$170+ Cheap flights from Islip, NY to Ontario (ISP - ONT)
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 9/7. Fares are subject to change and may not be available on all flights or dates of travel.
ISP — ONT
Jul 8 — Jul 151
1 adult, Economy
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Find cheap flights from Islip to Ontario 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
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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 Islip to Ontario
Discover tips and strategies to find the most affordable flight options for your journey from Islip (ISP) to Ontario (ONT). 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 July 3, 2025.
Round-trip from | $585 (FlightHub) |
|---|---|
One-way from | $170 (Cheapflightsfares) |
Popular in | December |
Cheapest in | September |
Average price | $396 |
Find flight deals from Islip to Ontario
Cheapest flights from Islip to OntarioExplore the most affordable flight options available from Islip to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 3, 2025.
Explore the most affordable flight options available from Islip to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 3, 2025.
This FlightHub deal was found by Cheapflights users on 7/2. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 7/206:00 amISP - ONT
2 stops30h 13mFrontier
Sat 7/268:09 pmONT - ISP
2 stops24h 38mFrontier
Deal found 7/2![Frontier logo]()
$585
This United deal was found by Cheapflights users on 7/3. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/111:53 amISP - ONT
2 stops13h 38mMultiple Airlines
Wed 11/51:00 pmONT - ISP
2 stops18h 58mMultiple Airlines
Deal found 7/3![Multiple Airlines logo]()
$891
Cheapflights Fare Finder
Customize your flight search to find flights from Islip to Ontario 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 July 3, 2025.
Use the filters below to find and compare flights from Islip to Ontario that are best for you.
Fly from
Islip
Fly to
Ontario
Route
Depart
Return
Price
IslipOntario
ISP - ONT
ISPONT
Islip Long Island
Sun 7/20
6:00 am-9:13 am
2 stops30h 13m
Ontario
Sat 7/26
8:09 pm-11:47 pm
2 stops24h 38m
$585
IslipOntario
ISP - ONT
ISPONT
Islip Long Island
Sat 11/1
11:53 am-10:31 pm
2 stops13h 38m
Ontario
Wed 11/5
1:00 pm-10:58 am
2 stops18h 58m
$891
IslipOntario
ISP - ONT
ISPONT
Islip Long Island
Sun 9/7
9:49 am-6:35 pm
2 stops11h 46m
$170
IslipOntario
ISP - ONT
ISPONT
Islip Long Island
Thu 7/10
11:53 am-8:54 pm
2 stops12h 01m
$579
Best time to book a flight from Islip to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario 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 Ontario
What is the cheapest month to book a flight from Islip, New York to Ontario?
Currently, August is the cheapest month in which you can book a flight from Islip, New York to Ontario (average of $246). Flying from Islip, New York to Ontario in March is currently the most expensive (average of $328). 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 Ontario
Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated July 3, 2025.
Peruse reviews from past customers who have flown with Frontier from Islip to Ontario 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.
Overall
5.9
Comfort
5.6
Food
4.7
Crew
6.8
Boarding
6.2
Entertainment
4.5
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2025
TTN - TPA
Overall
5.9
Comfort
5.6
Food
4.7
Crew
6.8
Boarding
6.2
Entertainment
4.5
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2025
TTN - TPA