San Francisco

$419+ 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 5/14. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SFO
May 29 — Jun 51
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.

Cheap 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 April 29, 2026.

This ResecentrumGruppen deal was found by Cheapflights users on 4/24. 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 ResecentrumGruppen is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/15:00 am
OPO
-
SFO
1 stop14h 45m
KLM
Thu 5/143:05 pm
SFO
-
OPO
1 stop22h 55m
KLM
Deal found 4/24$750
This Flysmarter deal was found by Cheapflights users on 4/29. 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 Flysmarter is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/811:25 am
OPO
-
SFO
1 stop32h 20m
KLM
Thu 5/143:05 pm
SFO
-
OPO
1 stop22h 55m
KLM
Deal found 4/29$796
This KLM deal was found by Cheapflights users on 4/29. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/1111:25 am
OPO
-
SFO
1 stop32h 20m
KLM
Wed 5/278:10 pm
SFO
-
OPO
1 stop17h 50m
KLM
Deal found 4/29$797
This KLM deal was found by Cheapflights users on 4/28. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/155:00 am
OPO
-
SFO
1 stop14h 45m
KLM
Mon 5/188:10 pm
SFO
-
OPO
1 stop17h 50m
KLM
Deal found 4/28$798
This Air France deal was found by Cheapflights users on 4/28. 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.
Thu 5/1411:25 am
OPO
-
SFO
1 stop32h 20m
Multiple Airlines
Wed 5/278:10 pm
SFO
-
OPO
1 stop17h 50m
Multiple Airlines
Deal found 4/28$799
This Delta deal was found by Cheapflights users on 4/24. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/15:00 am
OPO
-
SFO
2 stops22h 20m
Delta
Thu 5/148:10 pm
SFO
-
OPO
1 stop17h 50m
Delta
Deal found 4/24$802
This Delta deal was found by Cheapflights users on 4/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/115:00 am
OPO
-
SFO
1 stop14h 45m
Delta
Wed 5/274:55 pm
SFO
-
OPO
2 stops21h 20m
Delta
Deal found 4/29$803
This Delta deal was found by Cheapflights users on 4/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/145:00 am
OPO
-
SFO
1 stop14h 45m
Delta
Thu 5/289:43 am
SFO
-
OPO
2 stops21h 47m
Delta
Deal found 4/28$804
This Delta deal was found by Cheapflights users on 4/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/145:00 am
OPO
-
SFO
2 stops18h 58m
Delta
Wed 5/274:55 pm
SFO
-
OPO
2 stops21h 20m
Delta
Deal found 4/28$809
This Delta deal was found by Cheapflights users on 4/27. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/155:00 am
OPO
-
SFO
2 stops22h 20m
Delta
Mon 5/183:05 pm
SFO
-
OPO
1 stop22h 55m
Delta
Deal found 4/27$833
This Gotogate deal was found by Cheapflights users on 4/24. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/126:00 am
OPO
-
SFO
1 stop17h 25m
Lufthansa
Tue 5/199:05 pm
SFO
-
OPO
1 stop18h 20m
Lufthansa
Deal found 4/24$845

Find 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 April 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$797
(KLM)

One-way from

$419
(Kiwi.com)

Popular in

May

Cheapest in

January

Average price

$738
Provider with most accurate pricing for Porto-San Francisco flight deals.
Provider most trusted by Cheapflights users for Porto-San Francisco flights.
From Porto to San Francisco
One-way flight from Porto to San Francisco
Highest demand for flights based on searches. 8% potential increase in price ($75 potential increase over avg. RT price).
Cheapest flight prices on average. 2% potential price decrease ($20 potential savings vs. average RT price).
Average for round-trip flights in April 2026

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 April 29, 2026.
Use the filters below to find and compare flights from Porto to San Francisco that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Sat 5/16

5:00 am-5:49 pm

2 stops20h 49m

San Francisco

Mon 6/1

11:00 pm-10:00 pm

1 stop15h 00m

$803

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Tue 5/26

5:00 am-7:20 pm

2 stops22h 20m

San Francisco

Tue 6/2

8:10 pm-10:05 pm

1 stop17h 55m

$804

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Sun 5/24

6:00 am-3:15 pm

1 stop17h 15m

San Francisco

Sun 5/31

7:00 am-9:45 am

1 stop18h 45m

$849

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Wed 9/23

5:00 am-11:45 am

1 stop14h 45m

San Francisco

Wed 10/7

11:30 am-3:25 pm

2 stops19h 55m

$856
Quickest round-trip

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Fri 5/15

5:00 am-11:45 am

1 stop14h 45m

San Francisco

Mon 5/18

8:10 pm-10:00 pm

1 stop17h 50m

$859

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 6/11

7:10 pm-11:45 am

1 stop24h 35m

San Francisco

Sat 7/4

8:10 pm-10:00 pm

1 stop17h 50m

$861

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Fri 10/2

5:55 am-6:00 pm

1 stop20h 05m

San Francisco

Tue 10/6

3:05 pm-3:25 pm

1 stop16h 20m

$861

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 6/11

5:00 am-6:30 pm

2 stops21h 30m

San Francisco

Sat 7/4

8:10 pm-10:00 pm

1 stop17h 50m

$868
Cheapest one-way

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 10/15

7:00 am-9:55 pm

3 stops22h 55m

$547

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Sat 10/3

12:25 pm-8:55 am

2 stops28h 30m

$549

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/24

Showing 1-10 of 19 resultsSorted by cheapest first
1
2
  • Most accurate provider: When it comes to deals on Porto-San Francisco flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Porto-San Francisco flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Porto-San Francisco flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Porto-San Francisco flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Porto-San Francisco flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

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 $692). Flying from Porto to San Francisco in May is currently the most expensive (average of $1,031). 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.

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 April 29, 2026.
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.

Comfort

6.8

Crew

7.6

Food

6.3

Boarding

7.0

Entertainment

6.4

Overall

6.8

Reviews

1 / 20
4.0
Okay

Djermouli,Dec 2025

FRA - SFO

I’m sorry the worst airline united food sales I’m diabetic plus high cholesterol pls seats it’s not comfortable plus screen tv broke I try to charge my phone don’t work I’m not flying with united airlines

Comfort

6.8

Crew

7.6

Food

6.3

Boarding

7.0

Entertainment

6.4

Overall

6.8

Reviews

1 / 20
4.0
Okay

Djermouli,Dec 2025

FRA - SFO

I’m sorry the worst airline united food sales I’m diabetic plus high cholesterol pls seats it’s not comfortable plus screen tv broke I try to charge my phone don’t work I’m not flying with united airlines

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 Delta, Lufthansa, and KLM fly from Porto to San Francisco in about 14h 45m. The time it takes to get you to your destination can typically vary by up to 6h 04m. 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 $688 on this airline. This flight start at 15% lower than the current average price 3 months from now.

  • What are the cheapest airlines to fly from Porto to San Francisco one-way?

    The cheapest airlines for a one-way flight from Porto to San Francisco are Iberia ($449), TAP AIR PORTUGAL ($526), and SWISS ($624).

  • 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 $692). Flying from Porto to San Francisco in May is currently the most expensive (average of $1,031). 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
South San Francisco
Santa Cruz
Santa Clara
Fairfield
Rancho Cordova
San Bruno
Watsonville
San Ramon
Emeryville
Vacaville
Roseville
San Carlos
Redwood City
Sunnyvale
Turlock
San Lorenzo
Davis
Manteca
Union City
Elk Grove

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 April 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$688Average$844FlexibilityNo 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.