S$128 Cheap Flights from Denver to Ontario

View S$128 flight on Tue, 21 Apr, 2026Opens in a new window

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

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Cheap Flights from Denver to Ontario (DEN-ONT)

Prices were available within the past 7 days and start at S$128 for one-way flights and S$255 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 21 Apr - Wed, 22 Apr
DEN
Denver
ONT
Ontario
S$255 Return, found 1 hour ago
S$255
Return
found 1 hour ago
Select Delta flight, departing Tue, 21 Apr from Denver to Ontario, returning Wed, 22 Apr, priced at S$255 found 1 hour ago
Delta
Tue, 21 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$278 Return, found 1 hour ago
S$278
Return
found 1 hour ago
Select Delta flight, departing Tue, 21 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$278 found 1 hour ago
Delta
Tue, 21 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$298 Return, found 1 hour ago
S$298
Return
found 1 hour ago
Select Delta flight, departing Tue, 21 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$298 found 1 hour ago
Delta
Sat, 18 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$301 Return, found 1 hour ago
S$301
Return
found 1 hour ago
Select Delta flight, departing Sat, 18 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$301 found 1 hour ago
Delta
Sat, 7 Feb - Sun, 22 Feb
DEN
Denver
ONT
Ontario
S$310 Return, found 2 days ago
S$310
Return
found 2 days ago
Select Delta flight, departing Sat, 7 Feb from Denver to Ontario, returning Sun, 22 Feb, priced at S$310 found 2 days ago
United
Tue, 21 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$322 Return, found 1 hour ago
S$322
Return
found 1 hour ago
Select United flight, departing Tue, 21 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$322 found 1 hour ago
United
Tue, 21 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$329 Return, found 1 hour ago
S$329
Return
found 1 hour ago
Select United flight, departing Tue, 21 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$329 found 1 hour ago
United
Tue, 21 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$335 Return, found 1 hour ago
S$335
Return
found 1 hour ago
Select United flight, departing Tue, 21 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$335 found 1 hour ago
Alaska Airlines
Thu, 23 Apr - Fri, 24 Apr
DEN
Denver
ONT
Ontario
S$385 Return, found 1 hour ago
S$385
Return
found 1 hour ago
Select Alaska Airlines flight, departing Thu, 23 Apr from Denver to Ontario, returning Fri, 24 Apr, priced at S$385 found 1 hour ago
American Airlines
Tue, 21 Apr - Sat, 25 Apr
DEN
Denver
ONT
Ontario
S$393 Return, found 1 hour ago
S$393
Return
found 1 hour ago
Select American Airlines flight, departing Tue, 21 Apr from Denver to Ontario, returning Sat, 25 Apr, priced at S$393 found 1 hour ago

Find the cheapest month to fly from Denver (DEN) to Ontario (ONT)

February is typically the cheapest month to fly

From S$62 - S$132 per traveller.

Frequently asked questions

How much is a flight from Denver Intl. Airport (DEN) to Ontario Airport?
Round-trip tickets from DEN to Ontario Airport start from S$255. This price is based on fares quoted within the last 7 days on Expedia for flights departing within the next year — book ASAP to avoid missing out. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from DIA airport to ONT?
Most flights can be cancelled online, but every air carrier has different terms and conditions. If you do decide to cancel your flight, check out our Customer Service Portal and follow the instructions.
How do I find cheap flights from DEN to ONT that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you're searching for Denver Airport to Los Angeles - Ontario Intl. Airport (ONT) flights, you'll see a "no change fees" filter for you to select.
How far is the flight from Denver Airport to ONT?
A flight distance of just 1,300 kilometres separates Denver and Ontario. Once you're up in the skies, you won't get a chance to do much more than read the magazine in your seat pocket.
Which airlines fly direct from DEN to Los Angeles - Ontario Intl. Airport (ONT)?
A popular airline that flies from DEN to Ontario Airport is Southwest Airlines (WN). It offers 99 monthly flights. Operating 60 flights each month along this route, Frontier Airlines (F9) is another top pick.
Are DEN to ONT flight tickets cheaper when they're purchased at the last minute?
Late planners can sometimes find a bargain, with some of the cheapest airfares from Denver Airport to Ontario Airport surfacing a few weeks prior to the departure date. If you'd rather book ahead, Expedia compares and updates the best flight deals regularly — as early as 12 months in advance in some cases. It depends on the carrier though, as not all airlines quote prices that far in advance.

Travel information

Origin airport
Denver Intl.
Destination airport
Los Angeles - Ontario Intl.
Return price
S$255
Distance
1306 km
Average flight time
1 hour 29 mins

Book with confidence

Perfect flights from Denver to Ontario

Your Journey from Denver to Ontario

Start your unforgettable journey with Expedia. Our broad selection of flights from Denver to Ontario caters to every travel need. Whether you're yearning for a romantic escape, a solo adventure, or a cultural immersion, we've got you covered.
 

Choosing Your Ideal Flight

With Expedia, you have access to a wide range of airlines, including Delta, United, American Airlines, Alaska Airlines. Our selection of flights from Denver Intl. to Los Angeles - Ontario Intl. caters to every traveler's requirements, ensuring your journey aligns with your schedule. With options from 20 airlines, you're bound to find the perfect flight.
 

Maximizing Value with Denver to Ontario Flights

Experience the joy of finding cheap flights from Denver Intl. to Los Angeles - Ontario Intl. that fit your budget. Keep an eye out for our special deals and discounts, and check our flexible one-way fares from S$128 and roundtrip prices from S$255*.
 

Pre-Flight Essentials

Ensure a smooth journey from Denver to Ontario with Expedia. From information about check-in times and in-flight amenities to guidance on baggage policies, we provide all the essentials to prepare you for your flight.
 

Experience the Vibrant Ontario

Picture yourself stepping off the plane in Ontario and immersing yourself in the unique atmosphere of . From local markets to cultural festivals, each city offers its distinct charm. Make the most of your trip by exploring local attractions and indulging in the local cuisine. With Expedia, explore all this and more, tailored to your budget.
 

Added Convenience on Your Denver to Ontario Flight

Traveling with Expedia is more than just a flight. We offer details about in-flight amenities, baggage policies, and more to ensure a smooth and hassle-free journey. Choose from our variety of airlines and embark on a memorable journey from Denver to Ontario.
 

Beyond the Flight – Exploring Ontario

With Expedia, your adventure extends beyond the flight. Explore Ontario at your own pace by renting a car or booking a hotel. Discover hidden gems off the beaten path and create unforgettable memories.
 

Book Your Flight from Denver to Ontario with Confidence

Planning your next great adventure is a breeze with Expedia. Our user-friendly platform, unbeatable prices, and round-the-clock customer support make your travel experience seamless and stress-free. Embark on your journey from Denver to Ontario with confidence. Book your travel arrangements with Expedia today.
 
*Note: Prices may vary based on availability and are subject to change.
Perfect flights from Denver to Ontario

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