Cheap Flights from Denver (DEN) to Ontario Intl. Airport (ONT)

View AU$137 flight on Mon, 31 Aug 2026Opens in a new window

Popular airlines from Denver International Airport (DEN) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from Denver (DEN) to Ontario Intl. Airport (ONT)

Prices were available within the past 7 days for one-way flights and round trip tickets for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$273 Return, found 1 day ago
AU$273
Return
found 1 day ago
Select Delta flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$273 found 1 day ago
Delta
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$316 Return, found 1 day ago
AU$316
Return
found 1 day ago
Select Delta flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$316 found 1 day ago
Delta
Tue, 23 June - Wed, 24 June
DEN
Denver
ONT
Ontario
AU$328 Return, found 20 hours ago
AU$328
Return
found 20 hours ago
Select Delta flight, departing Tue, 23 June from Denver to Ontario, returning Wed, 24 June, priced at AU$328 found 20 hours ago
Delta
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$335 Return, found 1 day ago
AU$335
Return
found 1 day ago
Select Delta flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$335 found 1 day ago
Delta
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$370 Return, found 1 day ago
AU$370
Return
found 1 day ago
Select Delta flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$370 found 1 day ago
Delta
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$370 Return, found 1 day ago
AU$370
Return
found 1 day ago
Select Delta flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$370 found 1 day ago
Delta
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$372 Return, found 1 day ago
AU$372
Return
found 1 day ago
Select Delta flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$372 found 1 day ago
United
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$377 Return, found 1 day ago
AU$377
Return
found 1 day ago
Select United flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$377 found 1 day ago
American Airlines
Wed, 10 June - Wed, 24 June
DEN
Denver
ONT
Ontario
AU$466 Return, found 3 days ago
AU$466
Return
found 3 days ago
Select American Airlines flight, departing Wed, 10 June from Denver to Ontario, returning Wed, 24 June, priced at AU$466 found 3 days ago
Alaska Airlines
Wed, 3 June - Sat, 6 June
DEN
Denver
ONT
Ontario
AU$498 Return, found 1 day ago
AU$498
Return
found 1 day ago
Select Alaska Airlines flight, departing Wed, 3 June from Denver to Ontario, returning Sat, 6 June, priced at AU$498 found 1 day ago

