$157 Cheap Frontier Airlines flights Atlanta (ATL) to Islip (ISP)

Set the "Price (lowest to highest)" filter on Expedia to find cheap Frontier Airlines return flights from $266 from ATL to ISP. Affordable one-way fares from $157 are also on offer.**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.

To find cheap Frontier Airlines fares from Hartsfield-Jackson Atlanta Intl. Airport (ATL) to MacArthur Airport (ISP), start searching one to three months before your planned departure. Reserving domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also impact the price you pay. Sunday is usually the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your flight on a Sunday.**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 ATL to ISP with Frontier Airlines, sort your results by "Morning" and "Early Morning." Booking an early flight usually 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.

Travel from ATL to ISP with Frontier Airlines and look forward to a range of perks including a rewarding loyalty program. When booking through Expedia as a Frontier Miles and One Key™ member, you can also earn OneKeyCash™* to redeem on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.