
22h 50m1 stop
$601TAP AIR PORTUGAL
Find Deal
Tue, Oct 14 - Tue, Oct 28
SWISS Logo
8:40 am - 4:10 pmOPO-SFO
15h 30m1 stop
SWISS Logo
8:25 pm - 11:15 amSFO-OPO
31h 50m1 stop
$644SWISS
Find Deal
Tue, Oct 21 - Tue, Nov 4
 Logo
11:05 am - 7:00 pmOPO-SFO
15h 55m1 stop
 Logo
7:25 pm - 6:30 pmSFO-OPO
15h 05m1 stop
Tue, Oct 14 - Tue, Oct 28
SWISS Logo
8:40 am - 4:10 pmOPO-SFO
15h 30m1 stop
SWISS Logo
1:00 pm - 6:30 pmSFO-OPO
22h 30m2 stops
$655SWISS
Find Deal
Tue, Oct 21 - Tue, Nov 4
Air Canada Logo
6:15 am - 9:43 pmOPO-SFO
23h 28m2 stops
Air Canada Logo
8:38 am - 2:45 pmSFO-OPO
22h 07m2 stops
$701Air Canada
Find Deal
Thu, Sep 11 - Wed, Sep 24
 Logo
1:35 pm - 11:45 amOPO-SFO
30h 10m2 stops
 Logo
1:45 pm - 10:00 pmSFO-OPO
24h 15m2 stops
Wed, Oct 22 - Tue, Nov 4
United Airlines Logo
6:00 am - 7:55 pmOPO-SFO
21h 55m1 stop
United Airlines Logo
10:40 am - 9:30 amSFO-OPO
14h 50m1 stop
$710United Airlines
Find Deal
Tue, Oct 14 - Tue, Oct 28
Air Canada Logo
6:00 am - 9:40 pmOPO-SFO
23h 40m2 stops
Air Canada Logo
8:38 am - 2:45 pmSFO-OPO
23h 07m2 stops
$712Air Canada
Find Deal
Sat, Sep 27 - Sat, Oct 4
United Airlines Logo
6:00 am - 7:44 pmOPO-SFO
21h 44m2 stops
United Airlines Logo
5:15 am - 9:45 amSFO-OPO
20h 30m2 stops
$769United 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 November, where tickets cost $659 (return) on average. On the other hand, the most expensive months are October and June, where the average cost of round-trip tickets is $1,538 and $910 respectively.

Good to know

Low seasonMay
Cheapest flight$357
Best time to beat the crowds with an average 10% drop in price.
Most popular time to fly with an average 5% 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 $357 for a one-way ticket and $598 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.

  • 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 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 8915 reviews
7.3Comfort
7.7Boarding
7.1Entertainment
8.1Crew
6.6Food
Airline reviews

1. when we went to check in, our 2 first class seats had been CANCELED and the flight was sold out. This was done without our prior knowledge. It was all we could do to restore one first class seat for my wife and I flew economy. 2, Our flight home was scheduled to leave at 10:30 pm. Due to tsunami warnings, the roads were closed and our flight status was uncertain as to whether it would leave as scheduled. It was announced that it would now leave at 11:20 pm and the roads were now open since the tsunami had come and gone. We made a mad dash to the airport and checked in. Delays were announced at 12:30 pm, 1:30 am, 2:30 am and at 3:30 am it was canceled. Since this was a flight due to natural (tsunami) causes, there was no compensation. We were told to return at 1:00 pm the next day and our baggage would be kept on the plane since the same plane was going to leave at 1:00 pm. We had to return to our hotel for the rest of the night. The same plane did not leave at 1:00 pm and our baggage was gone! All in all, it was a miserable performance by UA. Information was hard to obtain and no one knew what was going on and what was going to happen. Hundreds of passengers slept on the floor, chairs, etc. No food and no water was made available to the passengers. It was a situation where UA could care less what was going on. As a one million mile flyer, I had not experienced anything like this before and it was hugely disappointing!

