£110 Cheap Flights from Washington (IAD) to Ontario (ONT)

View £110 flight on Tue, 9 Dec 2025Opens in a new window

Popular airlines from Washington Dulles International Airport (IAD) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from Washington (IAD) to Ontario (ONT)

Prices were available within the past 7 days and start at £110 for one-way flights and £220 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Delta
Tue, 16 Sep - Wed, 17 Sep
IAD
Washington
ONT
Ontario
£220 Return, found 4 days ago
£220
Return
found 4 days ago
Select Delta flight, departing Tue, 16 Sep from Washington to Ontario, returning Wed, 17 Sep, priced at £220 found 4 days ago
Delta
Tue, 11 Nov - Thu, 27 Nov
IAD
Washington
ONT
Ontario
£228 Return, found 1 day ago
£228
Return
found 1 day ago
Select Delta flight, departing Tue, 11 Nov from Washington to Ontario, returning Thu, 27 Nov, priced at £228 found 1 day ago
American Airlines
Wed, 3 Sep - Wed, 24 Sep
IAD
Washington
ONT
Ontario
£232 Return, found 3 days ago
£232
Return
found 3 days ago
Select American Airlines flight, departing Wed, 3 Sep from Washington to Ontario, returning Wed, 24 Sep, priced at £232 found 3 days ago
Delta
Wed, 3 Sep - Fri, 12 Sep
IAD
Washington
ONT
Ontario
£243 Return, found 6 days ago
£243
Return
found 6 days ago
Select Delta flight, departing Wed, 3 Sep from Washington to Ontario, returning Fri, 12 Sep, priced at £243 found 6 days ago
American Airlines
Tue, 16 Sep - Wed, 17 Sep
IAD
Washington
ONT
Ontario
£252 Return, found 4 days ago
£252
Return
found 4 days ago
Select American Airlines flight, departing Tue, 16 Sep from Washington to Ontario, returning Wed, 17 Sep, priced at £252 found 4 days ago
Delta
Tue, 16 Sep - Wed, 17 Sep
IAD
Washington
ONT
Ontario
£296 Return, found 4 days ago
£296
Return
found 4 days ago
Select Delta flight, departing Tue, 16 Sep from Washington to Ontario, returning Wed, 17 Sep, priced at £296 found 4 days ago
United
Wed, 3 Sep - Wed, 24 Sep
IAD
Washington
ONT
Ontario
£306 Return, found 3 days ago
£306
Return
found 3 days ago
Select United flight, departing Wed, 3 Sep from Washington to Ontario, returning Wed, 24 Sep, priced at £306 found 3 days ago
American Airlines
Tue, 16 Sep - Wed, 17 Sep
IAD
Washington
ONT
Ontario
£326 Return, found 4 days ago
£326
Return
found 4 days ago
Select American Airlines flight, departing Tue, 16 Sep from Washington to Ontario, returning Wed, 17 Sep, priced at £326 found 4 days ago
Delta
Thu, 23 Oct - Thu, 6 Nov
IAD
Washington
ONT
Ontario
£345 Return, found 2 days ago
£345
Return
found 2 days ago
Select Delta flight, departing Thu, 23 Oct from Washington to Ontario, returning Thu, 6 Nov, priced at £345 found 2 days ago
Alaska Airlines
Mon, 1 Sep - Mon, 8 Sep
IAD
Washington
ONT
Ontario
£791 Return, found 1 day ago
£791
Return
found 1 day ago
Select Alaska Airlines flight, departing Mon, 1 Sep from Washington to Ontario, returning Mon, 8 Sep, priced at £791 found 1 day ago

Find the cheapest month to fly from Washington (IAD) to Ontario (ONT)

August is typically the cheapest month to fly

From £144 - £310 per traveller.

Graph displaying average flight prices per month

Flight from Washington to Ontario route information
Origin airport
Washington Dulles Intl.
Destination airport
Los Angeles - Ontario Intl.
Return price
£220
Distance
3578 km

Compare flights from Washington to Ontario easily and book with confidence

For travelling on business or for pleasure, Expedia makes it easy to book your flights from Washington to Ontario. Operating between them flights per day, 20 airlines cover the route. And fly direct, getting you to Los Angeles - Ontario Intl. in just hours. If you have a preferred carrier, use our advanced search tool to find the right flight from Washington Dulles Intl. to Los Angeles - Ontario Intl..  

