Cheap flights from Seattle to Ontario from C$ 111
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 14/6. 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.
Save money when you book flights with momondo
Big names, great deals
Big names, great deals
Search 100s of travel sites to compare prices.Filter for what you want
Filter for what you want
Free Wi-Fi? Early arrival? Instantly customize your resultsTrusted 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
United Airlines flights from Seattle to Ontario
Our best United Airlines deals on Seattle to Ontario flight tickets
Delta flights from Seattle to Ontario
Our best Delta 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?
The month of September is, on average, the cheapest month to fly to Ontario from Seattle, with most prices found around C$ 183. The month of August is another great option to travel to Ontario, with average flight prices from Seattle averaging around C$ 229.
What is the cheapest day to depart on your flight to Ontario?
On average, the least expensive day to fly to Ontario from Seattle is on a Saturday. momondo users have found tickets for Saturday departures for as low as C$ 137. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Monday is the most expensive day to depart from Seattle because it is more convenient for both business and leisure travellers. As a result, prices tend to be around C$ 312.
What is the cheapest time of day to depart on your flight to Ontario?
Our data shows that the cheapest Seattle to Ontario flights are usually those with departure times at noon. Our users have found flights to Ontario at noon for as low as C$ 138. Try not to purchase tickets in the evening because they tend to be around C$ 258. Of course, these prices can vary depending on the time of year and what airport you fly to.
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 C$ 270 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 C$ 209 on momondo.
What cabin class options are available on Seattle/Tacoma Intl to Ontario flights?
There are 1 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?
Alaska Airlines, United Airlines, and Hawaiian Airlines are the most popular carriers operating from Seattle/Tacoma Intl to Ontario
Which airlines fly to Ontario?
Alaska Airlines, Frontier and Spirit Airlines 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 35% of people opting to fly with this airline when travelling to Ontario. Keep in mind that there are 6 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 April 2025, 12 flights take off from Seattle and land in Ontario each day. The most common flight departure time for this route is 7:00p.m., with 42% 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 90 per week as of April 2025. The most frequent departure day is Thu, with 20% 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?
A flight from Seattle/Tacoma Intl to Ontario will travel around 1555.6 km. Flights usually cover this in 2h 31m, depending on flying conditions and air traffic around both airports.
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 refresh daily.
How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Ontario Airport?
As of April 2025, there are 2 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?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, 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 flights between Seattle and Ontario, the leading plane model is Airbus A320neo, making up 24.82% of the total bookings. Other popular models include Boeing 737-800 Passenger/BBJ2 (winglets) with 13.87%, Boeing 737-900 Passenger/BBJ3 (winglets) with 12.89%, and Boeing 737-900 with 9.63%.
What is the most popular airline from Seattle to Ontario?
Based on momondo bookings for flights between Seattle and Ontario, the leading airline is Frontier, making up 81% of the total bookings. Other popular airlines include Alaska Airlines with 19%.
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 C$ 81 | Free Cancellation | Rating 5.9 3,277 reviews | |||
| PriceFrom C$ 152 | Free Cancellation | Rating 8.0 9,851 reviews |
Alaska Airlines Flights From Seattle to Ontario
Across 15 Alaska Airlines flights from Seattle to Ontario this week, the average price was C$ 220, with the best Alaska Airlines deals starting from C$ 108 round-trip. 9,851 users have rated Alaska Airlines on momondo, with an average score of 8.0/10.
Frontier Flights From Seattle to Ontario
Frontier (5.9/10 from 3,277 reviews) operates around 4 flights from Seattle to Ontario in any given week. The average Frontier airfare for this route is around C$ 107, with deals from around C$ 58 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?
To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Ontario from Seattle.
Can I find flights from Seattle to Ontario with flexible booking policies on momondo?
momondo does allow users to show only those flights to Ontario from Seattle which offer a flexible booking policy as well as other useful filters and features.
How can momondo help me find flights from Seattle to Ontario?
momondo provides multiple filters to help you find the best flight to Ontario from Seattle. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.
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.