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$342+ 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 4/13. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SFO
Feb 26 — Mar 51
Thu 2/26
Thu 3/5
1 adult, Economy
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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 January 27, 2026.

This Kiwi.com deal was found by Cheapflights users on 1/26. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/126:00 am
OPO
-
SFO
1 stop17h 55m
Lufthansa
Wed 2/251:30 pm
SFO
-
OPO
1 stop15h 45m
Lufthansa
Deal found 1/26$525
This Kiwi.com deal was found by Cheapflights users on 1/26. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/126:00 am
OPO
-
SFO
1 stop17h 55m
Multiple Airlines
Wed 2/257:25 pm
SFO
-
OPO
1 stop15h 10m
Multiple Airlines
Deal found 1/26$532
This United Airlines deal was found by Cheapflights users on 1/26. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/126:00 am
OPO
-
SFO
1 stop17h 55m
United Airlines
Tue 2/2412:43 am
SFO
-
OPO
2 stops24h 47m
United Airlines
Deal found 1/26$547
This Expedia deal was found by Cheapflights users on 1/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/1312:30 pm
OPO
-
SFO
1 stop15h 40m
Lufthansa
Sat 3/2110:40 pm
SFO
-
OPO
1 stop18h 00m
Lufthansa
Deal found 1/26$550
This Lufthansa deal was found by Cheapflights users on 1/27. 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 Lufthansa is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/126:00 am
OPO
-
SFO
1 stop17h 55m
Lufthansa
Mon 2/161:30 pm
SFO
-
OPO
1 stop15h 20m
Lufthansa
Deal found 1/27$551
This United Airlines deal was found by Cheapflights users on 1/25. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/126:00 am
OPO
-
SFO
2 stops22h 26m
United Airlines
Thu 3/195:05 am
SFO
-
OPO
2 stops21h 25m
United Airlines
Deal found 1/25$552
This KLM deal was found by Cheapflights users on 1/27. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/154:20 pm
OPO
-
SFO
1 stop27h 25m
KLM
Mon 5/188:10 pm
SFO
-
OPO
1 stop18h 20m
KLM
Deal found 1/27$553
This Delta deal was found by Cheapflights users on 1/27. 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 stops20h 50m
Delta
Mon 5/1811:05 am
SFO
-
OPO
2 stops20h 20m
Delta
Deal found 1/27$558
This Gotogate deal was found by Cheapflights users on 1/26. 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.
Thu 2/126:00 am
OPO
-
SFO
2 stops36h 54m
Air Canada
Wed 2/2512:00 pm
SFO
-
OPO
2 stops19h 25m
Air Canada
Deal found 1/26$564

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 January 27, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$525
(Kiwi.com)

One-way from

$342
(Kiwi.com)

Popular in

October

Cheapest in

January

Average price

$681
Provider with most accurate pricing for Porto-San Francisco flight deals.
Search Deals
Provider most trusted by Cheapflights users for Porto-San Francisco flights.
Search Deals
From Porto to San Francisco
Search Deals
One-way flight from Porto to San Francisco
Search Deals
High demand for flights, 2% potential price rise
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

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 January 27, 2026.
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

Thu 2/12

6:00 am-3:55 pm

1 stop17h 55m

San Francisco

Wed 2/25

1:30 pm-1:15 pm

1 stop15h 45m

$525

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 2/12

6:00 am-3:55 pm

1 stop17h 55m

San Francisco

Wed 2/25

7:00 am-9:30 am

1 stop18h 30m

$547

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Fri 3/13

12:30 pm-9:10 pm

1 stop15h 40m

San Francisco

Sat 3/21

10:40 pm-11:40 pm

1 stop18h 00m

$550

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 2/12

6:00 am-3:55 pm

1 stop17h 55m

San Francisco

Mon 2/16

1:30 pm-12:50 pm

1 stop15h 20m

$551

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 3/12

6:00 am-9:26 pm

2 stops22h 26m

San Francisco

Thu 3/19

5:05 am-9:30 am

2 stops21h 25m

$552

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Wed 4/15

6:00 am-3:25 pm

1 stop17h 25m

San Francisco

Sat 4/18

12:45 am-9:45 am

2 stops25h 00m

$552

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Fri 5/15

5:00 am-11:45 am

1 stop14h 45m

San Francisco

Mon 5/18

11:05 am-3:25 pm

2 stops20h 20m

$553

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Thu 2/12

6:00 am-10:54 am

2 stops36h 54m

San Francisco

Wed 2/25

12:00 pm-3:25 pm

2 stops19h 25m

$564

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Wed 2/11

2:35 pm-9:18 am

2 stops50h 43m

$374

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

Mon 4/13

6:00 pm-5:55 pm

2 stops31h 55m

$378

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/26

Showing 1-10 of 15 results
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, September is the cheapest month in which you can book a flight from Porto to San Francisco (average of $596). Flying from Porto to San Francisco in July is currently the most expensive (average of $817). 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 January 27, 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.
Lufthansa
6.8
Okay
7,748 reviews

Crew

7.6

Comfort

6.8

Food

6.3

Overall

6.8

Boarding

7.0

Entertainment

6.4

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
Lufthansa
6.8
Okay
7,748 reviews
Lufthansa
6.8
Okay
7,748 reviews

Crew

7.6

Comfort

6.8

Food

6.3

Overall

6.8

Boarding

7.0

Entertainment

6.4

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 Lufthansa and United Airlines fly from Porto to San Francisco in about 17h 55m. The time it takes to get you to your destination can typically vary by up to . There are 5566 mi between Porto and San Francisco.

  • 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 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 ($426), TAP AIR PORTUGAL ($516), and SWISS ($625).

  • 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, September is the cheapest month in which you can book a flight from Porto to San Francisco (average of $596). Flying from Porto to San Francisco in July is currently the most expensive (average of $817). 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
Roseville
Santa Clara
Livermore
Watsonville
San Bruno
Daly City
Sunnyvale
Turlock
Vacaville
San Carlos
San Ramon
Manteca
Vallejo
San Lorenzo
Davis
Hollister
Redwood City
Union City

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 January 27, 2026.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$670Average$844FlexibilityNo cancel feeOn-time76%

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