IAD - ONT

$110 Find Cheap Flights from Washington Dulles Airport to Ontario - Compare and Save

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 8/29. 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 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
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Everything you should know

Cheapest round-trip
$322
Typical prices: $254-$409
Frontier
Fri 7/24Tue 8/11
IAD - ONT • 1 stop
Cheapest one-way
$110
Typical prices: $150-$427
Frontier
Sat 8/29
IAD - ONT • 1 stop
Top airlines
Cheapest • from $322 (round-trip)
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Dulles Intl and Ontario. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $360 (round-trip)
Shortest trip • 7h 09m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 43% price drop
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 Ontario!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Dulles Intl 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 Dulles Intl 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 for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Dulles Intl to Ontario

Fri, Jul 24 - Tue, Aug 11
Frontier Logo
9:50 am - 8:03 am
IAD
-
ONT
25h 13m
1 stop
Frontier Logo
4:09 pm - 8:20 am
ONT
-
IAD
13h 11m
1 stop
$322Frontier
Tue, Aug 11 - Tue, Aug 18
Frontier Logo
9:50 am - 3:14 pm
IAD
-
ONT
8h 24m
1 stop
Frontier Logo
3:40 pm - 8:04 am
ONT
-
IAD
13h 24m
1 stop
$323Frontier
Fri, Jul 24 - Tue, Aug 11
Frontier Logo
8:33 pm - 3:14 pm
IAD
-
ONT
21h 41m
2 stops
Frontier Logo
4:09 pm - 8:20 am
ONT
-
IAD
13h 11m
1 stop
$324Frontier
Tue, Aug 18 - Sun, Aug 23
Frontier Logo
9:13 am - 3:54 pm
IAD
-
ONT
9h 41m
1 stop
Frontier Logo
8:17 am - 6:29 pm
ONT
-
IAD
7h 12m
1 stop
$325Frontier
Fri, Jul 24 - Tue, Aug 11
Frontier Logo
8:33 pm - 3:14 pm
IAD
-
ONT
21h 41m
2 stops
Frontier Logo
4:09 pm - 8:20 am
ONT
-
IAD
13h 11m
1 stop
$326Frontier
Wed, Aug 12 - Sun, Aug 16
Frontier Logo
9:50 am - 3:14 pm
IAD
-
ONT
8h 24m
1 stop
Frontier Logo
4:09 pm - 10:25 am
ONT
-
IAD
15h 16m
2 stops
$327Frontier
Tue, Aug 11 - Mon, Aug 17
Frontier Logo
9:50 am - 3:14 pm
IAD
-
ONT
8h 24m
1 stop
Frontier Logo
4:09 pm - 8:04 am
ONT
-
IAD
12h 55m
1 stop
$328Frontier
Fri, Aug 7 - Sat, Aug 8
Frontier Logo
9:50 am - 3:54 pm
IAD
-
ONT
9h 04m
1 stop
Frontier Logo
8:17 am - 10:52 pm
ONT
-
IAD
11h 35m
2 stops
$331Frontier
Tue, Jul 28 - Sun, Aug 2
Frontier Logo
9:50 am - 3:14 pm
IAD
-
ONT
8h 24m
1 stop
Frontier Logo
3:40 pm - 10:25 am
ONT
-
IAD
15h 45m
2 stops
$332Frontier
Tue, Jul 28 - Mon, Aug 17
Frontier Logo
9:50 am - 3:14 pm
IAD
-
ONT
8h 24m
1 stop
Frontier Logo
4:09 pm - 8:04 am
ONT
-
IAD
12h 55m
1 stop
$333Frontier
Booking Insights

KAYAK's insights & trends for Dulles Intl to Ontario flights

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.

How much is a round-trip flight from Washington, D.C. Dulles Intl Airport to Ontario?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Washington, D.C. Dulles Intl Airport to Ontario departing in July.

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 round-trip 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 September, where tickets cost $273 (return) on average. On the other hand, the most expensive months are April and March, where the average cost of round-trip tickets is $917 and $637 respectively.

Good to know

Low seasonJanuary
Cheapest flight$110
Best time to beat the crowds with an average 10% drop in price.
Most popular time to fly with an average 2% 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 5 days, the lowest price for a flight from Washington, D.C. Dulles Intl Airport to Ontario was $110 for a one-way ticket and $322 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?

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

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

    The two airlines most popular with KAYAK users for flights from Washington, D.C. to Ontario are Southwest and Delta. With an average price for the route of $417 and an overall rating of 7.9, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $397 and an overall rating of 7.8.

  • 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.

Reviews of the top 5 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.
7.9
SouthwestOverall score based on 4246 reviews
8.6Crew
8.0Comfort
7.5Entertainment
7.0Food
8.1Boarding
Airline reviews

The flight was late. The crew was rude. There was no food. Cramped and uncomfortable. Nothing about this flight was good.

2.0 MediocreIrene, Jun 2026
DEN - SFO
Read more Southwest reviews

The flight was late. The crew was rude. There was no food. Cramped and uncomfortable. Nothing about this flight was good.

It was just okay, no frills, basic transportation with no luxury. No screens on the seats, no water or drinks on a short flight. Full flight but at least it was on time.

The first time I flew in the extra legroom section. It was difficult to notice a difference. I had bad luck with my neighbors. The crew was okay. Southwest has reduced the live TV options.

