$143 Cheap Frontier Airlines flights Buffalo (BUF) to Islip (ISP)

Landing cheap one-way Frontier Airlines flights from BUF to ISP from $143 on Expedia is a breeze --- just filter by "Price (lowest to highest)." Or check out our affordable return fares from $222 for your next exciting vacation.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Begin your search one to three months before your departure to score cheap fares on Frontier Airlines flights from Buffalo Niagara Intl. Airport (BUF) to MacArthur Airport (ISP). You can save 25% by booking your domestic flight 34 to 86 days in advance compared to last-minute reservations made 6 to 12 days out. You could also cut costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Get your timing right, and you can enjoy significant savings on domestic trips.*Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

To find the earliest departures from BUF to ISP with Frontier Airlines, sort your results by "Morning" and "Early Morning." Choosing an early flight generally means cancellations are less likely.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

With a rewarding loyalty program, Frontier Airlines is a top pick for many passengers journeying from BUF to ISP. Plus, if you're a Frontier Miles and One Key™ member booking through Expedia, you can earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.