Cheap Frontier Airlines flights Denver (DEN) to Louisville (SDF)

Finding cheap one-way Frontier Airlines flights from DEN to SDF on Expedia is easy — just filter by “Price (lowest to highest).” Or check out our budget-friendly round-trip fares for your next 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.

Frontier Airlines flights to Louisville are usually cheaper in the quieter months of January and December. Whether you need a one-way or a return ticket, you could find a better deal then.

Look for affordable Frontier Airlines flights from Denver Intl. Airport (DEN) to Louisville Intl. Airport (SDF) one to three months prior to your departure. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. Regardless of fare type and itinerary, the ideal day to book a domestic flight is usually Sunday and the most expensive day tends to be Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**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.

Use our “Nonstop” filter when browsing for direct Frontier Airlines flights from DEN to SDF. It’s also a good way to compare other airlines offering the same direct route.

Filter your results by “Morning” and “Early Morning” to see the earliest flights from DEN to SDF. Setting off early means flight 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.

Frontier Airlines flights from Denver Intl. Airport (DEN) to Louisville come in to Louisville Intl. Airport (SDF). This is the main entry point here.

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

Depending on the type of fare you purchased, a fee will generally apply if you cancel or reschedule your flight more than 24 hours after it has been confirmed. To secure flexible fares, select our “No cancel fee” or “Changes included” filter while looking for flights. For additional information on canceling or changing your reservation, go to “Trips,” select your flight and tick “Manage Booking.”