Cheap flights from Ontario to Denver from $38
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to Denver departing on 5/11. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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How to get the cheapest flight ticket from Ontario to Denver
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to Denver?
The cheapest month to fly to Denver from Ontario is in January. Flight prices, which tend to average around $98, are often lower during this time because this is during the off-season. If you don’t want to visit Denver in January, then you should wait until February to fly from Ontario, when ticket prices are also cheap, with an average price of $108.
What is the cheapest day to depart on your flight to Denver?
The cheapest day to depart on your flight to Denver is on a Saturday when prices can be found for as low as $226. This is often the case because there is less demand to fly during this day of the week. The most expensive day to fly to Denver is Sunday, with ticket prices averaging around $322.
What is the cheapest time of day to depart on your flight to Denver?
The cheapest time of day to fly to Denver is in the afternoon when flights can be purchased for as low as $224. Flights at noon are often more expensive with an average ticket price of $341.
What is the cheapest Ontario to Denver Intl flight route?
Fly from Ontario to Denver Intl for the best Ontario - Denver Intl flight prices
How far in advance should I book a flight to Denver?
You are more likely to see cheaper flights to Denver from Ontario when booking 6 weeks ahead of your departure date. In general, you can expect to find flights to Denver for around $143 when searching 6 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Denver from Ontario for as low as $106 on momondo.
What cabin class options are available on Ontario to Denver Intl flights?
There are 4 cabin classes available to choose from on Ontario to Denver Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
What is the cheapest airline that flies from Ontario to Denver Intl?
Frontier, Southwest, and United Airlines are the most popular carriers operating from Ontario to Denver Intl
What airlines fly to Denver?
Frontier, United Airlines and Southwest are the top three most popular airlines that fly to Denver from Ontario according to our data. Frontier is the first choice among our users, with 54% of people opting to fly with this airline when traveling to Denver. Keep in mind that there are 7 different airlines that fly to Denver on a routine basis, so you have a few additional options to choose from.
How many flights depart from Ontario to Denver on average per day?
The number of flights available between Ontario and Denver is 9 per day as of April 2025. The most frequent departure time is 5:00AM, with 46% of daily flights leaving in the morning.
How many flights depart from Ontario to Denver on average per week?
As of April 2025, 69 flights take off from Ontario and land in Denver each week. The most common flight departure day for this route is Mon, with 17% of weekly flights taking off on this day.
When to book flights from Ontario to Denver
Cheap Ontario to Denver (ONT to DEN) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Ontario to Denver
How far is Ontario to Denver Intl by plane?
The straight-line distance from Ontario to Denver Intl is 800.5 mi. A reasonable flight in good conditions will take 2h 11m.
When did momondo last update prices for flights from Ontario Airport to Denver Intl Airport?
Prices for flights from Ontario Airport to Denver Intl Airport were last updated today.
How many operators does momondo search for flights from Ontario Airport to Denver Intl Airport?
The number of operators available for flights from Ontario Airport to Denver Intl Airport is 4 as of April 2025.
How old do you have to be to fly from Ontario Airport to Denver Intl Airport?
The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to Denver Intl Airport.
What documentation or ID do you need to fly to Denver Intl Airport?
The travel and health documents required for your trip to Denver Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Denver Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular plane model from Ontario to Denver?
Based on momondo bookings for flights between Ontario and Denver, the leading plane model is Airbus A320neo, making up 15.96% of the total bookings. Other popular models include Boeing 737 MAX 8 with 11.95%, Boeing 737-800 with 9.72%, and Boeing 737-800 Passenger/BBJ2 (winglets) with 9.63%.
What is the most popular airline from Ontario to Denver?
Based on momondo bookings for this flight route, the most popular airline on flight routes from Ontario to Denver is Frontier (76% of total bookings). The next most popular airlines are United Airlines (17%), Southwest (6%), and Delta (1%).
Best airlines flying from Ontario to Denver
Compare and see reviews for airlines that fly from Ontario to Denver with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $54 | Free Cancellation | Rating 6.0 3,281 reviews | |||
| PriceFrom $97 | Free Cancellation | Rating 8.0 4,279 reviews | |||
| PriceFrom $132 | Free Cancellation | Rating 7.4 8,656 reviews | |||
| PriceFrom $159 | Free Cancellation | Rating 8.0 7,917 reviews |
Southwest Flights From Ontario to Denver
Southwest flies from Ontario to Denver around 20 times per week, with 4,279 momondo users rating the airline 8.0/10. The cheapest Southwest deal from Ontario to Denver in the last 72 hours was $97 (round-trip), much lower than the average airfare cost of $265 for Southwest flights on this route.
United Airlines Flights From Ontario to Denver
Another popular option for Ontario to Denver flights is United Airlines (7.4/10, 8,656 ratings). United Airlines flies from Ontario to Denver around 19 times per week, with deals starting from $132 round-trip and rising to an average price of around $282.
Traveling to a place near Denver?
Book flights to Denver if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Ontario to Denver?
Finding the right flight to Denver from Ontario is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Denver quick and easy, saving you time and money.
Can I find flights from Ontario to Denver with flexible booking policies on momondo?
Yes. momondo allows you to filter the results for Ontario to Denver flights to just show those with flexible booking policies.
How can momondo help me find flights from Ontario to Denver?
momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Ontario to Denver.
I’m not ready to book a flight from Ontario to Denver right now. Can momondo alert me if prices change?
If you are simply researching potential flights to Denver, momondo offers a useful price alert feature which will track prices for flights to Denver from Ontario and alert you when they change.