Cheap Flights from Ontario to Denver

Cheapest flights from Ontario to Denver

Flaut.Travel was designed and developed by a team dedicated to making the process of searching, comparing and booking airline tickets as easy and convenient as possible. Our service helps travelers to find and buy the cheapest flights from Ontario to Denver. We have connected more than 40 airlines and airline ticketing agencies to help you find the most suitable and affordable flight option.

Cheapest one way flight

$38

Frontier Airlines

Direct flight

2h 26m

01/11/2026

The cheapest one-way flight from Ontario to Denver departs on 01/11/2026, is operated by Frontier Airlines and costs $38

Cheapest round trip flight

$57

Frontier Airlines

Direct flight

5h 22m

01/24/2026

The cheapest roundtrip flight from Ontario to Denver departs on 01/24/2026, is operated by Frontier Airlines and costs $57

The fastest flight

2h 15m

Fastest flight from Ontario to Denver takes 2h 15m

Direct flights

Several times a week

There are direct flights on this route 3 days a week: Su, Tu, and Sa

Earliest flight

5:05 AM

Latest flight

4:15 PM

Direct flights count

48

Distance

1289km

Timezone difference

1h

The distance between Ontario and Denver is 1289km (799 miles). There are 48 direct flights from Ontario to Denver. The time difference between Ontario and Denver is 1h. Flights from Ontario begin at 5:05 AM. The latest flight from Ontario departs at 4:15 PM

Remember that on average the ideal time to book flights is 2 months before departure!

Airfare from Ontario to Denver by month

We carefully collect statistics on the search and pricing of airlines and, based on these data, we make an assumption about future prices. Thus, you can better understand which season is the cheapest to fly from Ontario to Denver

January 2026

Lowest price

on average:

$38

Avg Price

Airlines operating on route

The Ontario — Denver route is served by a wide range of airlines: 4 in total, including Southwest Airlines, United Airlines, Frontier Airlines, and Alaska Airlines. Competition among carriers gives passengers the opportunity to find tickets at attractive fares — with prices starting from $38. Our service helps compare all available offers within seconds and choose the most convenient option. You can filter flights by price, departure time, or baggage rules to make your trip as comfortable as possible. With so many airlines, there’s always a chance to catch special promotions and save.

Starting at $205

Starting at $203

Starting at $38

Starting at $220

Direct Flights from Ontario to Denver

A direct flight is the most convenient and comfortable way to fly from Ontario to Denver, despite the fact that sometimes flights with transfers can cost significantly less.

Los Angeles — Denver

LAX — DEN

01/02/2026

Departure

Direct flight

WN163

Starting at $243

Los Angeles — Denver

LAX — DEN

01/04/2026

Departure

Direct flight

UA2146

Starting at $323

Ontario — Denver

ONT — DEN

01/11/2026

Departure

Direct flight

UA2446

Starting at $203

Ontario — Denver

ONT — DEN

09/15/2026

Departure

Direct flight

UA1263

Starting at $266

Ontario — Denver

ONT — DEN

09/08/2026

Departure

Direct flight

UA2234

Starting at $284

Schedule of direct flights from Ontario to Denver

A direct flight is the easiest way to get to your destination. The following airlines operate non-stop flights from Ontario to Denver:

Unable to find information about the schedule of direct flights from

Ontario airports overview

Ontario International Airport

•

ONT

5km

•

Denver airports overview

Centennial Airport

•

APA

1km

Denver International Airport

•

DEN

30km

•

Frequently asked questions (FAQ)

Answers to questions about the route that travelers are most interested in.

How much is the cheapest flight ticket from Ontario to Denver?

The cheapest flight ticket from Ontario to Denver according to data for the last 48 hours costs $38

When is the best time to buy air tickets on the route Ontario — Denver?

Often the best time to buy tickets from Ontario to Denver is 2 months before departure.

When is the cheapest time of year to fly from Ontario to Denver?

Based on statistics over the past years, the lowest prices for flights from Ontario to Denver can be found flying in these months: January.

How long does it take to fly from Ontario to Denver?

The fastest flights from Ontario to Denver start from 2 hours 15 minutes in the air.

Which airline can fly direct from Ontario to Denver?

The following airlines operate direct flights on the route Ontario — Denver: Southwest Airlines, United Airlines

Special offers and sales on air tickets from Ontario to Denver

We keep tight track on airlines' pre-holidays sales and other special offers occurences all the time to let you save maximum amount of funds while traveling to your family or just going out on vacation.

We couldn't find any special offers for flights from Ontario to Denver

Alternative routes

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Cheapest one way flight

$38

Frontier Airlines

Direct flight

2h 26m

01/11/2026

The cheapest one-way flight from Ontario to Denver departs on 01/11/2026, is operated by Frontier Airlines and costs $38

Cheapest round trip flight

$57

Frontier Airlines

Direct flight

5h 22m

01/24/2026

The cheapest roundtrip flight from Ontario to Denver departs on 01/24/2026, is operated by Frontier Airlines and costs $57

The fastest flight