Cheap Flights from Denver International to Ontario International

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Compare Denver International to Ontario International flight deals

Find the cheapest month or even day of the year to fly to Ontario International

Book the best Ontario International fare with no extra fees

Flight deals Cheapest month Find the best route Route info FAQs Tips and advice

Flight deals from Denver International to Ontario International

Looking for a cheap last-minute deal or the best return flight from Denver International Airport to Ontario International Airport? If you want to travel next month, return fares start from Rs18,253. Find the lowest prices on one-way and return tickets right here.

Ontario.Rs9,127 per passenger.Departing Thu, 1 Oct.One-way flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Denver International on Thu, 1 Oct, arriving in Ontario International.Price includes taxes and charges.From Rs9,127, select.

Ontario.Rs9,127 per passenger.Departing Wed, 16 Sep.One-way flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Denver International on Wed, 16 Sep, arriving in Ontario International.Price includes taxes and charges.From Rs9,127, select.

Ontario.Rs9,133 per passenger.Departing Mon, 2 Nov.One-way flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Denver International on Mon, 2 Nov, arriving in Ontario International.Price includes taxes and charges.From Rs9,133, select.

Ontario.Rs12,279 per passenger.Departing Wed, 9 Dec.One-way flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Denver International on Wed, 9 Dec, arriving in Ontario International.Price includes taxes and charges.From Rs12,279, select.

Ontario.Rs21,712 per passenger.Departing Thu, 21 Jan.One-way flight with United.Outbound direct flight with United departs from Denver International on Thu, 21 Jan, arriving in Ontario International.Price includes taxes and charges.From Rs21,712, select.

Ontario.Rs21,874 per passenger.Departing Sat, 6 Feb.One-way flight with United.Outbound direct flight with United departs from Denver International on Sat, 6 Feb, arriving in Ontario International.Price includes taxes and charges.From Rs21,874, select.

Ontario.Rs49,697 per passenger.Departing Mon, 1 Mar.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Denver International on Mon, 1 Mar, arriving in Ontario International.Price includes taxes and charges.From Rs49,697, select.

Ontario.Rs49,858 per passenger.Departing Mon, 31 Aug.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Denver International on Mon, 31 Aug, arriving in Ontario International.Price includes taxes and charges.From Rs49,858, select.

Ontario.Rs58,755 per passenger.Departing Fri, 28 Aug.One-way flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from Denver International on Fri, 28 Aug, arriving in Ontario International.Price includes taxes and charges.From Rs58,755, select.

Ontario.Rs69,851 per passenger.Departing Sun, 16 May.One-way flight with Delta.Outbound indirect flight with Delta, departs from Denver International on Sun, 16 May, arriving in Ontario International.Price includes taxes and charges.From Rs69,851, select.

Ontario.Rs75,440 per passenger.Departing Thu, 1 Apr.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Denver International on Thu, 1 Apr, arriving in Ontario International.Price includes taxes and charges.From Rs75,440, select.

Ontario.Rs103,179 per passenger.Departing Sun, 16 May.One-way flight with United.Outbound direct flight with United departs from Denver International on Sun, 16 May, arriving in Ontario International.Price includes taxes and charges.From Rs103,179, select.

Find the cheapest month to fly from Denver International to Ontario International

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Denver International to Ontario International flights are currently cheapest in September.

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Direct flights from Denver International to Ontario International

Denver International to Ontario International: Alternative routes

Compare routes from Denver International to Ontario below. You may find an airport to fly into that's cheaper, faster, or easier than Ontario International.

Denver to Ontario: Flight information

The things to know before you go.

Cheapest flight found	Rs9,127
Cheapest month to fly	September
Average flight time	2 hrs, 23 mins
Most popular airline	Southwest Airlines
Average flights per week	70

Finding cheap flights from Denver International to Ontario International: Frequently asked questions

How much are return flights from Denver International to Ontario International?

The best price we found for a return flight from Denver International to Ontario International is Rs18,253. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.

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

2 hours and 23 minutes is the average flight time from Denver International to Ontario International.

Which airlines fly direct from Denver International to Ontario International?

Southwest Airlines, United and Frontier Airlines fly direct from Denver International to Ontario International.

How many flights are there a week from Denver International to Ontario International?

As of August 2026, there are 69 flights per week flying from Denver International to Ontario International.

When is the cheapest time to fly from Denver International to Ontario International?

The cheapest month to fly from Denver International to Ontario International is usually September.

Which upcoming date is cheapest to fly from Denver International Airport to Ontario International Airport on?

After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Denver International Airport to Ontario International Airport on Saturday, 19 September 2026.

Can I get a direct flight from Denver International Airport to Ontario International Airport?

Yes – the average flight time is 2 hours and 23 minutes.

How can I find the best flight deal to Ontario International?

