Cheap flights from Ontario to Washington

One-way fares from $139 · ONT → WAS · prices found by travellers in the last 48 hours

Compare all dates Washington → Ontario
Cheapest fare
$139

Frontier Airlines · Sat, Dec 19

Cheapest month
December

from $139

Direct flights
Not recently

Usually 1+ stop

Quickest trip
5h 31m

3,640 km

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Cheapest month to fly from Ontario to Washington

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

  1. November 2026 $144
  2. December 2026 Cheapest $139
  3. April 2027 $207
  4. July 2027 $267
  5. September 2027 $1,509

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

Where to stay

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Things to do

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Getting around

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About flights from Ontario to Washington

Ontario (ONT) and Washington (WAS) are about 3,640 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 5h 31m. Over the next few months, one-way fares start from $139, 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 Ontario to Washington?

The cheapest one-way fare we've seen recently is $139 with Frontier Airlines, departing Saturday, December 19, 2026. Over the coming months, the lowest fare in each month ranges from $139 to $1,509.

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

December 2026 currently has the lowest fares, from $139 one way.

Are there direct flights from Ontario to Washington?

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

How long is the flight from Ontario to Washington?

The quickest journey we've seen takes about 5h 31m. Ontario and Washington are around 3,640 km apart.

Which airlines fly from Ontario to Washington?

Recent fares on this route were with Frontier Airlines, Southwest Airlines, American Airlines and United Airlines.

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