ONT - IAD

$95 Find Cheap Flights from Ontario to Washington Dulles Airport

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to Dulles Intl departing on 5/30. 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.
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KAYAK searches hundreds of travel sites at once for deals on flights to Washington, D.C. Dulles Intl Airport

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to Washington, D.C., 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 Ontario to Washington, D.C., as well as popular online travel agencies
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Cheap Flight Deals from Ontario to Dulles Intl (ONT-IAD)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to Dulles Intl 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.

Recent round-trip flight deals from Ontario to Dulles Intl

KAYAK's recommended round-trip deals from the most popular airlines that fly from Ontario to Dulles Intl.
Discover the best prices for you by selecting your travel dates on KAYAK.
Frontier Logo
5:15 pm - 5:55 amONT-IAD
9h 40m1 stop
Frontier Logo
7:25 am - 11:43 amIAD-ONT
7h 18m1 stop
$198Frontier
Find Deal
Sat, May 24 - Wed, May 28
Frontier Logo
7:37 pm - 5:55 amONT-IAD
7h 18m1 stop
Frontier Logo
10:52 am - 7:43 pmIAD-ONT
11h 51m1 stop
$208Frontier
Find Deal
Wed, May 28 - Thu, May 29
Delta Logo
2:55 pm - 5:52 amONT-IAD
11h 57m1 stop
Delta Logo
6:00 am - 11:08 amIAD-ONT
8h 08m1 stop
$327Delta
Find Deal
Tue, May 27 - Fri, May 30
Delta Logo
1:00 pm - 11:53 pmONT-IAD
7h 53m1 stop
Delta Logo
12:30 pm - 10:41 pmIAD-ONT
13h 11m2 stops
$332Delta
Find Deal
Fri, Sep 5 - Tue, Sep 9
American Airlines Logo
7:05 pm - 8:38 amONT-IAD
10h 33m2 stops
American Airlines Logo
11:50 am - 9:38 pmIAD-ONT
12h 48m2 stops
$337American Airlines
Find Deal
Thu, Jun 5 - Sat, Jun 14
United Airlines Logo
1:36 pm - 12:45 amONT-IAD
8h 09m1 stop
United Airlines Logo
5:18 pm - 10:11 pmIAD-ONT
7h 53m1 stop
$354United Airlines
Find Deal
Wed, Jun 18 - Sat, Jun 28
Southwest Logo
5:30 am - 4:50 pmONT-IAD
8h 20m1 stop
Southwest Logo
5:50 pm - 11:30 pmIAD-ONT
8h 40m1 stop
$359Southwest
Find Deal
Wed, Jul 16 - Mon, Jul 21
American Airlines Logo
12:41 pm - 10:57 pmONT-IAD
7h 16m1 stop
American Airlines Logo
11:50 am - 7:01 pmIAD-ONT
10h 11m1 stop
$364American Airlines
Find Deal
Sat, May 10 - Sat, Jun 14
Southwest Logo
5:30 am - 5:55 pmONT-IAD
9h 25m2 stops
Southwest Logo
7:50 am - 7:30 pmIAD-ONT
14h 40m2 stops
$407Southwest
Find Deal
Wed, May 28 - Wed, Jun 4
United Airlines Logo
6:41 pm - 7:19 amONT-IAD
9h 38m1 stop
United Airlines Logo
6:32 am - 12:14 pmIAD-ONT
8h 42m1 stop
$427United Airlines
Find Deal
Sun, Jun 22 - Thu, Jun 26
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KAYAK's insights & trends for Ontario to Dulles Intl flights

Get data-powered insights and trends into flights from Ontario to Dulles Intl 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 Ontario to Washington Dulles Airport?

The average price of all round-trip flights from Ontario to Washington, D.C. Dulles Intl Airport clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from Ontario to Washington Dulles Airport, look for departures on Thursdays and avoid leaving on a Monday, as it's usually the priciest day. When flying back from Washington Dulles Airport, Thursday is the cheapest day to fly and Saturday is the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to Washington, D.C. Dulles Intl Airport, 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 Ontario to Washington, D.C. Dulles Intl Airport is August, where tickets cost $336 (return) on average. On the other hand, the most expensive months are December and March, where the average cost of round-trip tickets is $587 and $552 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to Washington, D.C. Dulles Intl Airport, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ontario to Washington, D.C. Dulles Intl Airport, you should book around 4 weeks before departure. For the absolute cheapest price, our data suggests you should book 22 weeks before departure.

