Find flights
Deals
Insights
When to book
FAQs & Tips
Airlines

IAD - ONT

$147 Find Cheap Flights from Washington Dulles Airport to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Dulles Intl to Ontario departing on 11/12. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
0 bags

Search hundreds of travel sites at once for deals on flights to Ontario

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Ontario, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to Ontario, as well as popular online travel agencies
In the last 7 days travelers have searched 45,114,312 times on KAYAK, and here is why:

Save 22% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Bundle and saveSave money when you bundle your flight + hotel.

World’s Best Airfare Search Site for 2024

Cheap Flight Deals from Washington Dulles Airport to Ontario (IAD-ONT)

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Washington Dulles Airport to Ontario that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
8:20 am - 5:35 pmIAD-ONT
12h 15m1 stop
4:15 pm - 7:01 amONT-IAD
11h 46m1 stop
$296Alaska Airlines
Find Deal
Thu, Oct 31 - Tue, Nov 5
6:30 pm - 10:49 pmIAD-ONT
7h 19m1 stop
10:00 pm - 9:04 amONT-IAD
8h 04m1 stop
$297Delta
Find Deal
Sat, Nov 2 - Fri, Nov 15
6:00 am - 10:28 amIAD-ONT
7h 28m1 stop
7:04 am - 11:03 pmONT-IAD
12h 59m2 stops
$301Delta
Find Deal
Thu, Oct 31 - Tue, Nov 5
6:57 pm - 3:11 pmIAD-ONT
23h 14m1 stop
6:00 am - 5:52 pmONT-IAD
8h 52m1 stop
$319Alaska Airlines
Find Deal
Wed, Jan 29 - Fri, Feb 7
2:50 pm - 11:35 pmIAD-ONT
11h 45m2 stops
5:30 am - 7:00 pmONT-IAD
10h 30m1 stop
$332Southwest
Find Deal
Fri, Nov 15 - Sun, Nov 17
1:49 pm - 8:55 pmIAD-ONT
10h 06m1 stop
7:40 pm - 8:43 amONT-IAD
10h 03m2 stops
$336American Airlines
Find Deal
Wed, Oct 23 - Sat, Oct 26
1:47 pm - 10:03 pmIAD-ONT
11h 16m2 stops
7:30 pm - 10:29 amONT-IAD
11h 59m2 stops
$341American Airlines
Find Deal
Thu, Nov 14 - Mon, Nov 18
2:05 pm - 11:25 pmIAD-ONT
12h 20m2 stops
8:55 am - 7:00 pmONT-IAD
7h 05m1 stop
$433Southwest
Find Deal
Fri, Oct 18 - Sat, Oct 26
6:30 am - 12:40 pmIAD-ONT
9h 10m1 stop
6:30 pm - 5:11 amONT-IAD
7h 41m1 stop
$462United Airlines
Find Deal
Wed, Dec 25 - Wed, Jan 1
8:35 am - 5:17 pmIAD-ONT
11h 42m1 stop
6:20 pm - 5:24 amONT-IAD
8h 04m1 stop
$500United Airlines
Find Deal
Tue, Oct 8 - Tue, Oct 15

Flights from Dulles Intl to Ontario - Travel Insights & Trends

Get data-powered insights and trends into flights from Dulles Intl to Ontario to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Washington Dulles Airport to Ontario?

The average price of all flights from Washington, D.C. Dulles Intl Airport to Ontario clicked on KAYAK for each day over the last 12 months.
For Washington Dulles Airport to Ontario, Thursday is the cheapest day to fly on average and Monday is the most expensive. Flying from Ontario back to Washington Dulles Airport, the best deals are generally found on Thursday, with Sunday being the most expensive.

What is the cheapest month to fly from Washington, D.C. Dulles Intl Airport to Ontario?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights from Washington, D.C. Dulles Intl Airport to Ontario, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.
The cheapest month for flights from Washington, D.C. Dulles Intl Airport to Ontario is January, where tickets cost $264 on average. On the other hand, the most expensive months are June and November, where the average cost of tickets is $486 and $426 respectively.

