OPO - SFO

$404 Find Cheap Flights from Porto to San Francisco - Compare and Save

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 9/24. 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

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Everything you should know

Cheapest round-trip
$634
Typical prices: $690-$887
Air Canada, Lufthansa
Tue 12/22Fri 1/1
OPO - SFO • 2 stops
Cheapest one-way
$404
Typical prices: $579-$944
Multiple Airlines
Thu 9/24
OPO - SFO • 3 stops
Top airlines
Cheapest • from $637 (round-trip)
Best reviews • 6.8 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Porto and San Francisco. You'll need at least 1 connection.
Insights
Insights
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Insights
Top layover airports
Cheapest • Avg $731 (round-trip)
Shortest trip • 15h 27m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 17% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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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

Tue, Dec 22 - Fri, Jan 1
Multiple Airlines Logo
6:00 am - 9:30 pm
OPO
-
SFO
47h 30m
2 stops
Multiple Airlines Logo
9:40 pm - 11:55 pm
SFO
-
OPO
18h 15m
1 stop
$634Multiple Airlines
Tue, Dec 22 - Fri, Jan 1
Multiple Airlines Logo
6:00 am - 9:30 pm
OPO
-
SFO
47h 30m
2 stops
Multiple Airlines Logo
2:45 pm - 3:20 pm
SFO
-
OPO
16h 35m
1 stop
$635Multiple Airlines
Thu, Sep 17 - Sun, Sep 20
SWISS Logo
8:40 am - 4:15 pm
OPO
-
SFO
15h 35m
1 stop
SWISS Logo
7:35 pm - 6:15 pm
SFO
-
OPO
14h 40m
1 stop
$637SWISS
Mon, Aug 24 - Sun, Sep 6
Multiple Airlines Logo
6:00 am - 3:15 pm
OPO
-
SFO
17h 15m
1 stop
Multiple Airlines Logo
2:20 pm - 6:15 pm
SFO
-
OPO
19h 55m
1 stop
$640Multiple Airlines
Thu, Sep 3 - Fri, Sep 18
Lufthansa Logo
6:20 am - 7:00 pm
OPO
-
SFO
20h 40m
1 stop
Lufthansa Logo
9:05 pm - 11:25 pm
SFO
-
OPO
18h 20m
1 stop
$641Lufthansa
Tue, Dec 22 - Fri, Jan 1
Air Canada Logo
6:00 am - 9:30 pm
OPO
-
SFO
47h 30m
2 stops
Air Canada Logo
8:40 am - 3:20 pm
SFO
-
OPO
22h 40m
2 stops
$642Air Canada
Mon, Aug 24 - Sun, Sep 6
United Airlines Logo
6:00 am - 3:15 pm
OPO
-
SFO
17h 15m
1 stop
United Airlines Logo
11:59 pm - 6:55 am
SFO
-
OPO
22h 56m
1 stop
$643United Airlines
Mon, Aug 24 - Sun, Aug 30
United Airlines Logo
6:00 am - 3:15 pm
OPO
-
SFO
17h 15m
1 stop
United Airlines Logo
12:45 am - 9:45 am
SFO
-
OPO
25h 00m
2 stops
$644United Airlines
Wed, Sep 23 - Wed, Oct 7
United Airlines Logo
6:00 am - 7:50 pm
OPO
-
SFO
21h 50m
1 stop
United Airlines Logo
8:10 am - 7:00 am
SFO
-
OPO
14h 50m
1 stop
$646United Airlines
Thu, Sep 10 - Sat, Sep 26
United Airlines Logo
6:00 am - 3:20 pm
OPO
-
SFO
17h 20m
1 stop
United Airlines Logo
5:00 am - 7:00 am
SFO
-
OPO
18h 00m
2 stops
$647United Airlines
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.

How much is a round-trip flight from Porto to San Francisco?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Porto to San Francisco departing in December.

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 January, where tickets cost $704 (return) on average. On the other hand, the most expensive months are June and May, where the average cost of round-trip tickets is $1,154 and $1,031 respectively.

Good to know

Low seasonMay
Cheapest flight$404
Best time to beat the crowds but there is an average 21% increase in price.
Most popular time to fly with an average 7% 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 5 days, the lowest price for a flight from Porto to San Francisco was $404 for a one-way ticket and $634 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 8131 reviews
6.4Entertainment
6.3Food
7.0Boarding
6.8Comfort
7.6Crew
Airline reviews

Generally good. Not their fault but the design of the Boeing 747 had seating supports directly in line with my legs. So my legs always had to straddle this support which caused body misallignment. Such poor design from Boeing. There was no USB port for me to charge my phone. The screen touch control was very poor.

10.0 ExcellentAnonymous, Mar 2026
FRA - SFO
Read more Lufthansa reviews

Generally good. Not their fault but the design of the Boeing 747 had seating supports directly in line with my legs. So my legs always had to straddle this support which caused body misallignment. Such poor design from Boeing. There was no USB port for me to charge my phone. The screen touch control was very poor.

Best flight attendants ever! Very customer and service oriented, courteous, professional and helpful.

Never happened. Flight was delayed. Had to be re rojyed

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 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.

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

This was the best carrier, comfort, service, good food, on time experience on a long haul flight. New, clean, quiet, smooth aircraft!!!

The plane was clean and the staff courteous and professional. The seat bottom was uncomfortable but only after many hours. It had a pressure point that left me a small bruise on my right leg (very surprising). The pasta was terrible (hard on the edges sticking out and soggy on the bottom edges) but I guess that's how it comes out in a microwave (?). The entertainment was glitching and shutting off every 20 minutes or so but, in the end, we made it home safely with very little turbulence and that's what really matters.

Would never fly lauffthabsa again. Seats were way too crowded together....very uncomfortable le

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

Information on your arrival and departure airports