Cheap Frontier Airlines flights Louisville (SDF) to Ontario (ONT)

Finding cheap one-way Frontier Airlines flights from SDF to ONT on Expedia is simple — 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.

January is one of the cheapest months to fly to Ontario with Frontier Airlines. You could also find great prices on return and one-way fares in April.

To find cheap Frontier Airlines fares from Louisville Intl. Airport (SDF) to Los Angeles - Ontario Intl. Airport (ONT), 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 influence the price you pay. Sunday is typically the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your trip 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.

Click on our “Nonstop” filter when looking for direct Frontier Airlines flights from SDF to ONT. It’s also a good way to compare other airlines offering the same direct trip.

Filter your results by “Early Morning” and “Morning” to find the earliest departures from SDF to ONT. Heading off early means you’re 20% 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.

Los Angeles - Ontario Intl. Airport (ONT) is the main Ontario gateway for Frontier Airlines flights from Louisville Intl. Airport (SDF).

Offering a rewarding loyalty program, Frontier Airlines is a favorite of many travelers departing from SDF to ONT. Plus, if you’re a Frontier Miles and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights along with your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

It’s generally possible to cancel or reschedule your flight, although additional charges may apply if you booked over 24 hours ago. Need to keep your options open? Use our “Changes included” and “No cancel fee” filters to find flights that won’t charge you extra if you need to revise your plans. To update your itinerary, head to “Trips,” select your flight and click on “Manage Booking” for more details.