$124 Cheap Frontier Airlines flights Chicago (MDW) to Islip (ISP)

Finding cheap one-way Frontier Airlines flights from MDW to ISP from $124 on Expedia is a cinch --- just filter by "Price (lowest to highest)." Or check out our budget-friendly round-trip fares from $236 for your next exciting getaway.**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 Midway Intl. Airport (MDW) to MacArthur Airport (ISP). You can save 25% by booking your domestic flight 34 to 86 days in advance versus last-minute reservations made 6 to 12 days out. You could also reduce costs by buying your fare on a Sunday, as it's 6% cheaper on average than a Monday, the most expensive day to book.* Nail your timing, and you can enjoy significant savings on domestic flights.*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.

Filter your results by "Morning" and "Early Morning" to find the earliest flights from MDW to ISP. Taking off early means you're less likely to experience cancellations.**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.

Fly from MDW to ISP with Frontier Airlines and you can look forward to a host of benefits starting with a rewarding loyalty program. When you book through Expedia as a Frontier Miles and One Key™ member, you can also earn OneKeyCash™* to spend on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.