$108 Cheap Frontier Airlines flights Denver (DEN) to Trenton (TTN)

Use the "Price (lowest to highest)" filter on Expedia to search for cheap Frontier Airlines round-trip flights from $215 from DEN to TTN. Affordable one-way options from $108 are available as well.**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 Denver Intl. Airport (DEN) to Mercer Airport (TTN). 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.* Time it well, 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.

Filter your results by "Morning" and "Early Morning" to find the earliest flights from DEN to TTN. Heading 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.

A rewarding loyalty program and the chance to rack up points through Frontier Miles are the start of the reasons to depart from DEN to TTN with Frontier Airlines. Plus, when you sign up to our One Key™ program, you can earn OneKeyCash™* alongside any airline loyalty program earnings. It's yours to spend on future travel plans.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.