Cheap flights from Seattle to Ontario

One-way fares from $98 · SEA → ONT · prices found by travellers in the last 48 hours

Compare all dates Ontario → Seattle
Cheapest fare
$98

Frontier Airlines · Mon, Dec 7

Cheapest month
December

from $98

Direct flights
Not recently

Usually 1+ stop

Quickest trip
3h 53m

1,560 km

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Cheapest month to fly from Seattle to Ontario

Lowest one-way fare per person in each month. Choose a month to see every date.

  1. November 2026 $108
  2. December 2026 Cheapest $98
  3. January 2027 $130

Plan the rest of your trip to Ontario

Where to stay, what to do and getting around, from our travel partners.

Where to stay

Hotels in OntarioCompare places to stay on Booking.com Find hotels →

Things to do

Things to do in OntarioTours, attractions and day trips on Klook Explore →

Getting around

Airport transfer in OntarioPre-book a driver to meet you at arrivals, with Kiwitaxi Book a transfer → Car hire in OntarioCompare rental cars from major brands on EconomyBookings Compare cars →

About flights from Seattle to Ontario

Seattle (SEA) and Ontario (ONT) are about 1,560 km apart. We haven't seen direct fares on this route recently, so expect at least one stop; the quickest journey we've seen takes about 3h 53m. Over the next few months, one-way fares start from $98, and December 2026 is currently the cheapest month to fly.

These prices come from searches travellers made in the last 48 hours, so they move quickly. If you see a good fare, it's worth booking soon. FlightsExp is free to use: you book directly with our travel partner.

Frequently asked questions

How much is a flight from Seattle to Ontario?

The cheapest one-way fare we've seen recently is $98 with Frontier Airlines, departing Monday, December 7, 2026. Over the coming months, the lowest fare in each month ranges from $98 to $130.

What is the cheapest month to fly from Seattle to Ontario?

December 2026 currently has the lowest fares, from $98 one way.

Are there direct flights from Seattle to Ontario?

We haven't seen direct fares recently, so most journeys include at least one stop.

How long is the flight from Seattle to Ontario?

The quickest journey we've seen takes about 3h 53m. Seattle and Ontario are around 1,560 km apart.

Which airlines fly from Seattle to Ontario?

Recent fares on this route were with Frontier Airlines.

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