How far in advance should I book a flight from Washington, D.C. Dulles Intl Airport to Ontario?

To calculate daily average prices, KAYAK takes all prices for each day before departure over the last year for flights from Washington, D.C. Dulles Intl Airport to Ontario, removes the top 0.1% to account for outliers, and then takes the average of all the values for each month.
To get a below average price on the flight from Washington, D.C. Dulles Intl Airport to Ontario, you should book around 1 day before departure. For the absolute cheapest price, our data suggests you should book 77 days before departure.

Good to know

Low season

February

High season

July

Cheapest flight

$147
Best time to beat the crowds with an average 30% drop in price.
Most popular time to fly with an average 1% increase in price.
Flight from Washington Dulles Airport to Ontario

When to book flights from Dulles Intl to Ontario

Are your dates flexible? Find out the best times to travel from Dulles Intl to Ontario based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking Washington Dulles Airport to Ontario flights

  • What is the cheapest flight from Washington, D.C. Dulles Intl Airport to Ontario?

    In the last 3 days, the lowest price for a flight from Washington, D.C. Dulles Intl Airport to Ontario was $147 for a one-way ticket and $296 for a round-trip.

  • Do I need a passport to fly between Washington Dulles Airport and Ontario?

    No, a passport isn't needed to fly from Washington Dulles Airport to Ontario. However, local authorities might ask for an official ID.

  • Which airports will I be using when flying from Washington Dulles Airport to Ontario?

    Washington Dulles Airport and Ontario are both served by 1 main airport. You will leave Washington Dulles Airport from Washington, D.C. Dulles Intl and will be arriving at Ontario.

  • Which aircraft models fly most regularly from Washington Dulles Airport to Ontario?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Washington Dulles Airport to Ontario?

    oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between Washington Dulles Airport and Ontario, with oneworld being the most commonly used for this route.

  • Which is the best airline for flights from Washington, D.C. to Ontario, Delta or United Airlines?

    The two airlines most popular with KAYAK users for flights from Washington, D.C. to Ontario are Delta and United Airlines. With an average price for the route of $375 and an overall rating of 8.0, Delta is the most popular choice. United Airlines is also a great choice for the route, with an average price of $492 and an overall rating of 7.4.

  • How does KAYAK find such low prices on flights from Washington Dulles Airport to Ontario?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Washington Dulles Airport to Ontario.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington Dulles Airport to Ontario?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from Washington Dulles Airport is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Washington Dulles Airport to Ontario?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Ontario with an airline and back to Washington Dulles Airport with another airline. Booking your flights between Washington Dulles Airport and ONT can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington Dulles Airport to Ontario?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Ontario from Washington Dulles Airport up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Top 3 airlines serving from Dulles Intl to Ontario

 
See real verified KAYAK customer reviews for airlines flying from Washington, D.C. to Ontario. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Dulles Intl to Ontario? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
DeltaOverall score based on 9062 reviews
8.6Crew
7.4Food
8.2Boarding
8.0Entertainment
7.9Comfort
Airline reviews

AC barely worked on a 50 minute flight. It was very warm the whole flight. Flight was very bumpy and hard landing.

2.0 MediocreSam, Aug 2024LAS - LAX
Read more Delta reviews

AC barely worked on a 50 minute flight. It was very warm the whole flight. Flight was very bumpy and hard landing.

Got on the plane and then needed to deboard the plane because they didn’t have any pilots?

The flight was canceled two hours before departure, it took over five hours to rebook us on another flight.

Rough day of travel all the way around. Wrong info given to us multiple times and mistakes in their booking making our trip 10 hours longer than planned. I’m bummed because I fly Delta all the time and love them. Mistakes happen. Just bummed that this was a rare trip our whole family was traveling together.

