$117 Cheap Flights from Trenton (TTN) to Islip (ISP)

View $117 flight on Thu, Aug 21, 2025Opens in a new window

Popular airlines from Trenton–Mercer Airport (TTN) to MacArthur Airport (ISP)

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Cheap Flights from Trenton to Islip (TTN-ISP)

Prices were available within the past 7 days and start at $117 for one-way flights and $583 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Thu, Nov 6 - Sun, Nov 9
TTN
Trenton
ISP
Islip
$583 Roundtrip, found 9 hours ago
$583
Roundtrip
found 9 hours ago
Select Frontier Airlines flight, departing Thu, Nov 6 from Trenton to Islip, returning Sun, Nov 9, priced at $583 found 9 hours ago
Flights from Trenton (TTN) to Islip (ISP)
Origin airport
Mercer
Destination airport
MacArthur
Airlines serving
Frontier Airlines
Roundtrip price
$582
Distance
97 mi

Trenton to Islip Flights

The cheapest times to fly from Trenton to Islip

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Trenton to Islip are during the month of November. You can find some of the cheapest flights from Trenton to Islip with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Trenton to Islip

Sunday is one of the best days to book for cheap flights from Trenton to Islip: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Trenton to Islip

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Trenton to Islip in 2025. You can also book with separate airlines for your outbound and return journeys, from $117 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Trenton to Islip flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Trenton to Islip airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Mercer Airport (TTN) to MacArthur Airport (ISP) cost?
Grab a cheap one-way flight from $117 or cheap return flight from $583 from Mercer Airport (TTN) to MacArthur Airport (ISP) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight offers on this route.
What is the cheapest month to fly from Mercer Airport (TTN) to MacArthur Airport (ISP)?
November is the most affordable month to fly from TTN to ISP. Planning your trip for the off-season is often the key to finding better fares.
What is the cheapest airline that flies from Mercer Airport (TTN) to MacArthur Airport (ISP)?
Expedia's filter tool lets you easily compare airlines, flight times and fares all in one place. Tailor the search to your trip, then sort by "Price (lowest to highest)" to find the carrier with the cheapest TTN to ISP flight.
How many flights per day from Mercer Airport (TTN) to MacArthur Airport (ISP)?
There are no daily nonstop flights available from Mercer Airport (TTN) to MacArthur Airport (ISP). But you can opt for flights with layovers. Filter your search results on Expedia to include one or more stops, and you'll be soaring above the clouds before you know it.
What day of the week has the most flights from TTN to ISP?
Typically you'll find the most flight options available on a Friday. Tuesdays are often the quietest.* But this can change depending on the season, carrier and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Mercer Airport (TTN) to MacArthur Airport (ISP)?
To land at MacArthur Airport (ISP) on schedule, book a flight that leaves Mercer Airport (TTN) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Mercer Airport (TTN) to MacArthur Airport (ISP) last-minute?
Waiting until right before your break to book a flight from TTN to ISP often results in higher prices. While you might find some last-minute discounts, they aren't always guaranteed. Allow some flexibility in your schedule for a better chance of getting a bargain.
Is it cheaper to book a TTN to ISP flight and hotel package?
Opting for a TTN to ISP flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Choose from our extensive range of hotels and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Mercer Airport (TTN) to MacArthur Airport (ISP)?
In most cases, you can modify or cancel your TTN to ISP flight. However, there may be additional fees, especially if your booking was made more than 24 hours ago. Double-check your itinerary for the airline's fees and guidelines on flight changes, or if you'd like further information, head to our Customer Service portal.

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*Available to One Key members.