Cheap Flights from Seattle (SEA) to Ontario Intl. Airport (ONT)

You can find one-way and return flights from SEA to ONT with Expedia. 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 our cheapest fares first, and use the Price Tracking tool to receive alerts when SEA to ONT ticket fares go up or down.

January is typically the cheapest month to fly from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT), with average return fares around AU$373. January sees lower prices because it falls after the holiday travel rush, when demand drops and airlines compete for bookings. February and September are also good months to find deals on this route.

There are 2 airlines offering direct flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT). Here are the carriers:
* Delta operates 31 direct flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) every week.
* Frontier Airlines operates 7 direct flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) every week.

Mineta San Jose Intl. (SJC), starting from around AU$124. Airport (ONT), with tickets starting from around AU$421 for flights that can be booked for departure within the next year. Southwest Airlines is one of the cheapest airlines offering nonstop return flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Southwest Airlines also offers one of the cheapest connecting return flights on this route, with a layover in Norman Y. 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 Seattle, WA (SEA) 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 Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) will differ from traveler to traveler. If you like to fly early, Delta offers early morning flights. If price is the most important factor, Southwest Airlines typically offers the lowest fares. Southwest Airlines offers the most daily flights from Seattle - Tacoma Intl. (SEA) 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 best time to fly is usually mid-week (Tuesday or Wednesday) and during early morning hours as flights tend to be cheaper, less crowded, and generally more on-time. Avoid major holidays and peak vacation seasons for smoother travel. Combining off-peak days and hours often gives the best combination of cost, comfort, and convenience.

You'll find around 5 nonstop flights per day from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT). For even more choices, look at flights that include layovers, as there are approximately 70 connecting flights per day. Some common connection points include Denver Intl. (DEN), Portland Intl. (PDX), and Sky Harbor Intl. (PHX).

The earliest flight from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) typically departs around 12:25 AM. This flight is operated by American Airlines. This is a seasonal service, active only in September. An early departure like this can be great if you want to maximize your time at your destination. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.

You'll find the most flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) on a Friday, with around 63 flights available. This gives you a good selection of options for your travel plans. Major airlines on this route include Alaska Airlines, Southwest Airlines, and United. Flight options are notably more plentiful on Fridays compared to other days of the week, offering you more flexibility.

The most popular departure times for flights from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) are in the morning, from 6am to 9am. Many major carriers, including Alaska Airlines, Southwest Airlines and Delta, offer flights during this window. Many travellers prefer this because it allows for an early start to their journey, giving them more time at their destination.

A nonstop flight from Seattle - Tacoma Intl. (SEA) to Ontario Intl. Airport (ONT) typically takes around 2 hours 48 minutes. This route covers a distance of approximately 1540 kilometres. If you opt for a flight with one stop, your travel time will be longer, usually around 5 hours. Flights with two or more stops generally take about 11 hours 30 minutes. 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 extra time when planning your journey.

Yes, you can fly business class or first class between Seattle - Tacoma Intl. (SEA) and Ontario Intl. Airport (ONT).

Airlines that offer business class service on this route include:

* Frontier Airlines
* Alaska Airlines
* Delta

First class cabins are available on:

* Alaska Airlines
* Delta
* Hawaiian Airlines
* United
* American Airlines

It's easy to earn miles on a Seattle, WA (SEA) 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 Seattle - Tacoma Intl. (SEA), you can fly directly into Los Angeles - Ontario Intl. (ONT). Some flights may connect through major hubs like Denver Intl. (DEN), Los Angeles Intl. (LAX), or Harry Reid International Airport (LAS) 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 Seattle, WA (SEA) 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 Seattle, WA (SEA) 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 Seattle, WA (SEA) 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.