Good to know

Low seasonJanuary
High seasonMay
Cheapest flight$95
Best time to beat the crowds but there is an average 6% increase in price.
Most popular time to fly and prices are also 3% lower on average.
Flight from Ontario to Washington Dulles Airport

When to book flights from Ontario to Dulles Intl

Are your dates flexible? Find out the best times to travel from Ontario to Dulles Intl 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 Ontario to Washington Dulles Airport flights

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

    In the last 3 days, the lowest price for a flight from Ontario to Washington, D.C. Dulles Intl Airport was $95 for a one-way ticket and $198 for a round-trip.

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

    No

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

    Ontario airport is called Ontario and the only airport in Washington Dulles Airport is Washington, D.C. Dulles Intl.

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

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

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

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

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

    The two airlines most popular with KAYAK users for flights from Ontario to Washington, D.C. are Delta and Southwest. With an average price for the route of $387 and an overall rating of 8.0, Delta is the most popular choice. Southwest is also a great choice for the route, with an average price of $510 and an overall rating of 8.0.

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

    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 Ontario to Washington Dulles Airport.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Washington Dulles Airport from Ontario 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 Ontario to Washington Dulles Airport?

    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 Washington Dulles Airport with an airline and back to Ontario with another airline. Booking your flights between Ontario and IAD 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 Ontario to Washington Dulles Airport?

    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 Washington Dulles Airport from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Top 5 airlines serving from Ontario to Dulles Intl

 
See real verified KAYAK customer reviews for airlines flying from Ontario to Washington, D.C.. 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 Ontario to Dulles Intl? 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
SouthwestOverall score based on 4294 reviews
8.2Boarding
7.6Entertainment
8.0Comfort
7.1Food
8.6Crew
Airline reviews

It was a perfect flight in all aspects! Both legs!

10.0 ExcellentAnonymous, Apr 2025LGB - SMF
Read more Southwest reviews

It was a perfect flight in all aspects! Both legs!

Great flight, 47 passengers on a 180 seat plane. Stewardess was pleasant and cheerful.

I liked the crew member who gave flight instructions on "in case of a problem:. The seats are so small that only a young teenager could sit in middle seat.

Great flight staff. Ease of boarding. Overall, very uneventful and easy trip.

Employees were kind and funny, as always! Flight was late but no announcements were made for people with tight connections to help them transition quickly. No service due to turbulence.

I recently flew Southwest from San Jose to Honolulu. I was very impressed with the flight crew, especially the flight attendant in charge of the front of the plane. She came through the aisle at least five times for drinks and water, and two times for snacks. I have not seen such service since I flew first class. Also, for the first time, they gave us the correct baggage claim number, and the luggage came out quickly. I can't wait for Southwest to have assigned seating! I absolutely hate the Cattle Call boarding procedure and the mad dash to get seats and overhead bins. However, the boarding was efficient.

We had a nice flight. Boarding was easy, our seats were comfortable and the on board service was pleasant.

Service was great, boarding and exiting went smoothly, and the flight was very pleasant.

Was as expected. Crowed planes. Too many carryons delaying takeoff. But the ride only took an hour and saved me a lot of time SFO is a not a great airport.

Was as expected. Crowed planes. Too many carryons delaying takeoff. But the ride only took an hour and saved me a lot of time SFO is a hell hole of an airport. It is the new LaGuardia. Everything Cobbled together. Security gates closed. Terri directional signage

Delta flight was on time, seats were comfortable, and crew was nice.

The Dekta Rep that checked us in was great. She's very personable, pleasant, and can tell she enjoys her job.

Thank you for not flipping the plane on the run way. You guys get a 5 star rating for the flight!!!

Boarding is, as it always is… horrible. Gate lice. Slow moving zones. Too many people with carry ons

It was terrible, if they ran flights on time it would make a big difference.

