Denver, CO to Ontario, CA flights from $45

Flights starting at $45. Choose between Frontier Airlines, United Airlines, or American Airlines to find the best price.

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Cheapest one-way trip

$45

Cheapest nonstop round-trip

$45

Cheapest round-trip

$64

Average round-trip

$125

Nonstop flights in December

$45 – $391

Round trips

Denver DENOntario ONT

Frontier Airlines

$64
Denver DENOntario ONT

Frontier Airlines

$64

Updated:

818 miles
Distance
Duration
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Travelers usually depart from Denver International, Denver Union Station, Centennial Airport, or Rocky Mountain Metropolitan Airport when they travel from Denver to Ontario. Book your trip to arrive at Ontario International, Montclair (Ontario), Ontario Bus Stop, or Ontario, CA station. The distance between Denver and Ontario is 1317 km. The most popular airlines for this route are Frontier Airlines, United Airlines, American Airlines, Delta Air Lines, and Spirit Airlines. Denver and Ontario have 142 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 Denver to Ontario

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

United States COVID-19 travel restrictions

Latest COVID-19 travel restrictions in United States – 12/2022
Your trip summary

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

Departure

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 Denver to Ontario?
A one-way nonstop (direct) flight between Denver and Ontario takes around 2.4 hours.
What is the flight distance between Denver and Ontario?
The flight distance between Denver and Ontario is 1317 km.
What airlines offer nonstop (direct) flights between Denver and Ontario?
Several carriers operate flights between Denver and Ontario. Airlines offering nonstop (direct) flights include Frontier Airlines, United Airlines.
What are the most popular routes to and from Denver?
Travelers frequently search for route combinations, such as Denver and Las Vegas, Los Angeles, Chicago, Minneapolis, Dallas, Washington, D.C., Orlando, Phoenix, San Francisco, Houston, San Diego, Austin, Atlanta, Paris, Philadelphia, New York, Miami, London, Seattle, Tampa.
What are the most popular routes to and from Ontario?
Travelers frequently search for route combinations, such as Ontario and Orlando, Austin, Atlanta, Sacramento, Seattle, San Francisco, Washington, D.C., San Jose, San Antonio, Raleigh, Phoenix, Charlotte, Portland, Detroit, Philadelphia, Las Vegas, Oakland, Nashville, Chicago, Fort Lauderdale.
Which airports are there in Denver?
Denver is mainly served by Denver International. But there are other airports nearby, including Centennial Airport, Rocky Mountain Metropolitan Airport.
What airports are near Denver?
The main airport in Denver is Denver International. It is also served by Colorado Springs, Laramie Regional, Cheyenne Regional, Eagle County Regional, Pueblo Memorial.
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 buses and trains depart from Denver?
A number of bus and train companies depart from Denver, including Amtrak train, Greyhound.
Is it possible to combine flights, buses, and trains in one itinerary when traveling between Denver and Ontario?
What is Virtual Interlining and how do I use it?
Which airlines fly between Denver and Ontario?
When's the best time to travel between Denver and Ontario?
What flights operate between Denver and Ontario?
How many airports are there near Denver?
How many airports are there near Ontario?
Is it possible to reach Denver by bus or train?
What time do nonstop (direct) flights between Denver and Ontario depart?
What time do nonstop (direct) flights between Denver and Ontario arrive?
What time do flights between Denver and Ontario depart?
What time do flights between Denver and Ontario 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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