$379 Cheap Flights from Champaign (CMI) to Ontario (ONT)

View $379 flight on Wed, Aug 6, 2025Opens in a new window

Popular airlines from Champaign, IL (CMI-University Of Illinois Urbana-Champaign Williard) to Los Angeles - Ontario Intl. Airport (ONT)

Cheap Flights from Champaign to Ontario (CMI-ONT)

Prices were available within the past 7 days and start at $379 for one-way flights and $434 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

American Airlines
Tue, Jul 29 - Tue, Aug 5
CMI
Champaign
ONT
Ontario
$434 Roundtrip, found 3 days ago
$434
Roundtrip
found 3 days ago
Select American Airlines flight, departing Tue, Jul 29 from Champaign to Ontario, returning Tue, Aug 5, priced at $434 found 3 days ago
American Airlines
Tue, Jul 29 - Tue, Aug 5
CMI
Champaign
ONT
Ontario
$440 Roundtrip, found 3 days ago
$440
Roundtrip
found 3 days ago
Select American Airlines flight, departing Tue, Jul 29 from Champaign to Ontario, returning Tue, Aug 5, priced at $440 found 3 days ago
American Airlines
Tue, Jul 29 - Tue, Aug 5
CMI
Champaign
ONT
Ontario
$456 Roundtrip, found 3 days ago
$456
Roundtrip
found 3 days ago
Select American Airlines flight, departing Tue, Jul 29 from Champaign to Ontario, returning Tue, Aug 5, priced at $456 found 3 days ago
American Airlines
Fri, Aug 1 - Wed, Aug 6
CMI
Champaign
ONT
Ontario
$464 Roundtrip, found 5 days ago
$464
Roundtrip
found 5 days ago
Select American Airlines flight, departing Fri, Aug 1 from Champaign to Ontario, returning Wed, Aug 6, priced at $464 found 5 days ago
American Airlines
Fri, Aug 29 - Mon, Sep 1
CMI
Champaign
ONT
Ontario
$494 Roundtrip, found 2 hours ago
$494
Roundtrip
found 2 hours ago
Select American Airlines flight, departing Fri, Aug 29 from Champaign to Ontario, returning Mon, Sep 1, priced at $494 found 2 hours ago
American Airlines
Fri, Aug 29 - Mon, Sep 1
CMI
Champaign
ONT
Ontario
$511 Roundtrip, found 3 days ago
$511
Roundtrip
found 3 days ago
Select American Airlines flight, departing Fri, Aug 29 from Champaign to Ontario, returning Mon, Sep 1, priced at $511 found 3 days ago
American Airlines
Tue, Jul 29 - Tue, Aug 5
CMI
Champaign
ONT
Ontario
$513 Roundtrip, found 3 days ago
$513
Roundtrip
found 3 days ago
Select American Airlines flight, departing Tue, Jul 29 from Champaign to Ontario, returning Tue, Aug 5, priced at $513 found 3 days ago
American Airlines
Tue, Jul 29 - Tue, Aug 5
CMI
Champaign
ONT
Ontario
$519 Roundtrip, found 3 days ago
$519
Roundtrip
found 3 days ago
Select American Airlines flight, departing Tue, Jul 29 from Champaign to Ontario, returning Tue, Aug 5, priced at $519 found 3 days ago
American Airlines
Sat, Aug 30 - Tue, Sep 16
CMI
Champaign
ONT
Ontario
$524 Roundtrip, found 5 hours ago
$524
Roundtrip
found 5 hours ago
Select American Airlines flight, departing Sat, Aug 30 from Champaign to Ontario, returning Tue, Sep 16, priced at $524 found 5 hours ago
American Airlines
Fri, Sep 26 - Mon, Sep 29
CMI
Champaign
ONT
Ontario
$528 Roundtrip, found 6 days ago
$528
Roundtrip
found 6 days ago
Select American Airlines flight, departing Fri, Sep 26 from Champaign to Ontario, returning Mon, Sep 29, priced at $528 found 6 days ago
Flights from Champaign (CMI) to Ontario (ONT)
Origin airport
University Of Illinois Urbana-Champaign Williard
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
American Airlines
Roundtrip price
$434
Distance
1660 mi

Champaign to Ontario Flights

The cheapest times to fly from Champaign to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Champaign to Ontario are during the month of July. You can find some of the cheapest flights from Champaign to Ontario with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Champaign to Ontario

Sunday is one of the best days to book for cheap flights from Champaign to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Champaign to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Champaign to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $379 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Champaign to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Champaign to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Discover the latest flight deals from CMI to ONT by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from CMI to ONT?
The cheapest flights from CMI to ONT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from CMI to ONT?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from CMI to ONT. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT)?
Direct flights from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT) aren't available daily, so you'll have to take a flight with a layover. Explore your options with our filter tool. Enter your dates and select either "1 Stop" or "2+ Stops."
What day of the week has the most flights from CMI to ONT?
Friday is generally the busiest day for flights, while Tuesday tends to be the quietest.* Remember that flight schedules can vary based on various factors, including the airline and season.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT)?
To avoid potential delays on the University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT) route, travel before 3 PM. Departures after this hour are 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Last-minute bookings from CMI to ONT are generally more expensive. To secure the lowest rates, start searching for flights well in advance. That being said, if you're flexible with your travel dates, you may land a cheap ticket just before your departure.
Is it cheaper to book a CMI to ONT flight and hotel package?
You'll generally save money by securing a CMI to ONT flight and hotel package compared to booking separately. In fact, travelers could save hundreds of dollars by bundling with Expedia. And it's simple to manage everything in one convenient place. After choosing your preferred accommodations and flights, consider adding extras such as tours, activities and car rentals.
Can I cancel or change the date of my flight from University Of Illinois Urbana-Champaign Williard Airport (CMI) to Los Angeles - Ontario Intl. Airport (ONT)?
Generally, it's possible to reschedule or cancel your CMI to ONT flight. However, if the booking was made more than 24 hours ago, additional charges may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find more details on our Customer Service portal.

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*Available to One Key members.