Delta seems to be improving in many areas, except they are super bad with the food available. Bring back normal food service on long flights.

I actually received a notification from kayak on email but not one by text from Delta when my departure gait changed and I almost missed my flight

New boarding doesn't make sense. Filling front first is slow.

Delta flight was great from the check in all the way to arrival. However, I had a very bad experience. I requested a wheelchair and the wheelchair employee that went to pick me up from the plane in Boston to bring me to the baggage claims told me I have to pay him. I was under the impression that it was a free service and I usually give tips but the person forced me to pay and since I said no because I was upset with his demand when my daughter walked in to pick me up he demanded payment from my daughter who paid him thinking maybe now it is a charged service.

Horrible. Grateful to be alive but spent 13 hours at airport only to return back to my familys house and flight changed to next day. They tried to fix a part on plane, had no back up plane and after 10 hours , reattempted the flight and it STILL wasn't fixed. We got a meal voucher and rescheduled flight but there should be some other compensation for the 15 hours spent in airport

Mostly the experience was good except for the flight changes made by UA which meant longer layover in DC

Terrible. First of all we were delayed 4 3/4 hours departing Honolulu. As we had to leave our condo and the rental car had to be returned we had to go to the airport. Even though we had a business class boarding pass to Washington, since we did not have business class to Montreal we could not access the lounge without paying a $59 fee each. This does not make sense to us. Since we could not meet our original connection United booked us to Montreal via New York LaGuardia on Air Canada. In Washington a further delay got us into LaGuardia too late to make our connection to Montreal so we were booked on another Air Canada flight 3 hours later. We were originally scheduled to arrive in Montreal at 10:40 and arrived at 19:55. A totally exhausting day, United did not offer a meal voucher or any type of compensation. Air Canada did give us a digital meal voucher. The food in United business class is poor among all meals offered. The pods look nice but are not that confortable. Overall would not fly on United again.

Change cabin crew assisting business class. Not taking care, ignoring requests and calls. Never had such an experience in business class.

United left one of our bags back in SFO but that’s not my real complaint. The complaint is how it all went down. So we checked in the day before online and were told we could use the quick drop for luggage. So the next day I used baggage quick drop curbside at SFO. The agent mistakenly didn't tag my bag as he put my bag on the conveyor belt untagged. We immediately alerted him he had not tagged the bag. I walked with him to the baggage service office to find my bag and tag it. We waited outside the office for 10 mins. He came out and said everything was ok and the bag was going to be tagged and on my flight. We received a text that one of our bags was on the flight but the other was not. I alerted my first class flight attendant immediately upon boarding the flight. She was helpful and said she’d get it sorted out right away. She called over the gate agent. The gate agent used my bag number and looked over information on her device. She said my bag was on the flight. The flight attendant was standing with her, looking at the device, and also said “yep it’s on the flight”. During the flight the flight attendant made reference to how reassuring it must feel knowing the bag was on the flight. Upon arriving to IAD we received a text that my bag was not on my flight. The text said my bag would arrive to my final destination LIS 24 hrs late. I understand that mistakes happen. I was totally ok with my bag mistakenly not getting tagged at the quick drop. I was fine with walking down to baggage services to tag my bag. But, what I am not ok with is that the United staff said they fixed the mistake two different times, assuring me twice that my bag would be/was on the plane…and it wasn’t. I expected better attention by the employees, for them to do what they said they were going to do. We also spent extra money to upgrade our seats to first class, including the entire return leg from Lisbon to San Francisco because we wanted a smoother and more relaxing travel experience. Our money was not well spent. We will not be using United for travel going forward.

The flight was delayed, it took longer than anticipated because of weather, and they broke my luggage.

Horrifying! And I am almost 2 million miles with United. Late by 3 1/2 hours. Worst: after two hours on the plane waiting, they decided that one of the tires had been damaged and then decided to change it. Another hour and a half to change the tire!!!!! NO EXCUSE FOR THIS. The crew didn't even offer a glass of water until we had been on the plane for FIVE hours. This is the worst airline in the world. I'm simply stuck because they fly on the only routes I need.

Gate got changed about 4 times. Very confusing and very crowded. If you don’t have wifi to help get updates, you can be in deep trouble.

