Cheap flights from Seattle to Ontario from $49
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Ontario departing on 4/21. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
Discover deals from 900+ travel sites with momondo.
Big names and deals
Big names and deals
Search 100s of travel sites to compare prices.Filter for what you want
Filter for what you want
Free Wi-Fi? Stopover? Instantly customize your results.Trusted and free
Trusted and free
We’re completely free to use - no hidden charges or fees.Price Alerts
Price Alerts
Not ready to book? to track prices.Find the cheapest flights from Seattle to Los Angeles
Cheap round-trip flights
Cheap one-way flights
Cheap last minute flights
Cheap direct flights
Frontier flights from Seattle to Ontario
Our best Frontier deals on Seattle to Ontario flight tickets
United Airlines flights from Seattle to Ontario
Our best United Airlines deals on Seattle to Ontario flight tickets
See travel insights to Los Angeles from
How to get the cheapest flight ticket from Seattle to Ontario
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 Ontario?
In general, September is the cheapest month to fly from Seattle to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $130. If you aren’t able to travel during the month of September, then book flights to Ontario from Seattle during August instead. Flights to Ontario in August, while not as cheap as those in September, still average around $157.
What is the cheapest day to depart on your flight to Ontario?
The cheapest day to depart on your flight to Ontario is on a Thursday when prices can be found for as low as $171. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to Ontario for around $211.
What is the cheapest time of day to depart on your flight to Ontario?
At noon is the cheapest time of day to fly from Seattle to Ontario when you can find flight prices for as low as $142. Flying to Ontario at noon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the morning when prices are $208 on average. Flights to Ontario from Seattle in the morning are generally more expensive because this time of day is more convenient for travelers’ schedules.
What is the cheapest Seattle/Tacoma Intl to Ontario flight route?
Fly from Seattle/Tacoma Intl to Ontario for the best Seattle/Tacoma Intl - Ontario flight prices
How far in advance should I book a flight to Ontario?
You are more likely to see cheaper flights to Ontario from Seattle when booking 11 weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $193 when searching 11 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Seattle for as low as $126 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to Ontario flights?
There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to Ontario 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 Seattle/Tacoma Intl to Ontario?
Frontier, United Airlines, and Delta are the most popular carriers operating from Seattle/Tacoma Intl to Ontario
What airlines fly to Ontario?
Alaska Airlines, Delta and Frontier are the top three most popular airlines that fly to Ontario from Seattle according to our data. Alaska Airlines is the first choice among our users, with 48% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 9 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.
How many flights depart from Seattle to Ontario on average per day?
As of March 2025, 11 flights take off from Seattle and land in Ontario each day. The most common flight departure time for this route is 1:00PM, with 46% of daily flights taking off in the afternoon.
How many flights depart from Seattle to Ontario on average per week?
The number of flights available between Seattle and Ontario is 81 per week as of March 2025. The most frequent departure day is Fri, with 23% of weekly flights leaving on this day.
When to book flights from Seattle to Ontario
Cheap Seattle to Ontario (SEA to ONT) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Seattle to Ontario
How far is Seattle/Tacoma Intl to Ontario by plane?
The distance between Seattle/Tacoma Intl and Ontario is about 966.6 mi. A reasonable flight in good conditions will take 2h 33m.
When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Ontario Airport?
Prices for flights from Seattle/Tacoma Intl Airport to Ontario Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Ontario Airport?
As of March 2025, there are 6 operators available to choose from for flights from Seattle/Tacoma Intl Airport to Ontario Airport.
How old do you have to be to fly from Seattle/Tacoma Intl Airport to Ontario 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 Seattle/Tacoma Intl Airport to Ontario Airport.
What documentation or ID do you need to fly to Ontario Airport?
The travel and health documents you'll need for your trip to Ontario Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Ontario Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Seattle to Ontario?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Seattle to Ontario is Airbus A320neo (25.23% of total bookings). The next most popular plane models are Boeing 737-800 Passenger/BBJ2 (winglets) (14.06%), Boeing 737-900 Passenger/BBJ3 (winglets) (12.02%), and Boeing 737-900 (9.78%).
What is the most popular airline from Seattle to Ontario?
momondo data reveals that the most frequently booked airline on the route from Seattle to Ontario is Frontier, representing 45% of all bookings. The subsequent popular airlines are Alaska Airlines at 31%, Delta at 21%, and Hawaiian Airlines at 1%.
Best airlines flying from Seattle to Ontario
Compare and see reviews for airlines that fly from Seattle to Ontario with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $40 | Free Cancellation | Rating 6.3 7,882 reviews | |||
| PriceFrom $56 | Free Cancellation | Rating 6.0 3,271 reviews | |||
| PriceFrom $95 | Free Cancellation | Rating 7.9 2,336 reviews | |||
| PriceFrom $117 | Free Cancellation | Rating 8.0 7,895 reviews | |||
| PriceFrom $136 | Free Cancellation | Rating 8.0 9,798 reviews | |||
| PriceFrom $196 | Free Cancellation | Rating 8.0 4,274 reviews |
Delta Flights From Seattle to Ontario
Delta flies from Seattle to Ontario around 11 times per week, with 7,895 momondo users rating the airline 8.0/10. The cheapest Delta deal from Seattle to Ontario in the last 72 hours was $117 (round-trip), much lower than the average airfare cost of $260 for Delta flights on this route.
Alaska Airlines Flights From Seattle to Ontario
Alaska Airlines (8.0/10 from 9,798 reviews) operates around 9 flights from Seattle to Ontario in any given week. The average Alaska Airlines airfare for this route is around $272, with deals from around $136 rare but found on momondo. Referenced prices are for round-trip Seattle to Ontario flight searches in the last 72 hours.
Why use momondo?
Why should I use momondo to find a flight deal from Seattle to Ontario?
We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Seattle to Ontario for you.
Can I find flights from Seattle to Ontario with flexible booking policies on momondo?
Yes. momondo allows you to filter the results for Seattle to Ontario flights to just show those with flexible booking policies.
How can momondo help me find flights from Seattle to Ontario?
momondo helps you find the best flight between Seattle and Ontario by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.
I’m not ready to book a flight from Seattle to Ontario right now. Can momondo alert me if prices change?
Price alerts on flights to Ontario from Seattle are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.