$98 Cheap Flights from Seattle (SEA) to Ontario Intl. Airport (ONT)
Popular airlines from Seattle-Tacoma International Airport (SEA) to Ontario Intl. Airport (ONT)
Alaska AirlinesAlaska Airlines
UnitedUnited
DeltaDelta
Frontier AirlinesFrontier Airlines
Southwest AirlinesSouthwest Airlines
American AirlinesAmerican Airlines
Cheap Flights from Seattle to Ontario (SEA-ONT)
Alternative airports near Ontario
Prices were available within the past 7 days. Prices and availability are subject to change.
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December is typically the cheapest month to flyDecember is typically the cheapest month to fly
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Seattle (SEA) to Ontario (ONT) at a glance
Travel between Seattle (SEA) and Ontario (ONT) with a selection of airlines on this domestic short-haul route. You can compare Seattle to Ontario flights, choosing from both full-service and low-cost carriers to discover the best options that align with your budget and schedule. Whether you're seeking cheap fares from Seattle or convenient weekly flights, you’re sure to find an itinerary that suits your travel plans as you explore the attractions and neighborhoods of Ontario.
- Fastest flight duration: around 2h 45m non-stop
- Route distance: roughly 1,000 miles (1,610 km)
- Flights per week: around 50+ flights with multiple daily departures on average
- Typical fares (one-way): economy tickets often range from $60–$295, depending on seasonality and how far ahead you book
Flights from Seattle - Tacoma International Airport (SEA) to Los Angeles - Ontario International Airport (ONT)
Based on the latest traveler bookings, here are the top airlines favored for flights from Seattle to Ontario, particularly for non-stop and one-stop options. Common layover locations include Sacramento International Airport (SMF) with around a 50-minute stop, Harry Reid International Airport (LAS) with about a 1 hour and 30-minute layover, and Norman Y. Mineta San Jose International Airport (SJC) offering a 1 hour and 15-minute stop. These choices allow you to balance price, total travel time, and cabin class to create the ideal itinerary.
- Alaska Airlines: As a comprehensive service provider, Alaska Airlines facilitates both non-stop and one-stop flights, with one-way ticket prices generally falling between $80 and $315. This airline handles about 44% of departures on this route, boasting a standard non-stop travel duration of 2 hours and 45 minutes.
- Delta: Delta serves as a full-service airline, offering both non-stop and one-stop travel options. One-way fares typically range from $70 to $340, making up roughly 37% of departures on this route, with a standard non-stop journey time of 2 hours and 45 minutes.
- Frontier Airlines: This budget airline provides both non-stop and one-stop services, with one-way fares usually between $60 and $200. Frontier Airlines accounts for around 8% of departures on this route, featuring a typical non-stop flight duration of 2 hours and 45 minutes.
- Southwest Airlines: A low-cost option, Southwest Airlines offers both non-stop and one-stop services, with one-way fares generally ranging from $75 to $300. This carrier represents about 7% of departures on this route, with a standard one-stop journey taking about 3 hours and 30 minutes in-flight and a total travel time of approximately 4 hours and 45 minutes.
- Hawaiian Airlines: As a full-service carrier, Hawaiian Airlines provides non-stop flights with one-way fares typically ranging from $90 to $295. This airline accounts for about 2% of departures on this route, ensuring a total journey time of 2 hours and 45 minutes.
Travelers flying from Seattle to Ontario have the option to enhance their journey by upgrading their flight. Delta provides first class and premium economy cabins, while Alaska Airlines features first class and business class options.
Best time to fly from Seattle (SEA) to Ontario (ONT)
The most popular months for travelers flying from Seattle to Ontario are February, March, and April, when peak temperatures in Ontario reach up to 62.6°F in April. If you prefer quieter travel, consider October, the least busy and relatively cheaper time to visit with fewer crowds and temperatures around 69.6°F. For better deals, May usually offers the lowest average one-way fare around $137. Flight availability peaks in July, with approximately 70 flights per week, making it easier to find convenient departure times. January and February have the fewest flights, with approximately 42 flights per week.
- Cheapest time to fly: May usually offers good deals with average one-way fare around $137, roughly 17% cheaper than the yearly average.
- Another budget-friendly time to fly: January typically offers an average one-way fare of around $147.
