$54 Cheap Frontier Airlines flights Denver (DEN) to Ontario (ONT)

Grab cheap return Frontier Airlines flights from $103 from DEN to ONT by sorting your results from “Price (lowest to highest)” on Expedia. Or search for deals from $54 for a one-way trip.**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 usually more affordable in the quieter months of January and April. Whether you’re searching for a one-way or a return ticket, you could find a better deal then.

Start searching one to three months ahead of your travel date to get cheap fares on Frontier Airlines flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT). 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 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 journeys.*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.

Skip the layovers and fly from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) on any of Frontier Airlines’s 10 weekly direct flights. Use Expedia’s “Nonstop” and “Airline” filters to find the Frontier Airlines flight that’ll arrive at ONT at your preferred time.

It takes around 2h 31m to travel nonstop from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) with Frontier Airlines.

If it’s flexibility you’re after, Wednesday offers the most choice for Frontier Airlines flights from Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT). You can select from 2 different departures.

Leaving DEN at 8:07AM UTC-7, the first Frontier Airlines flight to ONT lands at 9:40AM UTC-8. Traveling early means you’re less likely to experience delays.* After something later? The last Frontier Airlines flight from DEN to ONT departs at 10:15PM UTC-7 and touches down at 11:47PM UTC-8.*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.

When heading from Denver Intl. Airport (DEN) to Ontario with Frontier Airlines, you’re most likely to land at Los Angeles - Ontario Intl. Airport (ONT). This is the airline’s main hub here. Other nearby airports like Los Angeles Intl. Airport (LAX) and John Wayne Airport (SNA) may have lower fares, so it’s a good idea to consider all available options on Expedia.

Journey from DEN to ONT with Frontier Airlines and enjoy a range of benefits starting with a rewarding loyalty program. When booking through Expedia as a Frontier Miles and One Key™ member, you may also earn OneKeyCash™* to redeem on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

For the Denver Intl. Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT) route, Frontier Airlines typically operates Airbus A321neo and Airbus A320neo planes. Remember that last-minute changes can occur for operational purposes, so your flight could be on a different aircraft.

Changes are often free within 24 hours of making a booking, but your airline may charge you after that. For more information about altering your reservation, go to your “Trips,” select your flight and click on “Manage Booking.” If you want the freedom to change your itinerary without being charged, tick the “No cancel fee” or “Changes included” filter when planning your next adventure.