We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Ontario International but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

When is the best time to book flights to Ontario?

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Ontario is around 40 days in advance, so don’t leave your flight to the last minute.

Which is the cheapest airline to fly from Denver International Airport to Ontario International with?

Currently, Frontier Airlines offers the cheapest flight tickets to Ontario International.

Flying from Denver International Airport (DEN) to Ontario International Airport (ONT): what you need to know

Around 2 hours 20 minutes is how long you can expect to be travelling on a direct flight from Denver International Airport to Ontario International Airport.
Ontario is one hour behind Denver and is in the UTC-8 timezone.
Flights from DEN to ONT start at 07:40 — the first with Frontier Airlines. The latest departure is at 22:55 with Southwest Airlines. In total, you can choose from 36 weekly Denver International Airport to Ontario International Airport flights.
Get to the airport on time so you don't miss your DEN to ONT flight. Be there at least two hours ahead for international flights and an hour early for domestic departures to prevent a last-minute sprint to your gate.
During popular months like July, it's best to get to the airport well in advance. Plan to arrive two hours before a domestic departure and four hours ahead of an international flight whenever you're travelling during a peak period in general.
You can travel nonstop to Ontario, the United States. Prepare for takeoff with one of these airlines that operate direct flights from Denver International Airport to Ontario International Airport:
Most passengers choose to travel with United on this route.
With a reliable 87.59% of services arriving as planned, United has the best on-time record for DEN to ONT flights.
Think about adding a stopover when booking your ticket from Denver International Airport to Ontario International Airport. Just deselect 'Direct flights only' to break up your journey, or enjoy a detour to a new and interesting place. Here's where you can stop between DEN and ONT:
- Phoenix Sky Harbour Airport
- Harry Reid International Airport
- Salt Lake City Airport

How to find the cheapest flights from Denver International Airport (DEN) to Ontario International Airport (ONT)

The cheapest price we've seen for a one-way Denver International Airport to Ontario International Airport flight is Rs9,127. A round-trip plane ticket is currently Rs18,253. Depending on the availability and when you book, these fares can change.
Don't leave things to the last moment. You're more likely to get cheap tickets from DEN to ONT if you book early. Airlines often have some amazing early bird discounts.
May is the cheapest month for flights from Denver International Airport to Ontario International Airport. If you're looking to travel during a different time of year, the 'Whole month' tool will show you the lowest airfares for every month.
You don't need to check back in every day to find out if fares have gone down when you set up a Price Alert. We'll let you know as soon as there's a new deal on cheap flights from DEN to ONT.
Find the right flight for you by using the filters. To see the 'Fastest,' 'Best' or 'Cheapest' flights from Denver International Airport to Ontario International Airport, use the 'Sort by' tool. You can also filter by airline, arrival and departure times, and journey duration.

Handy information about Denver International Airport (DEN)

DEN is located at 8500 Pena Boulevard.
Denver International Airport gets top marks for its on-time performance. 80% of flights that depart DEN arrive at their destination without delay.
Denver International Airport is about 40 kilometres from central Denver. If you're ride-sharing, catching a taxi or driving from the centre, it'll take 35 minutes or so to arrive, depending on the traffic.
You can expect a trip time of roughly 35 minutes when using public transport.
Get your flight from Denver International Airport to Ontario International Airport off to a stress-free start. Just a quick drive from DEN, stay at Baymont by Wyndham Denver International Airport and be well-rested for the trip ahead.

Arriving at Ontario International Airport (ONT)

Consider staying in a hotel near ONT if you're on a late Denver International Airport to Ontario International Airport flight. Select one of these accommodation options and avoid the hassle of a long transfer:
Grab a Ontario International Airport rental car and explore Ontario and beyond with your own wheels. Dollar, Fox - Rent A Car and Thrifty are top outlets to choose from here.
For the lowest price, reserve your ride from Ontario International Airport around three weeks before your trip.

When to fly to Ontario International Airport (ONT)

July is the most popular month for flights from Denver International Airport to Ontario International Airport. For smaller crowds, travel to Ontario in March.
Book your flight from Denver International Airport to Ontario International Airport for August if you want to visit Ontario during its warmest month. You can expect temperatures of between 16ºC and 36ºC.
February has average temperatures of between 4ºC and 24ºC. Search for cheap tickets from DEN to ONT sometime around then if you want to travel when it's cooler.

Explore more of the United States

Los Angeles is just one of the many places in the United States waiting to be explored after you've experienced Ontario. Around 56 kilometres away to the west, top sights here include Hollywood Sign, Universal Studios Hollywood and Hollywood Bowl.
Around 153 kilometres south of Ontario, San Diego is another favourite stop in the United States. Get a taste of what this destination has to offer at San Diego Zoo, San Diego Balboa Park and USS Midway Museum.