- Most flight options: July has the highest number of flights from Seattle to Ontario, with approximately 70 flights per week, giving you more flexibility in scheduling your trip.
| Month | Temperature | Demand | Weekly Flights | Average one-way Fare |
| January | 56.3°F (13.5°C) | Average | 42 | $147 |
| February | 56.7°F (13.7°C) | Slightly High | 42 | $173 |
| March | 59.0°F (15.0°C) | Slightly High | 45 | $161 |
| April | 62.6°F (17.0°C) | Slightly High | 53 | $182 |
| May | 65.3°F (18.5°C) | Average | 55 | $137 |
| June | 69.8°F (21.0°C) | Average | 64 | $154 |
| July | 74.3°F (23.5°C) | Average | 70 | $165 |
| August | 75.7°F (24.3°C) | Average | 66 | $160 |
| September | 75.0°F (23.9°C) | Slightly Low | 53 | $170 |
| October | 69.6°F (20.9°C) | Slightly Low | 55 | $169 |
| November | 62.6°F (17.0°C) | Slightly Low | 52 | $180 |
| December | 55.9°F (13.3°C) | Average | 54 | $192 |
*Average one-way fare is based on Expedia flight booking data from January 2025 to April 2026 for the specified route and travel class and may change depending on availability, dates, and demand.
Alternative route from Seattle (SEA) to Ontario (ONT)
- Seattle to Orange County (SEA-SNA): John Wayne Airport (SNA) is located approximately 31 miles from Los Angeles - Ontario International Airport (ONT). One-way fares in the economy class for this route generally fall between $70 and $340, influenced by the season and how far in advance you purchase your ticket. Both direct and connecting flights are commonly available. Major airlines serving this route include Alaska Airlines and Delta, with options for business and first class seating also offered.
How to find the best prices for flights from Seattle (SEA) to Ontario (ONT)
Getting some of the best deals on flights from Seattle to Ontario is all about timing and flexibility. Here are some key tips to help you save:
- Best times to book and fly: cheaper fares are often found when booking 2-8 weeks in advance, which aligns with when most travelers make their reservations. Departures in the afternoon, between 12 PM and 6 PM, tend to offer lower prices and are also the most popular times to fly. Additionally, flying on Thursday generally provides cheaper options, although Friday remains the most popular travel day.
- Set up price alerts: stay updated on price changes by using Expedia's Price Tracker. Receive alerts when fares drop for your selected route.
- Bundle and save: bundle your flight and hotel to save on Expedia, or unlock a hotel deal after booking your flight.*
- Compare flight options: use Expedia's search tool to compare airlines, routes, direct vs. non-direct flights, and flight times. You can also sort by price to find the most affordable options.
- Stay flexible with dates: being open to different travel days can sometimes help you find better prices on flights and hotels.
- Think about luggage: nowadays, it's important to check the airline's baggage policies to find the best value. That may be paying for an additional carry-on bag or booking a ticket with checked luggage included. Either way, double-check your allowance before confirming your booking to avoid excess baggage fees at the airport.
*Members only. Savings vary and are not available on all bundles. Select hotels.
Arriving at Los Angeles - Ontario International Airport from Seattle - Tacoma International Airport
Ontario welcomes travelers from Seattle with a range of transport options based on price, convenience, and proximity. For departures, Seattle - Tacoma International Airport is roughly a 20-minute drive (covering about 14 miles) from central Seattle. Here's how to reach Ontario efficiently:
- Hotel transfer: Transfers offer a convenient way to reach your hotel in Ontario, with options including free hotel shuttles and private rides, which can be arranged in advance with your hotel.
- Car rental: Renting a car from Los Angeles - Ontario International Airport is a great option if you plan to explore and sightsee beyond the city. Browse cheap car rentals at Los Angeles - Ontario International Airport on Expedia.
- Taxi/ride-hailing: Taxis and ride-hailing services may be available from designated pickup areas outside the terminal, check locally on arrival.
- Public transportation: From Los Angeles - Ontario International Airport, Panama City Seaport, a seaport, is located about 1.6 miles away by car, while Rancho Cucamonga Station, a train station, is approximately 3.7 miles from the airport, both easily accessible by vehicle.
Seattle to Ontario Intl. Airport Flights
The cheapest times to fly from Seattle to Ontario Intl. Airport
On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Seattle to Ontario Intl. Airport are during the month of February. You can find some of the cheapest flights from Seattle to Ontario Intl. Airport with Expedia's search tool and vast selection of airlines.
The best time to book a flight from Seattle to Ontario Intl. Airport
Sunday is one of the best days to book for cheap flights from Seattle to Ontario Intl. Airport: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.
How to find cheap round-trip tickets from Seattle to Ontario Intl. Airport
Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Seattle to Ontario Intl. Airport in 2026. You can also book with separate airlines for your outbound and return journeys, from $98 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.
Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Seattle to Ontario Intl. Airport flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.
You could also save big by booking one of Expedia's vacation packages. Bundling together your Seattle to Ontario Intl. Airport airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.
*Terms apply.
Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.
Frequently Asked Questions
How much does a flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) cost?
You can find cheap one-way flights from $98 and cheap return flights $198 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) with Expedia. One-way flights generally range between $91 and $764, and roundtrip flights usually range from $229 to $934. 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 Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) ticket fares go up or down.
*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
January is the cheapest month to fly from Seattle, WA to Ontario, CA, with average round-trip fares around $250. This price is about 16% lower than the average fare for the year, as demand tends to drop after the holiday season. Other economical months to consider are February and September.
*Averages based on flights available on Expedia in the last year.
Which airlines fly direct from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Choose from 2 airlines operating direct flights from SEA to ONT:
- Delta operates around 24 direct flights from SEA to ONT every week
- Hawaiian Airlines operates around 17 direct flights from SEA to ONT every week
What is the cheapest airline that flies from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Delta is one of the cheapest airlines offering nonstop flights from Seattle - Tacoma Intl. (SEA) to Ontario, CA (ONT), with round-trip tickets starting from around $419. 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.
*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
To find a cheap flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.), 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.
What is the best airline to fly with from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The best airline to fly with from Seattle, WA (SEA) to Ontario, CA (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, Frontier Airlines typically offers the lowest fares. WN offers the most daily flights from SEA to 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.
What is the best time to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
When flying from Seattle (SEA) to Ontario (ONT), January and September are ideal months. In January, you can find return flights for about $250, which is quite economical. September is also a popular choice, offering good weather and plenty of flight options. These months are great for balancing cost and convenience, based on booking data from the past year.
*Prices based on flights available on Expedia in the last year.
How many flights per day from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
There are approximately 4 nonstop flights per day from Seattle - Tacoma Intl. (SEA) to Los Angeles - Ontario Intl. (ONT). For more options, look at flights that include layovers.
What is the earliest flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The earliest flight from Seattle - Tacoma International (SEA) to Los Angeles - Ontario International (ONT) typically departs at around 12:15 AM, operated by American Airlines. This seasonal service is active in March, and an early departure allows you to make the most of your time in Ontario. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
The most popular departure times for flights from Seattle (SEA) to Ontario (ONT) are in the morning, from 6am to 9am. About 26% of passengers prefer this time window. Many major carriers, including Southwest Airlines, Alaska Airlines, and Delta offer flights during this window. This timing works well because it allows you to arrive in Ontario with a full day ahead of you.
How long does it take to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
Flying nonstop from SEA to ONT takes around 2 hours 50 minutes, with the route covering approximately 957 miles. Flights with a layover typically take 2 hours 10 minutes longer than direct options. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
You can fly first class between SEA and ONT. First class cabins are available on:
- American Airlines
- Delta Air Lines
- United Airlines
- Hawaiian Airlines
How much is a business class flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
A direct, return business class ticket from Seattle (SEA) to Ontario (ONT) typically costs between $731 - $1,061. A non-stop, one-way business class flight is usually around $405 - $726. Prices often fluctuate based on seasonality and how early you book. You may also be able to find a cheaper business class journey between Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) if you opt for a connecting flight.
*Prices based on flights available on Expedia in the last year.
How do I earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight with Expedia?
It's easy to earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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.
What airports do you fly into for Ontario from Seattle - Tacoma Intl. (SEA)?
If you're planning to travel to Ontario from Seattle - Tacoma Intl. (SEA), you can fly into Los Angeles - Ontario Intl. (ONT) Some flights may connect through major hubs like Denver Intl. (DEN), Los Angeles Intl. (LAX), Sacramento Intl. (SMF) before reaching Ontario. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) at the last minute?
Typically, booking a last minute flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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.
Is it cheaper to book a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) flight and hotel package?
Securing a Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) Los Angeles Vacation Packages 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.
Can I cancel or change the date of my flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.)?
If you booked your Seattle, WA (SEA-Seattle - Tacoma Intl.) to Ontario, CA (ONT-Los Angeles - Ontario Intl.) 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.
Travel information
Origin airport | Seattle-Tacoma International Airport |
|---|---|
Destination airport | Ontario Intl. Airport |
Distance | 956 miles away |
Airlines serving | Alaska Airlines, United, Delta, Frontier Airlines, Southwest Airlines, American Airlines |
Popular airline | Alaska Airlines |
Roundtrip price | $198 |
Average flight time | 2 hours 46 mins |