Cheap flight from Ontario to Seattle from $44
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Flights from Ontario to Seattle
Cheap flight deals from Ontario to Seattle
We've found these cheap flights for you. You can book one-way or round-trip flight tickets.
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Round-trip
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One way
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Cheapest nonstop
ONT 11:33 AM2h 47mNonstopSEA 2:20 PMOntario - Seattle | Tue, Jun 3 | Frontier Airlines
SEA 1:50 PM2h 40mNonstopSIN 4:30 PMSeattle - Ontario | Wed, Jun 4 | Frontier Airlines$71 $14952% OFF52% OFF$149 $71 -
ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Mon, Jun 2 | Frontier Airlines
SEA 1:50 PM2h 40mNonstopSIN 4:30 PMSeattle - Ontario | Wed, Jun 4 | Frontier Airlines$76 $14949% OFF49% OFF$149 $76
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ONT 10:03 AM3hNonstopSEA 1:03 PMOntario - Seattle | Sat, May 31 | Frontier Airlines
SEA 10:49 AM2h 49mNonstopSIN 1:38 PMSeattle - Ontario | Mon, Jun 2 | Frontier Airlines$77 $14948% OFF48% OFF$149 $77
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Thu, Jun 5 | Frontier Airlines
SEA 1:50 PM2h 40mNonstopSIN 4:30 PMSeattle - Ontario | Sat, Jun 7 | Frontier Airlines$7848% OFF$149 $78
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ONT 11:33 AM2h 47mNonstopSEA 2:20 PMOntario - Seattle | Tue, Jun 10 | Frontier Airlines
SEA 1:50 PM2h 40mNonstopSIN 4:30 PMSeattle - Ontario | Tue, Jun 17 | Frontier Airlines$8543% OFF$149 $85
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ONT 11:35 AM3h 1mNonstopSEA 2:36 PMOntario - Seattle | Tue, May 27 | Frontier Airlines
SEA 10:49 AM2h 45mNonstopSIN 1:34 PMSeattle - Ontario | Wed, May 28 | Frontier Airlines$8642% OFF$149 $86
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Sat, Jun 7 | Frontier Airlines
SEA 3:10 PM2h 42mNonstopSIN 5:52 PMSeattle - Ontario | Tue, Jun 10 | Frontier Airlines$8642% OFF$149 $86
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Wed, Jun 4 | Frontier Airlines
SEA 1:50 PM2h 40mNonstopSIN 4:30 PMSeattle - Ontario | Sat, Jun 7 | Frontier Airlines$8841% OFF$149 $88
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ONT 10:03 AM3hNonstopSEA 1:03 PMOntario - Seattle | Wed, May 28 | Frontier Airlines
SEA 1:50 PM2h 40mNonstopSIN 4:30 PMSeattle - Ontario | Wed, Jun 4 | Frontier Airlines$9735% OFF$149 $97
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ONT 10:05 AM3hNonstopSEA 1:05 PMOntario - Seattle | Thu, May 29 | Frontier Airlines
SEA 10:49 AM2h 49mNonstopSIN 1:38 PMSeattle - Ontario | Mon, Jun 2 | Frontier Airlines$11026% OFF$149 $110
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ONT 1:00 PM17h 25m1 stopsSEA Invalid DateOntario - Seattle | Thu, May 15 | Normal Airline
SEA 3:00 PM6hNonstopONT 4:00 PMSeattle - Ontario | Sat, May 17 | Normal AirlineFind More FlightsFind More Flights
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Cheapest nonstop
ONT 11:33 AM2h 47mNonstopSEA 2:20 PMOntario - Seattle | Tue, Jun 3 | Frontier Airlines$44 $15772% OFF72% OFF$157 $44
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Wed, Jun 4 | Frontier Airlines$44 $15772% OFF72% OFF$157 $44
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Sat, Jun 7 | Frontier Airlines$46 $15771% OFF71% OFF$157 $46
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ONT 10:03 AM3hNonstopSEA 1:03 PMOntario - Seattle | Wed, May 28 | Frontier Airlines$5466% OFF$157 $54
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Thu, Jun 5 | Frontier Airlines$5466% OFF$157 $54
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ONT 10:03 AM3hNonstopSEA 1:03 PMOntario - Seattle | Sat, May 31 | Frontier Airlines$5565% OFF$157 $55
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ONT 10:03 AM2h 46mNonstopSEA 12:49 PMOntario - Seattle | Mon, Jun 2 | Frontier Airlines$5665% OFF$157 $56
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ONT 10:03 AM3hNonstopSEA 1:03 PMOntario - Seattle | Sat, May 24 | Frontier Airlines$8347% OFF$157 $83
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ONT 4:29 PM3h 3mNonstopSEA 7:32 PMOntario - Seattle | Mon, May 19 | Frontier Airlines$11626% OFF$157 $116
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ONT 10:05 AM3hNonstopSEA 1:05 PMOntario - Seattle | Thu, May 22 | Frontier Airlines$11626% OFF$157 $116
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ONT 1:00 PM17h 25m1 stopsSEA Invalid DateOntario - Seattle | Thu, May 15 | Normal AirlineFind More FlightsFind More Flights
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Crossed out prices are calculated based on the average price of the corresponding route on Trip.com.
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Displayed prices are calculated based on the cheapest average weekly prices of the corresponding route on Trip.com.
Frequently Asked Questions
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When are flight tickets from Ontario (ONT) to Seattle (SEA) the cheapest?
Airlines adjust prices for flights from Ontario to Seattle based on the departure date and time of your selection. By analyzing data from all airlines, we've discovered that on Trip.com, you can find the lowest flight prices on Tuesdays, Wednesdays, and Saturdays. -
How much do flights from Ontario (ONT) to Seattle (SEA) cost?
According to Trip.com's data, the lowest price is around $183.
How to find a cheap flight from Ontario to Seattle
Wait until the last minute and flight costs are often sky-high. Plan ahead, book the right way, and your savings can soar. We have loads of saving tips to help you find a cheap flight from Ontario to Seattle. Book your flights at the right time and save more.
Be flexible with your travel dates to get the cheapest Ontario to Seattle ticket.
Tap "Date" in the flight search bar to browse the calendar and find airfare from Ontario to Seattle for the next six months in 2025. If you're looking to fly within the next three months, the lowest fare is $44 for a one-way ticket on Tue, Jun 3.
Compare cheap Ontario to Seattle flight deals from hundreds of airlines.
Our powerful search system compares prices from over 500 airlines. So you can find the cheapest flights from Ontario to Seattle. The most affordable airline currently operating on this route is Frontier Airlines.
Set up a Price Alert to track fare drops.
Set up a Price Alert for your Ontario to Seattle route to track ticket prices effortlessly—no need to check manually every day.
Don't miss out on cheap Ontario to Seattle flight deals and promo codes.
Stay updated on the latest deals with Trip.com Deals and Promo Codes for cheap flights. Sign up for a free membership to unlock even more exclusive flight discounts.
Book early or wait unitl the last minute to fine the best fares.
It's always better to book early! Airlines typically release their lowest fares about a year before departure, so check as soon as flights become available. If you miss that window, you may still find great deals closer to your travel date.
Search for flights on the go.
For the best booking experience on the go, download Trip.com and search for cheap flights from Ontario to Seattle to access exclusive deals just for you.
Flight Info | Ontario to Seattle
| Cheapest one-way flight price | $43 |
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| Cheapest round-trip ticket price | $70 |
| Off-season for travel | March |
| Peak season for travel | February |
| Flight distance | 12,362.98 km |
| Popular airline | Alaska Airlines |
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