HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
San Francisco

$368+ Cheap flights from Porto (OPO) to San Francisco (SFO)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/14. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SFO
oct. 11 — oct. 181
sáb. 10/11
sáb. 10/18
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Porto to San Francisco with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Porto to San Francisco are usually found in November or February, booked 44 days in advance, depart on a Wednesday or Thursday and return on a Thursday

Cheap flight deals from Porto to San Francisco

Discover tips and strategies to find the most affordable flight options for your journey from Porto (OPO) to San Francisco (SFO). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated septiembre 11, 2025.

Round-trip from

$564
(Scandinavian Airlines)

One-way from

$368
(Kiwi.com)

Popular in

October

Cheapest in

November

Average price

$709
From Porto to San Francisco
Search Deals
One-way flight from Porto to San Francisco
Search Deals
Highest demand for flights based on searches. 13% potential increase in price ($126 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 8% potential price decrease ($64 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

Find flight deals from Porto to San Francisco

Cheapest flights from Porto to San Francisco
Explore the most affordable flight options available from Porto to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on septiembre 11, 2025.

This Scandinavian Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 12/55:45 pmOPO - SFO
1 stop28h 50mScandinavian Airlines
jue. 12/114:40 pmSFO - OPO
1 stop16h 15mScandinavian Airlines
Deal found 9/10$564
This lol.travel deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure lol.travel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 9/117:00 amOPO - SFO
1 stop15h 30mTAP AIR PORTUGAL
mié. 9/244:20 pmSFO - OPO
1 stop14h 40mTAP AIR PORTUGAL
Deal found 9/9$597
This Trip.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 11/145:35 pmOPO - SFO
1 stop29h 00mScandinavian Airlines
dom. 11/234:40 pmSFO - OPO
1 stop16h 05mScandinavian Airlines
Deal found 9/11$616
This lastminute.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure lastminute.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 9/1210:35 pmOPO - SFO
1 stop27h 00mTAP AIR PORTUGAL
sáb. 9/277:20 pmSFO - OPO
1 stop13h 40mTAP AIR PORTUGAL
Deal found 9/11$649
This AirNGo deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure AirNGo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 9/1410:30 pmOPO - SFO
1 stop24h 00mTAP AIR PORTUGAL
mar. 9/234:20 pmSFO - OPO
1 stop31h 35mTAP AIR PORTUGAL
Deal found 9/9$655
This Iberia deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 12/58:40 pmOPO - SFO
2 stops20h 41mIberia
jue. 12/117:25 amSFO - OPO
2 stops16h 15mIberia
Deal found 9/10$662
This Air France deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 10/66:30 amOPO - SFO
1 stop37h 15mMultiple Airlines
dom. 10/193:05 pmSFO - OPO
1 stop16h 25mMultiple Airlines
Deal found 9/11$665

Cheapflights Fare Finder

 
Customize your flight search to find flights from Porto to San Francisco that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 11, 2025.
Use the filters below to find and compare flights from Porto to San Francisco that are best for you.

Fly from

Porto

Fly to

San Francisco

Route

Depart

Return

Price

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

vie. 12/5

5:45 pm-2:35 pm

1 stop28h 50m

San Francisco

jue. 12/11

4:40 pm-4:55 pm

1 stop16h 15m

$564

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mié. 10/8

10:15 pm-2:30 pm

2 stops24h 15m

San Francisco

mié. 10/15

4:20 pm-10:05 pm

2 stops21h 45m

$658

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

dom. 3/1

11:15 am-11:50 am

1 stop32h 35m

San Francisco

mar. 3/31

3:05 pm-3:30 pm

1 stop16h 25m

$667

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

sáb. 11/15

6:00 am-10:41 pm

2 stops24h 41m

San Francisco

lun. 11/24

6:00 am-10:15 am

2 stops20h 15m

$671

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

vie. 12/5

4:10 pm-11:50 am

1 stop27h 40m

San Francisco

jue. 12/11

1:55 pm-3:25 pm

1 stop17h 30m

$671

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mié. 9/24

6:15 am-7:48 pm

2 stops21h 33m

San Francisco

mié. 10/8

10:40 am-3:30 pm

2 stops20h 50m

$671

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mié. 9/24

6:15 am-5:47 pm

2 stops19h 32m

San Francisco

mié. 10/8

3:05 pm-3:30 pm

1 stop16h 25m

$672

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mié. 10/8

6:15 am-11:33 pm

2 stops25h 18m

San Francisco

mié. 10/15

3:05 pm-3:30 pm

1 stop16h 25m

$673

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mar. 10/14

8:10 pm-2:35 pm

2 stops26h 25m

$368

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

lun. 1/12

8:45 am-9:16 pm

2 stops44h 31m

$379

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/9

Showing 1-10 of 15 results
1
2

Best time to book a flight from Porto to San Francisco

Have a flexible travel schedule? Discover the best time to fly to San Francisco from Porto with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

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

Use this chart to determine the optimal time to book a round-trip flight from Porto to San Francisco. Price data was last updated on August 29, 2025.

