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$351+ 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 5/20. Fares are subject to change and may not be available on all flights or dates of travel.
OPO — SFO
may. 5 — may. 121
lun. 5/5
lun. 5/12
1 adult, Economy
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Cheapflights Tip: The best prices from Porto to San Francisco are usually found in February or January, 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 abril 30, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$665
(Air France)

One-way from

$351
(Kiwi.com)

Popular in

October

Cheapest in

February

Average price

$833
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
Highest demand for flights based on searches. 12% potential increase in price ($129 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 7% potential price decrease ($61 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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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 abril 30, 2025.

This Air France 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 5/116:20 pmOPO - SFO
1 stop25h 25mMultiple Airlines
mar. 5/273:05 pmSFO - OPO
1 stop16h 25mMultiple Airlines
Deal found 4/29$665
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.
dom. 5/119:20 amOPO - SFO
1 stop16h 55mDelta
mar. 5/273:05 pmSFO - OPO
1 stop16h 25mDelta
Deal found 4/29$671
This British Airways 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 5/119:25 pmOPO - SFO
1 stop24h 25mBritish Airways
mar. 5/277:30 pmSFO - OPO
1 stop16h 00mBritish Airways
Deal found 4/29$697
This Air Canada 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 9/912:50 pmOPO - SFO
2 stops36h 17mAir Canada
sáb. 9/2011:50 amSFO - OPO
1 stop13h 45mAir Canada
Deal found 4/29$710
This United Airlines 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 9/711:20 amOPO - SFO
1 stop31h 51mUnited Airlines
sáb. 9/2011:50 amSFO - OPO
1 stop13h 45mUnited Airlines
Deal found 4/29$711
This Lufthansa 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 Lufthansa is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/86:15 amOPO - SFO
1 stop20h 45mLufthansa
vie. 9/199:05 pmSFO - OPO
1 stop18h 15mLufthansa
Deal found 4/29$753
This American Airlines 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 5/712:20 pmOPO - SFO
1 stop35h 50mAmerican Airlines
mié. 5/212:25 pmSFO - OPO
2 stops17h 30mAmerican Airlines
Deal found 4/29$768
This Austrian Airlines 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 Austrian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 9/91:30 pmOPO - SFO
2 stops37h 45mAustrian Airlines
vie. 9/197:55 pmSFO - OPO
2 stops37h 50mAustrian Airlines
Deal found 4/29$819
This AirNGo 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 AirNGo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 5/74:20 pmOPO - SFO
1 stop27h 25mKLM
mié. 5/218:25 pmSFO - OPO
1 stop28h 00mKLM
Deal found 4/29$898

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 abril 30, 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

dom. 5/11

6:20 pm-11:45 am

1 stop25h 25m

San Francisco

mar. 5/27

3:05 pm-3:30 pm

1 stop16h 25m

$665

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

dom. 5/11

9:20 am-6:15 pm

1 stop16h 55m

San Francisco

mar. 5/27

8:58 am-3:30 pm

2 stops22h 32m

$671

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

dom. 5/11

9:25 pm-1:50 pm

1 stop24h 25m

San Francisco

mar. 5/27

7:30 pm-7:30 pm

1 stop16h 00m

$697

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mar. 9/9

12:50 pm-5:07 pm

2 stops36h 17m

San Francisco

sáb. 9/20

11:50 am-9:35 am

1 stop13h 45m

$710

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

dom. 9/7

11:20 am-11:11 am

1 stop31h 51m

San Francisco

sáb. 9/20

11:50 am-9:35 am

1 stop13h 45m

$711

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

lun. 9/8

6:15 am-7:00 pm

1 stop20h 45m

San Francisco

vie. 9/19

9:05 pm-11:20 pm

1 stop18h 15m

$753

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

lun. 9/8

12:20 pm-12:16 am

2 stops19h 56m

San Francisco

vie. 9/19

2:28 pm-7:55 pm

2 stops21h 27m

$768

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

dom. 5/11

12:20 pm-12:22 am

2 stops20h 02m

San Francisco

mar. 5/27

2:17 pm-3:55 pm

2 stops17h 38m

$808

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mar. 9/9

1:30 pm-7:15 pm

2 stops37h 45m

San Francisco

vie. 9/19

7:55 pm-5:45 pm

2 stops37h 50m

$819

PortoSan Francisco

OPO - SFO

OPOSFO

Porto

mar. 5/20

5:10 pm-7:31 am

3 stops46h 21m

$351

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/29

Showing 1-10 of 21 results
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Compare providers for flights from Porto to San Francisco

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Porto to San Francisco in April.
ProviderPrice AccuracyTrust Score*
eDreamsPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Porto-San Francisco flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Porto-San Francisco flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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

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 April 25, 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 $393). 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.

What is the cheapest time of day to fly from OPO to SFO?

Find hourly flight availability from Porto to San Francisco. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated abril 30, 2025.

When flying from Porto to San Francisco, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Rainfall in San Francisco by month

Plan your trip to San Francisco by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in San Francisco ranges from 0.0 - 4.4 inches per month. January is typically the wettest month, when rainfall can reach 4.4 in. July is typically the driest time to visit San Francisco when rainfall is around 0.0 in.

Temperature in San Francisco by month

Plan your trip to San Francisco by taking into account the average temperature totals by month.

If weather is an important factor for your trip to San Francisco, use this chart to help with planning. For those seeking warmer temperatures, September is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 51.8 F).

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 abril 30, 2025.
Delta
8.0
Very good
7,936 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Delta
8.0
Very good
7,936 reviews
Delta
8.0
Very good
7,936 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Austrian Airlines
7.6
Good
780 reviews
Delta
8.0
Very good
7,936 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
SWISS
7.5
Good
1,588 reviews
Delta
8.0
Very good
7,936 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
United Airlines
7.4
Good
8,696 reviews
Delta
8.0
Very good
7,936 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Turkish Airlines
7.3
Good
3,788 reviews
Delta
8.0
Very good
7,936 reviews

Entertainment

7.9

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.3

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

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.

  • What are the cheapest airlines flying from Porto to San Francisco round-trip?

    Our cheapest airline available from Porto to San Francisco is Delta. Our recent data shows that you can find tickets from as low as $671 on this airline. Additional options worth looking into are British Airways and Air Canada, starting at $697 and $710 round-trip. These flights start at 22% 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 ($469), Vueling ($495), and TAP AIR PORTUGAL ($508).

  • 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 $393). 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 Porto?

Book flights to Porto if you plan to visit one of these locations
Roseville
Mountain View
Santa Cruz
Livermore
South San Francisco
Turlock
Manteca
Fairfield
Richmond
Watsonville
Hollister
Newark
Milpitas
Antioch
Sausalito
Hayward
Alameda
Sunnyvale
Campbell
Daly 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 abril 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$665Average$898FlexibilityNo cancel feeOn-time76%

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