Haven’t flown on SW in years. Flight was on time departing and arriving. Served vegan butter onion flavored pretzels which were bad. Coke served was in a tiny paper cup. Crew was not engaging. Felt like they were going through the motions. Old plane, tight seats and no leg room.

No delays and arrived to destination 30 min early. Staff was super friendly.

Pretty standard flight. We left late, but arrived early. The wifi entertainment is always nice. The free snacks and beverages are simple, but appreciated. I'm tall and the seats are an issue. I can deal with a short flight, but any longer, I have to find another airline where I know beforehand I have extra legroom.

Our flight to Oakland was great bc the plane was new but it was delayed by 15min not bad at all. Over all it was an 8/10

The flight in it self was good. The delays looking for pilots was unexpected.

Awesome experience. No in-flight video or meal. Still do not like the boarding process.

On time, good crew, easy flight. Just like the old days!

Crew was real good, flight was smooth and came in early.

Love me some Delta. One of the few airlines to recognize and support veterans. Easy boarding, flight was on time and arrived early and the flight attendants were excellent on this flight.

The gentleman at the gate I think his name is RIE was exceptional

This flight was no comparison to our prior flight. I'm thinking it all has to do with the age of the aircraft.

2 of the seats in row 31 the entertainment system was not working, and one seat the tray table did not go all the way down. Flight arrived early and departed on time which was great.

Waited at the usual crowded gate at DCA where one ends up standing up because there aren't enough seats.

Delayed take-off. Very small plane so very scary with lots of bumps during the flight. Would never fly Delta on short flights in small 80 seaters plane again! Felt relieved when landed.

Inexpensive, got an exit row aisle aeat with no middle passenger, bought a great breakfast sandwich, flight comfortable & arrived ahead of schedule.

I wouldn't say I liked being forced to check my small roller bag at the gate; too many people had bags and were in a higher boarding group.

715PM departure was 2.5 hours late. Received hotel & food voucher but after we already booked a room. Entire team just seemed like they were 2-3 steps behind in execution, and notifcations.

Like: departed and arrived on time. Unlike: Food options for purchase allways bad, 1 of 2 of the crew members not very friendly at all. Seats and leg room aweful. At this point I am thinking on switching to AA.

United didn’t even try to hold the flight for me. They knew I had a tight connection and when I arrived at the gate less than 10 mins after final boarding the flight had already gone. The gate agent wasn’t even notified that I was on my way. She was told I wasn’t at the airport

7 hours delayed due to operational issues on United’s end. Basically laziness.

We were given vouchers we couldn’t use with a 5.5 hour delay

This was a 5 hour flight with no entertainment and with a snack being provided (pretzels and fruit bar), which are both high in carbs and sugar. Nuts would have been a better choice.

Good plane, crew, and flight. Boarding was a bit chaotic. Bathrooms were unacceptable. United DESPERATELY needs a new terminal at IAD.

Should have video screens Plane audio was poor and without wired connection hard to understand crew. Should serve more than just cups of water and pretzels on six hour flight. Did not see crew rest of flight. Fix charging sockets to retain charging blocks.

Airline did not explain reasons why flight was delayed two hours. Explanations were badly needed and rarely provided. Problem seemed to clearly be the airline’s fault and not the fault of the weather or airport.

787-9 Transcon from IAD-LAX FYI no meals in premium plus, not considered Premium - seats are wonderful https://www.united.com/ual/en/us/fly/travel/inflight/premium-services.html Horrible handling of delayed flight

I was crammed against a person too large for one seat. This traveler (who I’m sure you have a record of, 21E) should be required to purchase two tickets in the future. Also, your streaming service kept kicking me out of my movie.

The seats were extremely cramped, with very little legroom or personal space. There was no room left in the overhead bins for a backpack, and the space under the seat in front was so limited that I could barely fit my bag underneath. Overall, the seating arrangement felt very uncomfortable and overcrowded.

As always, most AA flights that we fly are almost ALWAYS delayed and that too multiple times. Very frustrating

The small flights with Valet Luggage has a poor service

Going non stop to lax like I paid for. Not stopping in MCI for gas. Too long of delays

Human interaction. Thought there would be more service-even a smile would have been nice.

Smooth flight. From the early boarding and all were on board before departure time and arrived early in ONT. Great crew. Thank you!!!!

Amazing I love American. I’ll never fly anyone else if I can help it.

We were told the flight was delayed 5 times, then it was moved to the next day.

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

It was fine. I didn't love the food but it was at least a real attempt at serving a meal, unlike my earlier flight from Nashville to Dallas.

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

Frontier Airlines was AWFUL. I was an hour early for my flight and the lady refused to check me in. I had to purchase a whole new ticket with a different airline.

I missed a flight because of a delay. I had to buy a new ticket through Southwest.

The crew was mostly okay. The flight attendant who answered our questions was curt and unhelpful unfortunately. He seemed upset and I understand having off days.

Bag should not be so much money. This is how Frontier takes advantage of customers

Frontier is definitely a good option for people traveling light or on a budget - just remember to bring your own entertainment and your own headphones if you need them.

Flight was cancelled and was not able to get another flight thru Frontier. Per frontier a refund was issued but I do not see a refund on my Afirm account.

The agent at check-in was strident, unwelcoming, and condescending to customers ahead of me.

Was charged 99 dollars for a bag despite agents previously telling me it would be ok. Customer service was unhelpful

I will like you ( Frontier Airlines) to fly into LAX instead of ONT because I live in LA and the subway takes me to my house in just 15 minutes

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

Information on your arrival and departure airports