CA $207 Cheap Flights from Denver (DEN) to Ontario Intl. Airport (ONT)

You can find cheap one-way flights from CA $207 and cheap return flights CA $409 DEN to ONT with Expedia. One-way flights typically cost between CA$786 and CA$1665. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when DEN to ONT ticket fares go up or down.

September is typically the cheapest month to fly from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT), with average return fares around CA$308. September often sees lower prices as the summer travel rush ends and before the holiday season begins, leading to reduced demand. Other cheap months to fly from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) include February and April.

You have 3 airlines offering direct flights from Denver Intl. (DEN) to Ontario Intl. Airport (ONT). Here are the carriers:
* Southwest Airlines operates 26 direct flights from Denver Intl. to Ontario Intl. Airport every week.
* United operates 16 direct flights from Denver Intl. to Ontario Intl. Airport every week.
* Frontier Airlines operates 14 direct flights from Denver Intl. to Ontario Intl. Airport every week.

Frontier Airlines is one of the cheapest airlines offering nonstop return flights from Denver Intl. (DEN) to Ontario Intl. Airport (ONT), with tickets starting from around CA$77 for flights that can be booked for departure within the next year. JetBlue Airways offers one of the cheapest connecting return flights from Denver Intl. (DEN) to Ontario Intl. Airport (ONT) starting from around CA$532. These prices are per adult for economy/coach class. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.

To find a cheap flight from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.

The best airline to fly with from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) will differ from traveler to traveler. If you like to fly early, Southwest Airlines offers early morning flights. If price is the most important factor, Frontier Airlines typically offers the lowest fares. Southwest Airlines offers the most daily flights from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT), which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.

The cheapest months to fly from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) are typically September and February, with average return flights around CA$308. The most popular months for this route are April and January, meaning you'll find plenty of flight options during these times. While there isn't a single month that is both the cheapest and most popular, you can balance cost and availability by considering September or February for better prices, or April and January for more flight choices.

You'll find approximately 8 nonstop flights per day from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT). For even more choices, look at flights that include layovers, as there are around 114 connecting flights per day. Some common connection points include Seattle - Tacoma Intl. (SEA), Harry Reid Intl. (LAS), and Portland Intl. (PDX).

The earliest flight from Denver International Airport (DEN) to Ontario International Airport (ONT) typically departs around 12:40 AM local time, operated by Delta. This is a seasonal service, active only in June. An early departure like this can help you make the most of your time at your destination. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.

You'll typically find the most flights from Denver International Airport (DEN) to Ontario International Airport (ONT) on a Friday, with around 89 flights available. This gives you plenty of options if you're planning a weekend getaway or a business trip. Major airlines on this route include Southwest Airlines, Frontier Airlines, and Alaska Airlines. Fridays offer notably more flight options compared to other days of the week, making it a popular choice for travellers.

The most popular departure times for flights from Denver Intl. (DEN) to Ontario Intl. Airport (ONT) are in the early morning, from 6am to 9am. Many major carriers, including Southwest Airlines, Frontier Airlines and Alaska Airlines, offer flights during this window. Many travellers prefer these early flights as they allow you to arrive at your destination with plenty of time to start your day.

A nonstop flight from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) typically takes around 2 hours 30 minutes. This route covers a distance of approximately 1,315 kilometers. If you opt for a one-stop flight, your travel time will be longer, usually around 7 hours. Flights with two or more stops can take even longer, often around 7 hours as well. Keep in mind that actual flight times can vary due to factors like wind patterns and air traffic, so it's always a good idea to allow for some flexibility in your travel plans.

You can fly business class or first class between DEN and ONT. You can fly business class with Frontier Airlines and Delta.

First class cabins are available on:

• Alaska Airlines
• Delta
• American Airlines
• United

It's easy to earn miles on a Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.

*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.

If you're planning to travel to Ontario from Denver Intl. (DEN), you can fly directly into Los Angeles - Ontario Intl. (ONT) which offers international flights and connections. Some flights may connect through major hubs like Seattle - Tacoma Intl. (SEA), San Diego Intl. (SAN), or Portland Intl. (PDX) before reaching Ontario. Compare routes and airports on Expedia to find the best flight options for your travel plans.

Typically, booking a last minute flight from Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.

Securing a Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.

If you booked your Denver, CO (DEN-Denver Intl.) to Ontario Intl. Airport (ONT) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more information.