Meh. A late flight meant I missed my connections, and a 2pm LAX arrival turned into gettin in after midnight.

It was good until there was a 3 hour delay because there was not any pilots to fly the plane.

Had to change aircraft due to a faulty door. Surprisingly it only caused about an hour and a half of delay. Delta handled this situation as well as can be expected.

Your crew could maybe answer the call bell at least one of the times I pressed it. I pressed it first time with 2.5 hours left in our flight bc my partner was hungry and wanted a sandwich. We finally got the sandwich with 40 mins left in the flight.

The Flight crew didn’t serve us until about 1.5 hours into the flight because of turbulence but after it ended it was fine to move around. They served us water only and snacks and then NEVER, NOT ONE TIME came through to collect trash until right before landing about 1.5 hours later. There was absolutely no need for that. They crew was just standing around talking and visiting with each other and really never tried to see if we might want something besides water or even try to come pick up trash. This is VERY unusual for a Delta flight but it was not what I would have expected for a 4 hour flight.

There was a loud squeaky sound the whole time we were flying.

The Economy Plus rows weren’t as roomy as expected, and the meal service left a lot to be desired for.

United ground crew and pilots are friendly. The in-flight staff (flight attendants) are the worst in the world. Multiple trips, always unpleasant, combative, use implicit threats to not allow for a discussion on their decision. Authoritarian. This seems to stem from an internal corporate wide policy as I doubt that United is intentionally searching for people that are not fit for customer facing positions. I will not fly United again. Good luck fixing your business

The flight was mostly on time, smooth and deplaning was quick. Baggage was really quick at the claim. Comfort was so-so and I paid for economy plus. It was still too crowded and why was a family of 5 scattered all around the plane?

We boarded and buckled and then deplaned due to no pilot. Had to wait over 3 hours for a new pilot. Not weather related, just poor management.

Flying to anchorage would have been cool but the weather got in the way

Extremely uncomfortable sitting in a small space for 2 hours, especially for older people. Understood it was circumstantial.

Shout out to the check in counter staff in Richmond. So pleasant and helpful with ticketing and seat selection.

Brutal delay of 24 hours on first floight the 3 hours in Chicago . Tiny seats , screaming child behind me kicking the seat … couldn’t be worse

It got us to our destinations pretty well but the flight from Dulles to Newark was the size of a school bus or less and the flight to Israel was better but premium seats are way tooo expensive and necessary. The seat cushions in economy plus are virtually nonexistent. The service was minimal. There was a noticeable absence of beverage service, including nonalcoholic beverages. The flight to Israel was my mos on time flight to Israel ever. The pilot talked too much, though, especially yelling instructions at everyone.

UK Based crew was great. Very friendly and quick. The seats are just too tight and not comfortable. The plane appeared quite old. Food is better on other non-USA based airlines.

On time, smooth, luggage was out fast at the end of the flight. About perfect.

Flight departed on time and arrived a bit early. Can’t go wrong with that! And makes a travel experience go so well

WiFi wasn’t working on the flight, several delays and gate changes, ended up taking off 3 hrs later

delayed multiple times. no resolution on anything from AA customer service. was put on hold in chat to talk to manager. was 6th in line to talk to manager for more than TWELVE HOURS - from sometime around 9AM until well after I had gone to bed that evening. no explanation, no attempt to make it right. just a five hour delay because of repeated maintenance claims

Gate check in of luggage was smooth at DCA and luggage came out fast in IND.

This is by far the worst experience I have had with American Airlines. The start of this trip was a complete disaster. I purposely planned my trip so that I would weather any delays so that I could make very important meeting at the Pentagon. My flight was cancelled because of maintenance and I was put on the first flight the next day but I was late to the meeting. After a long week at the Pentagon I just wanted to go home and my flight home which was early in the day was delayed. Eventually the flight was delayed until the next day. I was not authorized a hotel room because DCA was my point of origin. So I paid for a hotel out of pocket. The flight this morning was boarded then deplaned because the aircraft was hot. The flow of information was not happening in DCA and made it worse when the news was bad. I am going to take a break from American for my next few military flights. Hopefully whatever has been going on with American Airlines will be resolved.

