ONT - IAD

$92 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 4/20. 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
1 adult, Economy, 0 bags

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
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

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

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

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

Everything you should know

Cheapest round-trip
$260
Overall average: $578
Frontier
Tue 3/24Tue 4/7
ONT - IAD • 2 stops
Cheapest one-way
$92
Typical prices: $224-$408
Frontier
Mon 4/20
ONT - IAD • 2 stops
Top airlines
Frontier
Cheapest • from $260 (round-trip)
Southwest
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
4 weeks
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 51% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
July
Cheapest • 38% price drop
July
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Dulles Intl!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights 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.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ontario to Dulles Intl

Tue, Mar 24 - Tue, Apr 7
Frontier Logo
6:15 am - 11:56 pm
ONT
-
IAD
14h 41m
2 stops
Frontier Logo
8:30 pm - 4:23 pm
IAD
-
ONT
22h 53m
1 stop
$260Frontier
Thu, Apr 16 - Sat, Apr 18
Frontier Logo
6:15 am - 6:19 pm
ONT
-
IAD
9h 04m
1 stop
Frontier Logo
10:51 am - 7:31 am
IAD
-
ONT
23h 40m
2 stops
$277Frontier
Wed, Mar 11 - Tue, Mar 17
Delta Logo
10:25 pm - 9:10 am
ONT
-
IAD
7h 45m
1 stop
Delta Logo
7:20 am - 12:23 pm
IAD
-
ONT
8h 03m
1 stop
$297Delta
Tue, Mar 3 - Tue, Mar 10
Delta Logo
10:20 pm - 11:53 am
ONT
-
IAD
10h 33m
2 stops
Delta Logo
6:01 am - 11:47 am
IAD
-
ONT
8h 46m
1 stop
$302Delta
Tue, Mar 3 - Tue, Mar 10
Delta Logo
10:20 pm - 1:34 pm
ONT
-
IAD
12h 14m
2 stops
Delta Logo
6:00 am - 5:12 pm
IAD
-
ONT
14h 12m
2 stops
$307Delta
Thu, Mar 12 - Wed, Mar 18
United Airlines Logo
11:59 pm - 11:49 am
ONT
-
IAD
8h 50m
1 stop
United Airlines Logo
4:10 pm - 10:57 pm
IAD
-
ONT
9h 47m
1 stop
$308United Airlines
Mon, Apr 20 - Thu, Apr 23
Frontier Logo
6:15 am - 6:19 pm
ONT
-
IAD
9h 04m
1 stop
Frontier Logo
9:51 am - 11:24 pm
IAD
-
ONT
16h 33m
2 stops
$309Frontier
Tue, Mar 3 - Tue, Mar 10
Delta Logo
5:00 pm - 9:13 am
ONT
-
IAD
13h 13m
2 stops
Delta Logo
6:01 am - 11:47 am
IAD
-
ONT
8h 46m
1 stop
$312Delta
Thu, Mar 12 - Tue, Mar 17
Delta Logo
12:57 pm - 12:27 am
ONT
-
IAD
8h 30m
1 stop
Delta Logo
2:15 pm - 11:51 pm
IAD
-
ONT
12h 36m
2 stops
$313Delta
Fri, Apr 17 - Mon, Apr 20
Frontier Logo
6:15 am - 6:19 pm
ONT
-
IAD
9h 04m
1 stop
Frontier Logo
6:20 am - 11:55 pm
IAD
-
ONT
20h 35m
2 stops
$316Frontier
Booking Insights

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 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 July, where tickets cost $307 (return) on average. On the other hand, the most expensive months are January and November, where the average cost of round-trip tickets is $807 and $686 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, which saves you about 51% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 23 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$92
Best time to beat the crowds but there is an average 14% increase in price.
Most popular time to fly and prices are also 38% 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 $92 for a one-way ticket and $260 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?

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

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

    The two airlines most popular with KAYAK users for flights from Ontario to Washington, D.C. are Southwest and Delta. With an average price for the route of $457 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $426 and an overall rating of 7.9.

  • 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.

Reviews of the 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 4280 reviews
8.0Comfort
8.1Boarding
8.6Crew
7.5Entertainment
7.0Food
Airline reviews

The seats are now more narrow. I paid for front row the seats in the front are even more narrow than before.

2.0 MediocreDavid, Feb 2026
SAN - LAS
Read more Southwest reviews

The seats are now more narrow. I paid for front row the seats in the front are even more narrow than before.

The wifi on the plane is great. The only issue that I have is that I prefer an aisle seat and on my trips this week, I was either in the middle or window. If we can work to secure aisle seating, I will be thrilled. Nice trip.

Great flight but super high price. Glad it was a business trip and not personal

3 hour delay. Had to change plans and was still delayed.

We got exit row seats both flights. Everything was running on time

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

Delta One is extraordinary. I fly business when somebody hires me. I just wonder why there is such a chasm between business class and the insanely inhumane and nonsensical coach. The seats are not large enough to fit even my tiny wife. We fly 10% of what we did because we don’t want to pay 5-10 k but for $400 it’s unbearable. It seems like the accountants took over and made stupid decisions. Screw in 20 extra seats and make it so unbearable that people fly 90% less. Just put the damn price up and put some proper chairs in. But business, yay.

Delta’s staff is unmatched. From the gate agents, to the pilots, to the flight attendants… all top of the industry.

Flight was delayed several times. At one point, they "pulled back" 15 minutes from the delayed boarding and sent a text saying we would board sooner than previously advised. The flight then was delayed again. And when we boarded, there was an unspecified technical issue which had us waiting in the plane for about an hour.

The flight was delayed for about 2 hrs. Other than it, it was good.

