$121 Cheap United flights Missoula (MSO) to Ontario (ONT)

You can discover budget-friendly return United Airlines flights from $241 from MSO to ONT by organizing your results from "Price (lowest to highest)" on Expedia. Or search for bargains from $121 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.

For cheap United Airlines fares from Missoula Intl. Airport (MSO) to Los Angeles - Ontario Intl. Airport (ONT), start searching one to three months before your planned departure. Securing 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 affect what you pay. Sunday is generally the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your trip 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.

Browse United Airlines's earliest flights from MSO to ONT by checking the "Morning" and "Early Morning" filters. Not only will you get to where you're going sooner, early departures are also 20% less likely to be canceled.**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.

Offering a rewarding loyalty program, United Airlines is a popular choice for many travelers departing from MSO to ONT. Plus, if you're a United Mileage Plus and One Key™ member booking through Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.