AA1537 the AC was not working properly. It was very hot and uncomfortable.

Everything was great except for the wifi was junk. Crew was super friendly and helpful

Overall the flights pretty good. The snacks we’re good and they were plenty of them. Both boarding and deplaning went quickly.

Delayed abs delayed Gate crew giving poor info - we are definitely leaving at —- Ultimately to cancel flight after 4+ hours of delays Just cancel it earlier

Book cheap flights from Washington, D.C. to Ontario

Recent one-way flight deals

 
Only flying one-way? Below are some of the best one-way flight deals from Washington, D.C. to Ontario found on KAYAK in the last 72 hours.
11/12Tue
1 stopAlaska Airlines
11h 20mIAD-ONT
$147
10/31Thu
1 stopDelta
7h 28mIAD-ONT
$148
12/4Wed
1 stopAmerican Airlines
8h 47mIAD-ONT
$149
11/5Tue
2 stopsDelta
10h 50mIAD-ONT
$153
11/24Sun
1 stopAmerican Airlines
10h 43mIAD-ONT
$184
12/31Tue
1 stopUnited Airlines
7h 57mIAD-ONT
$224
12/6Fri
1 stopUnited Airlines
8h 58mIAD-ONT
$229
11/26Tue
2 stopsSouthwest
8h 50mIAD-ONT
$234
10/18Fri
1 stopSouthwest
7h 05mIAD-ONT
$259
11/25Mon
1 stopAvianca
21h 00mIAD-ONT
$495

Search by stops

Search by airline

Search by price

Last minute flights from Dulles Intl to Ontario

Last minute flight, train and bus deals

 
These last-minute flight deals are the cheapest flights found on KAYAK in the last 72 hours for flights from Washington, D.C. to Ontario that are departing in the next 10 days.
9/24Tue
multi-stopDelta
7h 39mIAD-ONT
11/2Sat
multi-stopDelta
7h 30mONT-IAD
$519
9/24Tue
multi-stopAlaska Airlines
11h 33mIAD-ONT
10/3Thu
multi-stopAlaska Airlines
9h 06mONT-IAD
$640
9/21Sat
multi-stopDelta
8h 09mIAD-ONT
10/3Thu
multi-stopDelta
7h 11mONT-IAD
$671
9/24Tue
multi-stopDelta
7h 06mIAD-ONT
9/26Thu
multi-stopDelta
7h 11mONT-IAD
$703
9/23Mon
multi-stopDelta
7h 54mIAD-ONT
10/30Wed
multi-stopDelta
7h 20mONT-IAD
$716
9/21Sat
multi-stopUnited Airlines
7h 08mIAD-ONT
9/25Wed
multi-stopUnited Airlines
7h 58mONT-IAD
$842
9/21Sat
multi-stopSouthwest
8h 20mIAD-ONT
9/23Mon
multi-stopSouthwest
7h 20mONT-IAD
$894
9/21Sat
multi-stopSouthwest
8h 20mIAD-ONT
9/23Mon
multi-stopSouthwest
9h 05mONT-IAD
$1,059
9/21Sat
multi-stopUnited Airlines
9h 21mIAD-ONT
11/1Fri
multi-stopUnited Airlines
6h 36mONT-IAD
$1,354
9/22Sun
multi-stopAmerican Airlines
9h 36mIAD-ONT
10/3Thu
multi-stopAmerican Airlines
9h 19mONT-IAD
$1,521

Search by stops

Search by airline

Search by price

Everything you need to know for your flight from Dulles Intl to Ontario

Information on your arrival and departure airports