Cheap Frontier Airlines flights Ontario (ONT) to Newark Liberty Intl. Airport (EWR)

Set the "Price (lowest to highest)" filter on Expedia to find cheap Frontier Airlines return flights from ONT to EWR. Affordable one-way options 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.

Start searching one to three months ahead of your departure date to find cheaper fares on Frontier Airlines flights from Los Angeles - Ontario Intl. Airport (ONT) to Liberty Intl. Airport (EWR). 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.* Get the timing right, 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.

Sort your results by "Early Morning" and "Morning" to see the earliest departures from ONT to EWR. Setting 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.

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