I am extremely disappointed that delta internal pilot manuals now refer to the Gulf of Mexico as the “gulf of America”. You can bow down to the Orange turd on your own. I will never fly delta again

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

The flight used a B767 with a very old interior from before 2014. The entertainment system did not work at all during the flight despite attempts to reset the system. It was like they flew this route just to be competitive.

Delayed flight (1hour) plus a long layover after an overnight flight with no backup plane available.

Crew was great. 2 1/2 hour delay was due to staff needing "rest" was avoidable and self inflicted as United not willing to hire enough crew to keep flight on time.. Ridiculous. The crew and the passengers both suffered due to this.

Fine not above and beyond as I had a connection that was delayed due to maintenance

Bad food, bad service, cold cabin with no additional blankets when asked for (they told me they don’t provide additional blankets). I’m a frequent traveler and this is one of the worst companies I traveled with (by the way I thought that I booked my ticket with Lufthansa but I didn’t see that the flights were handled by United).

Great other than a couple very drunk guys that for a while kept bumping my seat from behind. The staff did their best to control them. Even refused serving them alcohol and allowed the gal sitting next to them to move.

Good crew. Boarding delays. Almost two hours wait for the bags in DC.

Unfortunately weather delayed our flight waiting for our plane to arrive and due to a little snow time was needed to deice the plane so departure was very delayed and I missed the connecting flight

It was great. There were some issues prior to takeoff. The weather was poor so we had to go through deicing, and we were delayed a bit by the pilots' concern about one of the engines, but that's aviation. The pilots handled everything with aplomb, and kept us apprised

The seats were comfortable and we had leg room. Great entertainment.

The flight crew where really good. Better then the crew from BNE to SFO

Safe made to destination. Late to start at GVA for icy reasons but we fought our next fly.

The flight was on time/early, attentive crew, and everything overall went smoothly. Disappointed that WIFI was not working for the flight.

Concern Regarding Significant Gate Delay and Jet Bridge Issue Dear Customer Relations Team, I am writing to express my disappointment with the experience I had on my recent flight AA 2414 on Sunday January 18, 2026. What should have been a routine departure turned into a frustrating and avoidable delay due to an issue with the jet bridge at the gate. As a result, the flight was delayed by approximately 90 minutes while multiple gate changes were attempted. The lack of clear communication during this period made the situation even more challenging. Passengers were left uncertain about the cause of the delay, the expected timeline, and the next steps. This not only disrupted travel plans but also created unnecessary stress for everyone on board. I understand that operational issues can arise, but a malfunctioning jet bridge and the resulting extended delay suggest an area where procedures or equipment maintenance may need attention. I hope you will review this incident to prevent similar disruptions in the future. I would appreciate acknowledgment of this concern and consideration of appropriate compensation for the inconvenience and lost time caused by this delay. Thank you for taking the time to review my experience. I look forward to hearing from you. Sincerely, Dion Dillard

The flight was on time and arrived early. The crew were friendly and helpful.

I got sick nothing contagious but distressing enough and the care I received on the flight was astounding.

Horrible. Both legs of my flight were delayed more than 6 hours. No compensation, no screens on the plane, and the plane was not clean.

After we'd boarded , they canceled the flight. The crew didn't even know , we just all received text messages. Then after they deplaned us , AA was just like "too bad, go F your self, we sure ain't gonna help you"

Initial flight was cancelled at the time of arrival to the airport, flight alternative requires switching from direct to flight with a layover, and the plane felt like it would split apart, it was so rattle-y.

The chair cushions may need an upgrade. I have been noticing they are so worn out, thin so you’d sit in a dip 😄. Other than that, all was an enjoyable trip. Thanks AA!

Weather delay for 2.5 hours followed by half hour crew delay, did not have ginger ale, uncomfortable seats

It was nobody’s fault - but the plane came 4-hrs late and we were updated randomly in 20-30 mins increments which left us hostage to sit and wait expectantly. It was very long and got very late. Our plane didn’t land until nearly 1 am! Also the toilet wasn’t working. The hosts were nice enough but were clearly “about to pass out” as one told me. Lastly, there was no snack or even time for it. Just a bad experience overall.

There was no food and no entertainment, so I'm not sure why these are even in the survey, as my understanding is frontier does not ever offer food without a few, not even a snack, and there are no screens so unless the flight safety talk is our entertainment why ask how we liked it?. One of the flight attendants say in the back of the plane as people filed in to their seats, yelling orders about where to put baggage and telling people to hurry up. It was the least professional experience I've ever had on a flight.

Very well recently! Frontier is improving and less harrassing customer on luggages! Positive!

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

I am writing to express my disappointment with my recent Frontier Airlines flight. I was charged $99 at the gate because my bag was said to be too large, yet once onboard there was no available overhead bin space, and I was required to place the bag under the seat in front of me anyway. This made the charge feel unnecessary and unfair. Additionally, before the flight even took off, I was asked to move from the seat I paid for into a middle seat so another passenger and her cat could have my seat to themselves. I was not offered compensation or an explanation for being moved from a paid seat. Between the unexpected bag fee and being forced to give up my seat, this experience fell well below acceptable customer service standards. I would appreciate a review of this situation and appropriate compensation.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

This airline sucks. They offer low rates then charge you for everything, the app does not work well, the seats are the most uncomfortable. Maintenance issues on the flight, and you still have to sit through their credit card commercials. People are nice enough but does not make up for overall poor experience.

The worst. We never made our connection and they did absolutely nothing to help us at the airport.

Cancelled flight after I arrived at airport after 75 min drive and parking. Next flight was 4 days in the future. Had to scramble and buy a much more expensive flight on another carrier.

I liked the turn-style feature at gate 209B at LAX. Very efficient process. The gate staff also made several, clearly directed announcements so I felt very informed.

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

Information on your arrival and departure airports