The price you pay for your flight from Porto to San Francisco may vary depending on when you book. For the best chance of a lower fare, look to book 44 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Porto to San Francisco?

Currently, January is the cheapest month in which you can book a flight from Porto to San Francisco (average of $276). Flying from Porto to San Francisco in June is currently the most expensive (average of $357). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost to fly round-trip from Porto to San Francisco?

Reviews of airlines servicing San Francisco

Get insights into the airlines that provide service to San Francisco. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to San Francisco. Reviews last updated septiembre 11, 2025.
Peruse reviews from past customers who have flown with Lufthansa from Porto to San Francisco to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Lufthansa
6.8
Okay
7,409 reviews

Crew

7.6

Food

6.3

Overall

6.8

Boarding

7.0

Comfort

6.8

Entertainment

6.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Jan 2025

FRA - TPA

I had ordered a gluten-free meal through you I double triple checked that through you got screamed at by one of your representatives. She yelled at me and said that she had ordered the mail, she had chosen my seat, and made sure that all my baggage is were paid for. That was a lie. My experience with discover airlines in and of itself was GOOD but your representative was out of line did not do anything that she screamed at me and told me she did and I literally had to call the airlines myself to get my seat selected to double check on my gluten-free meal which still was not on board and to pay for my bags which I thought that I paid for all of them until I got to the airport and I still had to pay for my check back. So cheap flights I will never use you again.
Lufthansa
6.8
Okay
7,409 reviews
Lufthansa
6.8
Okay
7,409 reviews

Crew

7.6

Food

6.3

Overall

6.8

Boarding

7.0

Comfort

6.8

Entertainment

6.4

Reviews

1 / 20
8.0
Excellent

Anonymous,Jan 2025

FRA - TPA

I had ordered a gluten-free meal through you I double triple checked that through you got screamed at by one of your representatives. She yelled at me and said that she had ordered the mail, she had chosen my seat, and made sure that all my baggage is were paid for. That was a lie. My experience with discover airlines in and of itself was GOOD but your representative was out of line did not do anything that she screamed at me and told me she did and I literally had to call the airlines myself to get my seat selected to double check on my gluten-free meal which still was not on board and to pay for my bags which I thought that I paid for all of them until I got to the airport and I still had to pay for my check back. So cheap flights I will never use you again.

Related info for your journey

Find useful and relevant information for your journey from Porto to San Francisco. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • How long is the flight from Porto to San Francisco?

    Airlines like Scandinavian Airlines, KLM, and Delta fly from Porto to San Francisco in about 24h 41m. The time it takes to get you to your destination can typically vary by up to 7h 54m. There are 5566 mi between Porto and San Francisco. This flight may include one or multiple stops.

  • What is the cheapest airline to fly from Porto to San Francisco round-trip?

    Our cheapest airline available from Porto to San Francisco is Lufthansa. Our recent data shows that you can find tickets from as low as $670 on this airline. This flight start at 20% lower than the current average price 3 months from now.

  • Can I find deals for flights from Porto to San Francisco that include hotel bookings?

    Yes. In addition to deals on Porto to San Francisco flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Porto to San Francisco?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Porto to San Francisco.

  • Can I find deals for business class flights from Porto to San Francisco?

    Yes. Cheapflights offers flight deals from Porto to San Francisco by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, January is the cheapest month in which you can book a flight from Porto to San Francisco (average of $276). Flying from Porto to San Francisco in June is currently the most expensive (average of $357). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near San Francisco?

Book flights to San Francisco if you plan to visit one of these locations
Roseville
Santa Cruz
Livermore
South San Francisco
Turlock
Antioch
Watsonville
Manteca
Santa Clara
Sunnyvale
Hollister
Vacaville
Foster City
Vallejo
Burlingame
Redwood City
Union City
San Leandro
San Mateo
Lathrop

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top airline flying from Porto to San Francisco

Discover the top airline that operate flights from Porto to San Francisco. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$670Average$847FlexibilityNo cancel feeOn-time76%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.