$107 Cheap Delta flights Colorado Springs (COS) to Ontario (ONT)

Finding cheap one-way Delta Air Lines flights from COS to ONT from $107 on Expedia is a cinch — just filter by "Price (lowest to highest)." Or check out our affordable return fares from $202 for your next 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.

Look for affordable Delta Air Lines flights from Colorado Springs Airport (COS) to Los Angeles - Ontario Intl. Airport (ONT) one to three months prior to your departure. 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. No matter the fare class and journey, the best day to book a domestic flight is usually Sunday and the most expensive is typically 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 find the earliest departure from COS to ONT with Delta Air Lines, filter your results by "Early Morning" and "Morning." Choosing an early flight generally means you'll experience fewer 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 flying from COS to ONT more comfortable with an excellent in-flight experience and a rewarding loyalty program. You even have the chance to collect points with Delta SkyMiles. Remember to join Expedia's free One Key™ rewards program to earn OneKeyCash™*, which can be redeemed on future bookings.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.