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$142+ Cheap flights from Islip to San Francisco (ISP - 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 11/19. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — SFO
oct. 9 — oct. 161
jue. 10/9
jue. 10/16
1 adult, Economy
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Cheap flight deals from Islip to San Francisco

Discover tips and strategies to find the most affordable flight options for your journey from Islip (ISP) 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 9, 2025.

Round-trip from

$248
(Frontier)

One-way from

$142
(Kiwi.com)

Popular in

December

Cheapest in

February

Average price

$387
From Islip Long Island to San Francisco
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One-way flight from Islip Long Island to San Francisco
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Highest demand for flights based on searches. 7% potential increase in price ($33 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Islip to San Francisco

Cheapest flights from Islip to San Francisco
Explore the most affordable flight options available from Islip to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on septiembre 9, 2025.

This Frontier deal was found by Cheapflights users on 9/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 9/275:05 pmISP - SFO
2 stops18h 10mFrontier
lun. 10/611:57 pmSFO - ISP
2 stops17h 45mFrontier
Deal found 9/7$248
This Frontier deal was found by Cheapflights users on 9/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 9/275:05 pmISP - SFO
2 stops18h 10mFrontier
jue. 10/27:07 pmSFO - ISP
2 stops12h 33mFrontier
Deal found 9/7$252
This Gotogate deal was found by Cheapflights users on 9/8. 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.
jue. 10/239:37 pmISP - SFO
2 stops21h 23mFrontier
jue. 10/304:06 pmSFO - ISP
2 stops39h 31mFrontier
Deal found 9/8$256
This Frontier deal was found by Cheapflights users on 9/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 9/275:05 pmISP - SFO
2 stops18h 10mFrontier
vie. 10/37:07 pmSFO - ISP
2 stops12h 48mFrontier
Deal found 9/7$293
This Frontier deal was found by Cheapflights users on 9/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 9/275:05 pmISP - SFO
2 stops18h 10mFrontier
dom. 10/57:07 pmSFO - ISP
2 stops12h 33mFrontier
Deal found 9/7$295
This Booking.com deal was found by Cheapflights users on 9/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/84:58 pmISP - SFO
2 stops50h 02mFrontier
mar. 10/146:34 amSFO - ISP
2 stops25h 23mFrontier
Deal found 9/8$309
This Frontier deal was found by Cheapflights users on 9/8. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 10/269:47 pmISP - SFO
2 stops21h 13mFrontier
dom. 11/910:23 pmSFO - ISP
2 stops17h 43mFrontier
Deal found 9/8$317
This Frontier deal was found by Cheapflights users on 9/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 9/289:49 amISP - SFO
2 stops17h 27mFrontier
jue. 10/211:57 pmSFO - ISP
2 stops13h 30mFrontier
Deal found 9/7$337
This Frontier deal was found by Cheapflights users on 9/7. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 9/289:49 amISP - SFO
2 stops17h 27mFrontier
lun. 10/67:07 pmSFO - ISP
2 stops16h 06mFrontier
Deal found 9/7$338
This Booking.com deal was found by Cheapflights users on 9/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 9/2311:25 amISP - SFO
2 stops38h 05mFrontier
sáb. 9/2710:49 amSFO - ISP
2 stops19h 15mFrontier
Deal found 9/8$339
This Booking.com deal was found by Cheapflights users on 9/8. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 10/211:40 amISP - SFO
2 stops36h 41mFrontier
jue. 10/95:45 amSFO - ISP
2 stops25h 52mFrontier
Deal found 9/8$346
This Frontier deal was found by Cheapflights users on 9/8. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 9/135:05 pmISP - SFO
2 stops18h 10mFrontier
lun. 9/227:07 pmSFO - ISP
2 stops12h 33mFrontier
Deal found 9/8$375

Cheapflights Fare Finder

 
Customize your flight search to find flights from Islip 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 9, 2025.
Use the filters below to find and compare flights from Islip to San Francisco that are best for you.

Fly from

Islip

Fly to

San Francisco

Route

Depart

Return

Price

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

jue. 10/23

9:37 pm-4:00 pm

2 stops21h 23m

San Francisco

jue. 10/30

4:06 pm-10:37 am

2 stops39h 31m

$256

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

sáb. 9/27

5:05 pm-8:15 am

2 stops18h 10m

San Francisco

dom. 10/5

7:07 pm-10:40 am

2 stops12h 33m

$295

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

mié. 10/8

4:58 pm-4:00 pm

2 stops50h 02m

San Francisco

mar. 10/14

6:34 am-10:57 am

2 stops25h 23m

$309

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

dom. 9/28

9:49 am-12:16 am

2 stops17h 27m

San Francisco

lun. 10/6

7:07 pm-2:13 pm

2 stops16h 06m

$338

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

mar. 9/23

11:25 am-10:30 pm

2 stops38h 05m

San Francisco

sáb. 9/27

10:49 am-9:04 am

2 stops19h 15m

$339

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

jue. 10/2

11:40 am-9:21 pm

2 stops36h 41m

San Francisco

jue. 10/9

5:45 am-10:37 am

2 stops25h 52m

$346

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

jue. 10/23

9:37 pm-10:53 pm

1 stop28h 16m

San Francisco

jue. 10/30

8:25 am-10:37 am

1 stop23h 12m

$407

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

sáb. 9/20

5:05 pm-8:15 am

2 stops18h 10m

San Francisco

vie. 9/26

7:07 pm-10:55 am

2 stops12h 48m

$413

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

sáb. 9/20

5:05 pm-8:15 am

2 stops18h 10m

San Francisco

sáb. 9/27

2:10 pm-10:40 am

2 stops17h 30m

$424

IslipSan Francisco

ISP - SFO

ISPSFO

Islip Long Island

sáb. 9/20

5:05 pm-8:15 am

2 stops18h 10m

San Francisco

jue. 9/25

5:05 pm-10:40 am

2 stops14h 35m

$440

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/7

Showing 1-10 of 22 results
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Best time to book a flight from Islip to San Francisco

Have a flexible travel schedule? Discover the best time to fly to San Francisco from Islip 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 Islip to San Francisco

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

Currently, January is the cheapest month in which you can book a flight from Islip to San Francisco (average of $276). Flying from Islip 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.

Related info for your journey

Find useful and relevant information for your journey from Islip 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 Islip to San Francisco?

    Frontier can get you from Islip to San Francisco in just under 21h 23m. Your travel time can differ by up to . There are 2611 mi between Islip and San Francisco.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Islip 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 Islip to San Francisco?

    Currently, January is the cheapest month in which you can book a flight from Islip to San Francisco (average of $276). Flying from Islip 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

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