Attendants zipped through cabin so fast hardly anyone got the water they told us we could have in the short flight. Nothing else was offered.

Sucks ! All three flights I was on this trip were delayed.

The flight attendants were unhelpful. It was a packed flight, and usually a flight attendant would help find a spot in the bin for your carry on or shift things around. Neither made any effort to do so. Also, I had to then check my bag. I was told it would be on the carousel in YYZ, but it came up on the jetway. So lucky I saw others standing around for their bags. I would have walked straight past this and on to the carousel. They could have at least told me that they had given me wrong information. Very unsatisfactory.

Very helpful ground crew after an earlier flight delay and being rebooked on a different flight.

The plane was late and then sat on the runway for almost 45 minutes before taking off.

We kept being told that the flight was full and that all overhead compartments were full and therefore had to check in our hand luggage. We were some of the last people to board and noticed that there was still sufficient space in the overhead compartments. We were obliged to check in hand luggage when there was space and so had to wait at luggage retrieval which took a while to then noticed damage to our luggage - not a great experience!

This was an overnight flight. There was no meal service in first class, just a simple snack basket was offered along with beverages. There should have been some type of continental breakfast prior to arrival in PHL. As an Executive Platinum American Airlines Advantage member, I received no name recognition from the first class flight attendant. When disembarking at PHL, the flight attendants were more interested in their cell phones than saying "thank you" to the passengers as they disembarked.

The flight was quick and to the point. The crew just did their job w/o excessive talking and everything was just perfect.

The boarding crew was incredibly helpful getting me on an earlier flight

Great experience. Flight boarded easily. Departed early. Smooth flight. Great arrival in DC--almost no taxing! Almost direct to gate from runway. Crew was terrific. Same cookies and beverages in main cabin. I did not use the entertainment system on this flight.

Flight delayed on both ends - have a gate ready at DCA, don't make us sit for 30min after being late to take off as well.

AA can't control the weather. But the airplane was hot and stuffy while stuck on the runway with a broken entertainment system.

very bare bones flight no entertainment screen, download shows prior to boarding to watch on phone or tablet.

The seats were awful, hard plastic covered in sheet vinyl. The airline tries to scam you into paying extra to get seat together when the flight wasn’t full. They were going to separate a family with young children but my wife who had a row to herself gave up her seat so the young mom could be with her young boys. I’m never giving this airline my money again.

It was a short flight so no food or entertainment….

Frontier had yet another flight cancellation. Have never made a complete round trip with this airline without at least one leg getting cancelled. Miserable flights - dirty, uncomfortable planes that apparently always have issues since I've had multiple delays and cancellations with them.

Flight was delayed 3 times, would have been nice to have received text message instead of email notifications. Frontier app wasn’t even updated accordingly, no gate number disclosed. No agent at front desk of gate to inform of delay. Very confused and left if the dark

They changed the timing , first delayed by 4 hours then went back to 40 mins late, we had to run back to airport to not miss our flight. This is ridiculous

No frills for sure. No gate announcements about flight delay, not even water to drink on the flight.

I loked walking out on the tarmac to board and no first class. I didn't like that they have no snacks or onboard wifi to bide your time.

It was a redeye flight, so every passenger just wanted to sleep, but through the entire flight, the flight crew made announcements over the loudspeaker at maximum volume every few minutes making sleep impossible. For example: it’s 2am, and the crew decides to give an extremely detailed announcement about snacks and beverages for sale. And 3am is the perfect time to wake up everyone with a lengthy announcement about how to get a coffee refill and how to take advantage of new offer from frontier for a credit card.

The takeoff was the smoothest I've ever experienced on any airline and this is the first time I've flown on frontier so this was an extremely pleasant surprise!

A lady asked to stop the flight after the tunnel pulled away and we began to depart a flight that was already hours late. The attendance respectfully stopped the the plane and had the tunnel return. After the tunnel returned the passenger claimed to have changed her mind . The tunnel was then put in reverse and the passenger remained on the plane .. They should have sent the sick passenger off the plane like initially replaced. They existed a couple off the plane prior to that situation.. So.. all and all.. it was a long and flight.. .

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