$104 Cheap Frontier Airlines flights Austin (AUS) to Ontario (ONT)

Finding cheap one-way Frontier Airlines flights from AUS to ONT from $104 on Expedia couldn’t be simpler — just filter by “Price (lowest to highest).” Or check out our affordable round-trip fares from $208 for your next exciting adventure.**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 Ontario are typically cheaper in the low-season months of January and April. Whether you’re in search of a round-trip or one-way ticket, you could find a better deal then.

Look for cheap Frontier Airlines flights from Austin-Bergstrom Intl. Airport (AUS) to Los Angeles - Ontario Intl. Airport (ONT) one to three months prior to your departure date. 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 class and journey, the ideal day to book a domestic flight is generally Sunday and the most expensive tends to be Monday. Passengers who book on a Sunday can save 6% on average compared to those who book 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.

To see if there’s a direct route from AUS to ONT with Frontier Airlines or another airline, select the “Nonstop” filter when looking for tickets.

To find the earliest departures from AUS to ONT with Frontier Airlines, sort your results by “Morning” and “Early Morning.” Booking an early flight generally 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.

Take a Frontier Airlines flight from Austin-Bergstrom Intl. Airport (AUS) to Ontario, and you’re most likely to touch down at Los Angeles - Ontario Intl. Airport (ONT). This is the airline’s main hub here.

A rewarding loyalty program and the opportunity to collect points through Frontier Miles are the start of the reasons to depart from AUS to ONT with Frontier Airlines. Plus, by joining Expedia’s free One Key™ program, you can receive OneKeyCash™* on top of 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.

Changes are usually free within 24 hours of booking, but your airline may charge you after that. For more information about modifying your reservation, head to your “Trips,” select your flight and click on “Manage Booking.” If you’d like the freedom to change your itinerary without additional costs, tick the “Changes included” and “No cancel fee” filters when organizing your next getaway.