$129 Cheap Delta flights Jacksonville (JAX) to Ontario (ONT)

Make use of the "Price (lowest to highest)" filter on Expedia to find cheap Delta Air Lines round-trip flights from $229 from JAX to ONT. Affordable one-way options from $129 are available too.**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.

For cheap Delta Air Lines fares from Jacksonville Intl. Airport (JAX) to Los Angeles - Ontario Intl. Airport (ONT), start searching one to three months before your intended 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 overall cost. Sunday is typically the most affordable, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your journey 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.

Sort your results by "Morning" and "Early Morning" to find the earliest flights from JAX to ONT. 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.

Delta Air Lines makes traveling from JAX to ONT more comfortable with a rewarding loyalty program and an excellent in-flight experience. You may even earn points with Delta SkyMiles. Be sure to join our free One Key™ rewards program to earn OneKeyCash™*, which can be redeemed on future trips.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.