Frequently asked questions

How much does a flight from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) cost?
One-way flights typically cost between $1,289 and $3,052 and return flights often range between $1,289 and $3,052. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when Anaa (AAA) to Toronto, ON (YYZ-Pearson Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
September is typically the cheapest month to fly from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.), with average round-trip fares of approximately 539 CAD. This is about 18% lower than the average price throughout the year. September often sees lower prices as the summer travel rush ends and before the holiday season begins, leading to reduced demand. Other cheap months to fly from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) include February and April.*Averages based on flights available on Expedia in the last year.
Which airlines fly direct from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Enter DEN to ONT and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
How do I find cheap flights from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
To find a cheap flight from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best airline to fly with from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The best airline to fly with from Denver, CO (DEN-Denver Intl.) (DEN) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) (ONT) will differ from traveler to traveler. If you like to fly early, WN offers early morning flights. If price is the most important factor, F9 typically offers the lowest fares. WN offers the most daily flights from Denver, CO (DEN-Denver Intl.) (DEN) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) (ONT), which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
What is the best time to fly from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
When looking for the best time to fly from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.), it's a balance between price and popularity. Based on booking data from the past year, you'll find the cheapest flights in September or February, with average prices around 539 CAD for a round-trip. January is the most popular month for this route, meaning there are plenty of flight options available, though it's not the cheapest. If you prioritize savings, aim for September or February. If you prefer more flexibility with flight times and don't mind a slightly higher fare, January offers a high volume of flights.*Prices based on flights available on Expedia in the last year.
How many flights per day from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
When flying from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.), you'll find approximately 8 nonstop flights per day. For even more choice, look at flights that include layovers, as there are around 109 connecting flights per day. Some common connection points include Seattle - Tacoma Intl. (SEA), Harry Reid Intl. (LAS), and Sky Harbor Intl. (PHX).
What is the earliest flight from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The earliest flight from Denver International Airport (DEN) to Los Angeles - Ontario International Airport (ONT) typically departs at approximately 12:50 AM local time, operated by Delta. This is a seasonal service active in October, November, and December. An early departure like this can help maximize your time at your destination. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What day of the week has the most flights from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
You'll typically find the most flights from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) on a Friday, with around 92 flights available. This gives you plenty of options for your travel plans. Major airlines on this route include Southwest Airlines, Frontier Airlines, and Alaska Airlines. Friday offers notably more flight options compared to other days of the week.
What are the most popular departure times for flights from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The most popular departure times for flights from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) are in the early morning, from 6am to 9am. About 29% of passengers prefer this time window. Many major carriers, including Southwest Airlines and Frontier Airlines, offer flights during this window. These times work well because you can get an early start to your day and arrive at your destination with plenty of time.
How long does it take to fly from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Direct flights from DEN to ONT usually take about 2 hours 30 minutes, traveling roughly 817 miles. If you opt for a connecting flight, expect to add around 4 hours 50 minutes to your journey. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Select the "Business class" and "First class" filters when looking for DEN to ONT flights on Expedia. This is the easiest way to compare prices, routes and flight times for your trip.
How do I earn miles on a Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight with Expedia?
It's easy to earn miles on a Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for Ontario from Denver Intl. (DEN)?
If you're planning to travel to Ontario from Denver Intl. (DEN), you can fly into Los Angeles - Ontario Intl. (ONT) Some flights may connect through major hubs like Seattle - Tacoma Intl. (SEA), San Diego Intl. (SAN), Portland Intl. (PDX) before reaching Ontario. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) at the last minute?
Typically, booking a last minute flight from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight and hotel package?
Securing a Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
If you booked your Denver, CO (DEN-Denver Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.

Travel information

Origin airport
Denver Intl.
Destination airport
Ontario Intl. Airport
Airlines serving
Alaska Airlines, American Airlines, Delta, United
Return price
AU$272
Distance
1306 km
Average flight time
1 hour 21 mins

Book with confidence

Your quick guide to flights from Denver to Ontario Intl. Airport

Pick up great flights from Denver to Ontario Intl. Airport

With Expedia, you have your pick of flights a day with 20 airlines covering flights from Denver to Ontario Intl. Airport. Whether you’re on a business trip, a family holiday or a luxury break, just enter your travel dates, hit search then check out your choice of flights. Select from return, one way or multi-city flights, and use the advance search tool if you want a direct or refundable flight. You can narrow your search to show you just your preferred cabin class and airline, too. It’s all easy. You can book direct flights from Denver to Ontario Intl. Airport that take around hours.

Find cheap flights from Denver to Ontario Intl. Airport

From the great flight deals with prices currently ranging from AU$273 to AU$498, you can choose to see the cheapest flights first. Generally, you can book the cheapest flights from Denver to Ontario Intl. Airport around 4 to 6 weeks in advance. If your travel dates are flexible, try to avoid weekends and peak seasons – when you are more likely to grab the lowest prices. Even last minute, there are some impressive deals. The cheapest time to fly to Ontario Intl. Airport is normally in June.

Reasons to book your flight from Denver to Ontario Intl. Airport with Expedia

Expedia makes it easy to find, book, and travel, with everything you need all in one place. When you enter your travel details, find fantastic deals just for you on flight tickets from Denver to Ontario Intl. Airport across all the main airline carriers, so you can save time, dollars, and hassle finding the perfect flight. If you think your plans could change, choose refundable flights so any changes won’t cost you more. Book your flight to Ontario Intl. Airport right now and, if you join Expedia Rewards, you earn points this time and every time you travel with Expedia.

Your quick guide to flights from Denver to Ontario Intl. Airport

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