Cheap flights from Ontario, CA to Denver, CO

Flights starting at $46. Choose between American Airlines, Frontier Airlines, or United Airlines to find the best price.

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Cheapest one-way trip

$46

Cheapest nonstop round-trip

$46

Cheapest round-trip

$64

Average round-trip

$148

Nonstop flights in December

$46 – $667

Round trips

Ontario ONTDenver DEN

Frontier Airlines

$64
Ontario ONTDenver DEN

Frontier Airlines

$64

Updated:

818 miles
Distance
Duration
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Travelers usually depart from Ontario International, Montclair (Ontario), Ontario Bus Stop, or Ontario, CA station when they travel from Ontario to Denver. Book your trip to arrive at Denver International, Denver Union Station, Centennial Airport, or Rocky Mountain Metropolitan Airport. The distance between Ontario and Denver is 1317 km. The most popular airlines for this route are American Airlines, Frontier Airlines, United Airlines, JetBlue Airways, and Delta Air Lines. Ontario and Denver have 401 direct flights per week.

Weekly direct flights

MondaysTuesdaysWednesdaysThursdaysFridaysSaturdaysSundays
Direct flights4443444
Fly direct with

Frontier Airlines on Mondays, Tuesdays, Wednesdays, Thursdays, Fridays, Saturdays, and Sundays.

United Airlines on Mondays, Tuesdays, Wednesdays, Thursdays, Fridays, Saturdays, and Sundays.

Check-in for a flight from Ontario to Denver

NameCarrier codeIATA CodePassport needed during bookingOnline check-in available
American AirlinesAALAAYesNo
Frontier AirlinesFFTF9NoOpens 24 days before flight
Closes 1 hours before flight
United AirlinesUALUAYesNo
JetBlue AirwaysJBUB6YesOpens 24 days before flight
Closes 2 hours before flight
Delta Air LinesDALDLYesOpens 24 days before flight
Closes 1 hours before flight

United States COVID-19 travel restrictions

Your trip summary

Most travelers from Ontario, ONT can enter Denver, DEN.

Departure

Additional information
  • Masks are recommended certain settings

Return

Travel restrictions
  • Travel is allowed
  • Proof of a negative pre-departure COVID-19 test result is not required
  • Quarantine is not required

Information is provided as guidance only and accurate at the time of publishing. Always check government websites and airline materials before booking and traveling.

Learn more about COVID-19 restrictions in United States in our dedicated Stories article.

Frequently asked questions

How long does it take to travel from Ontario to Denver?
A one-way nonstop (direct) flight between Ontario and Denver takes around 2.3 hours.
What is the flight distance between Ontario and Denver?
The flight distance between Ontario and Denver is 1317 km.
What airlines offer nonstop (direct) flights between Ontario and Denver?
Several carriers operate flights between Ontario and Denver. Airlines offering nonstop (direct) flights include Frontier Airlines, United Airlines.
What are the most popular routes to and from Ontario?
Travelers frequently search for route combinations, such as Ontario and Orlando, Austin, Las Vegas, Atlanta, Sacramento, San Francisco, Seattle, San Antonio, Guadalajara, Charlotte, New Orleans, Fort Lauderdale, Philadelphia, Washington, D.C., Oakland, San Jose, Detroit, Minneapolis, Chicago, Houston.
What are the most popular routes to and from Denver?
Travelers frequently search for route combinations, such as Denver and Chicago, Dallas, Minneapolis, Los Angeles, Washington, D.C., Houston, Orlando, San Francisco, Atlanta, Las Vegas, Austin, Phoenix, Philadelphia, San Diego, Miami, New York, Tampa, Detroit, Seattle, Salt Lake City.
What airports are near Ontario?
The main airport in Ontario is Ontario International. It is also served by San Diego International, Tijuana International, Ontario International, John Wayne, Hollywood Burbank, Palm Springs International, Imperial County, Santa Barbara Municipal, McClellan–Palomar, Long Beach.
What airports are near Denver?
The main airport in Denver is Denver International. It is also served by Colorado Springs, Laramie Regional, Pueblo Memorial, Cheyenne Regional, Eagle County Regional.
Is it possible to combine flights, buses, and trains in one itinerary when traveling between Ontario and Denver?
Yes, it's possible to combine different modes of transport between Ontario and Denver thanks to our Virtual Interlining technology. Making use of not only flights but also trains and buses between Ontario and Denver can give rise to new adventures. Read more about how Virtual Interlining works on Kiwi.com Stories.
What is Virtual Interlining and how do I use it?
Virtual Interlining provides a revolutionary way of traveling. You can combine different modes of transport like flights, trains, and buses into one itinerary. And this often saves money. Thanks to the world's largest carrier database, the Kiwi.com search function enables anyone to mix and match different modes of transport easily.
Which airlines fly between Ontario and Denver?
When's the best time to travel between Ontario and Denver?
What flights operate between Ontario and Denver?
How many airports are there near Ontario?
How many airports are there near Denver?
What time do nonstop (direct) flights between Ontario and Denver depart?
What time do nonstop (direct) flights between Ontario and Denver arrive?
What time do flights between Ontario and Denver depart?
What time do flights between Ontario and Denver arrive?

Planning a trip? Thanks to our Virtual Interlining algorithm, we offer billions of route combinations between any A and any B in the world by plane, train, and bus. Find the cheapest routes and best deals for you, as well as the best dates on which to travel.

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