2.0 MediocreGeorge, Aug 2025HNL - SFO
Read more United Airlines reviews

1. when we went to check in, our 2 first class seats had been CANCELED and the flight was sold out. This was done without our prior knowledge. It was all we could do to restore one first class seat for my wife and I flew economy. 2, Our flight home was scheduled to leave at 10:30 pm. Due to tsunami warnings, the roads were closed and our flight status was uncertain as to whether it would leave as scheduled. It was announced that it would now leave at 11:20 pm and the roads were now open since the tsunami had come and gone. We made a mad dash to the airport and checked in. Delays were announced at 12:30 pm, 1:30 am, 2:30 am and at 3:30 am it was canceled. Since this was a flight due to natural (tsunami) causes, there was no compensation. We were told to return at 1:00 pm the next day and our baggage would be kept on the plane since the same plane was going to leave at 1:00 pm. We had to return to our hotel for the rest of the night. The same plane did not leave at 1:00 pm and our baggage was gone! All in all, it was a miserable performance by UA. Information was hard to obtain and no one knew what was going on and what was going to happen. Hundreds of passengers slept on the floor, chairs, etc. No food and no water was made available to the passengers. It was a situation where UA could care less what was going on. As a one million mile flyer, I had not experienced anything like this before and it was hugely disappointing!

I found the staff to not be very attentive at all. When paying for Business Class you expect a certain type of service and that was not found. They were almost rude even

Our experience on United Airlines was extremely poor. The plane was extremely cold throughout our entire flight- which multiple people complained about- and we had to wait 2 hours to get a blanket which was too thin and barely helped warm us up. As well as this, none of the entertainment features were working so we had to sit through a roughly 10 hour flight with nothing to keep our attention, including the actual flight path screen. It was an extremely disappointing experience and I would hope that this gets fixed if we ever choose United Airlines again.

I really enjoyed flying with United airlines amazing experience , good customer service and great food

1.It will be better if sandwich is warm. 2.The food is too salty. 3.Breakfast needs some vegetables or fruits.

Boarded plane and then delayed 1.5 hours while on the plane

It was all good flight was on time, service was good I enjoyed a few movies and everything was smooth

My flight was delayed a very short period of time but they did not hold my connecting flight to San Diego, also through United. So they closed the doors before we got off our plane. They would only have to help the door open for another five to ten minutes. So I missed a court deadline for a manditory mediation settlement conference for my client. I had to get an associate to be there in person and be on the phone with him relaying what he needs to do the entire time. The court was very upset with me and so was my client. United cannot be trusted.

Really good 😊 the woman at the gate entrance was a little rude checking in our carry-on but i dont think she worked for the airline, she worked for the airport at sacramento, other than that amazing.

Boarding was mayhem. Late boarding by 15 minutes because of lack of staff (missing 1 flight attendant. We had to wait for an arrival of another plane before we could board). Flight was a little rough, but cannot blame on airlines.

They don’t give information on why a flight is delayed in a timely manner. Very frustrating.

The flight was ok but chargers did not work and the speakers in the back of the cabin did not either. But I am writing because the crew was really, really rude and not only rude but had the curtains always closed, forgot to clear our trays, the bathrooms were filthy and trash was building out, and one of the attendants even had her EARBUDS on while in the cabin. From movement it seemed like she was listening to music, so not even the safety aspect was there. My neighbor s English is not good and they were very dismissive of her. when we deplaned the crew in the back was just chatting with one another and the first class attendant was briefly and said goodnight. It is nice that a crew gets along so well, but they did not take care of passengers at all. They rushed through all the services and otherwise did not go through the cabin to offer water or anything else. i had the feeling of being unwelcome at a party. I am not a grumpy traveller but I thought you really needed to know. Thank you, Carin

Food was terrible. They ran out of options and gave me a bland undercooked pasta and veggies. Only middle seat was available to select although I paid extra. Baggage delayed at destination. Flight attendants not really helpful.

Flight was late arriving. So, we left 25 min late. Pilot made some time up during the flight. Therefore, we arrived alittle past original time.

Crew was great. But my flight was late arriving and as a result, I missed my connecting flight to Richmond. I had to catch a later flight. On a positive note, the attendants at the counter were extremely helpful in booking my later flight. They book my on the next flight to Richmond.

If the plain wait for the passenger it should wait for the baggage!!

The plane (Mitsubishi CRJ) felt old, creaking and not very new. The crew was okay. Hot water provision was broken so hot beverages could't be served.

One one boarding scanner was working to scan 400+ passengers to an Airbus 380. Food in premium economy was mediocre.

Liked the flight being almost on time (airport issues created a delay). Disliked the issue printing tag bags on the kiosk and having to wait for an hour on like to drop my bags.

Our flight was delayed for over an hour due to weather, and it had already been a long travel day. However, the crew was calm and compassionate, listening to every complaint with genuine concern. They got us home safely without incident, in spite of all of the obstacles. I’m grateful.

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

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