To make things even better, in the advanced search, you can also choose to fly economy, premium economy, business or first class, select your maximum number of stops, and pick your preferred departure and arrival time. You can also opt for refundable and direct flights. 

Grab a great deal on your flight from Washington Dulles Intl. (IAD) to Los Angeles - Ontario Intl. (ONT)

The easiest way to view the best deals on flights from Washington to Ontario today is to enter your travel dates and hit search. From here, you can sort your results by price to see the cheapest flights first. Right now, return flights from Washington Dulles Intl. to Los Angeles - Ontario Intl. start at just £220 and range up to £791.  

To find an even better deal, try  

  • being flexible on your dates – midweek flights can be cheaper
  • looking for other airports near Washington and Ontario
  • booking your flight during September, the cheapest month on this route
  • varying your flight times – early morning and late at night are sometimes cheaper 

Why you should book your Washington to Ontario flight with Expedia!

We cater for all flight types, cabin classes and airlines. So whether you’re booking flights from Washington Dulles Intl. to Los Angeles - Ontario Intl. for a budget break or a business trip with a bit of pleasure thrown in, we make it easy to secure the seat that’s right for you.  

Thanks to our supersized inventory that offers great choice all in one place, you know you’ll get a great deal with Expedia. Especially if you bundle your flight together with your hotel, you will unlock amazing savings. For added peace of mind, you can choose flexible bookings or filter to find refundable options, so you won’t pay a fee to change your flight.  

Frequently asked questions

How much is a flight from Washington Dulles Intl. Airport (IAD) to Los Angeles - Ontario Intl. Airport (ONT)?
Within the past 7 days on Expedia, for flights departing within the next year, the lowest price quoted for a round-trip flight from Washington Dulles Intl. Airport (IAD) to Los Angeles - Ontario Intl. Airport (ONT) was £220. Cheap tickets don't last long, so make sure you book yours ASAP. Prices and availability are subject to change. Additional terms apply.
Do I need to pay a cancellation fee if I cancel my flight from IAD to ONT?
The majority of flights can be cancelled online, but each air carrier has different terms and conditions. If you do decide to cancel your flight, check out our Customer Service Portal and follow the instructions.
How do I find cheap flights from IAD to Los Angeles - Ontario Intl. Airport (ONT) that have flexible change policies?
Many airlines offer the option to reschedule your flight without a change fee. All you pay is the difference between the original flight and the new flight. When you're searching for IAD to ONT flights, you'll see a "no change fees" filter for you to select.
How far is the flight from IAD to Los Angeles - Ontario Intl. Airport (ONT)?
Expect to be in the air for a while, as the flight distance between Chantilly and Ontario is 3,600 kilometres. Create a playlist of your favourite songs before leaving home to keep yourself entertained during the trip.
Which airlines fly direct from Washington Dulles Intl. Airport (IAD) to Ontario Airport?
You won't find any airlines operating directly between Dulles Intl. Airport and Los Angeles - Ontario Intl. Airport (ONT), so be prepared to make at least one stop on your journey. A layover, whether short or long, can be a welcome way to break up a trip!
Are Dulles Intl. Airport to ONT flight tickets cheaper when they're purchased at the last minute?
Flight tickets from IAD to Los Angeles - Ontario Intl. Airport (ONT) are available up to a year prior to departure on Expedia. And although you may occasionally score a great last-minute deal, it's not something you should bank on. Also, booking your flights well in advance means you'll have more choices — and you can avoid ending up with the dreaded middle seat! We're constantly updating our fares to bring you the best bargains, so keep checking in for all the latest specials.

Explore a world of travel with Expedia

Ontario Airports

Orange County

Washington to Los Angeles Intl.
£154.58

Los Angeles

Washington to Los Angeles Intl.
£220.00

Burbank

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