WAS - ONT

$87 Find Cheap Flights from Washington, D.C. 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 Washington, D.C. to Ontario departing on 4/28. 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
$191
Overall average: $298
Frontier
Sat 4/18Mon 4/20
DCA - ONT • 1 stop
Cheapest non-stop
$355
Southwest
Tue 5/12Tue 5/19
BWI - ONT • Non-stop
Top airlines
Cheapest • from $191 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Top layover airports
Cheapest • Avg $282 (round-trip)
Shortest trip • 7h 05m (one-way)
Insights
Insights
Insights
Insights
Top routes
Cheapest
Most popular
Insights
Insights
Insights
Insights
When to travel
Cheapest • 44% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Washington, D.C. to Ontario (WAS-ONT)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Washington, D.C. 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 Washington, D.C. to Ontario

Sat, Apr 18 - Mon, Apr 20
Frontier Logo
6:00 pm - 11:55 pm
DCA
-
ONT
8h 55m
1 stop
Frontier Logo
12:59 am - 1:00 pm
ONT
-
DCA
9h 01m
1 stop
$191Frontier
Sat, Apr 18 - Mon, Apr 20
Frontier Logo
6:00 pm - 11:55 pm
DCA
-
ONT
8h 55m
1 stop
Frontier Logo
12:59 am - 1:00 pm
ONT
-
DCA
9h 01m
1 stop
$194Frontier
Sat, Apr 18 - Tue, Apr 21
Frontier Logo
6:00 pm - 11:55 pm
DCA
-
ONT
8h 55m
1 stop
Frontier Logo
12:59 am - 9:59 pm
ONT
-
DCA
18h 00m
1 stop
$200Frontier
Tue, Apr 28 - Fri, May 1
Frontier Logo
8:00 am - 11:55 pm
DCA
-
ONT
18h 55m
1 stop
Frontier Logo
5:33 pm - 1:00 pm
ONT
-
DCA
16h 27m
1 stop
$204Frontier
Wed, Apr 22 - Sun, Apr 26
Frontier Logo
8:00 am - 11:55 pm
DCA
-
ONT
18h 55m
1 stop
Frontier Logo
12:59 am - 1:00 pm
ONT
-
DCA
9h 01m
1 stop
$206Frontier
Wed, May 6 - Wed, May 13
Frontier Logo
5:17 pm - 7:35 am
BWI
-
ONT
17h 18m
1 stop
Frontier Logo
8:06 pm - 8:23 pm
ONT
-
BWI
21h 17m
1 stop
$210Frontier
Wed, Apr 8 - Tue, Apr 14
Frontier Logo
7:00 am - 11:56 pm
DCA
-
ONT
19h 56m
1 stop
Frontier Logo
12:59 am - 9:59 pm
ONT
-
DCA
18h 00m
1 stop
$210Frontier
Sat, May 2 - Tue, May 12
Frontier Logo
6:00 pm - 11:55 pm
DCA
-
ONT
8h 55m
1 stop
Frontier Logo
6:00 am - 9:58 pm
ONT
-
DCA
12h 58m
1 stop
$214Frontier
Tue, Apr 14 - Thu, Apr 23
Delta Logo
7:00 am - 10:37 pm
IAD
-
ONT
18h 37m
1 stop
Delta Logo
7:00 am - 11:55 pm
ONT
-
IAD
13h 55m
1 stop
$287Delta
Tue, Apr 14 - Tue, Apr 21
Delta Logo
7:00 am - 1:39 pm
IAD
-
ONT
9h 39m
1 stop
Delta Logo
7:00 am - 11:44 pm
ONT
-
IAD
13h 44m
2 stops
$292Delta
Booking Insights

KAYAK's insights & trends for Washington, D.C. to Ontario flights

Get data-powered insights and trends into flights from Washington, D.C. 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. 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. to Ontario departing in April.

What is the cheapest Washington, D.C. to Ontario flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest return flight from Washington, D.C. to Ontario costs $371 on the route between Baltimore (BWI) and Ontario (ONT). It is also the most popular route.

What is the cheapest month to fly from Washington, D.C. 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. 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. to Ontario is January, where tickets cost $206 (return) on average. On the other hand, the most expensive months are November and May, where the average cost of round-trip tickets is $468 and $416 respectively.

Can I save money by flying with a layover from Washington, D.C. to Ontario?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $379, prices are generally cheapest when you fly direct.

Good to know

Low seasonJanuary
Cheapest flight$87
Best time to beat the crowds with an average 45% drop in price.
Most popular time to fly with an average 4% increase in price.
Flight from Reagan Washington National Airport to Ontario

When to book flights from Washington, D.C. to Ontario

Are your dates flexible? Find out the best times to travel from Washington, D.C. 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 flights from Washington, D.C. to Ontario

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

    In the last 3 days, the lowest price for a flight from Washington, D.C. to Ontario was $87 for a one-way ticket and $191 for a round-trip.

  • Do I need a passport to fly between Washington, D.C. and Ontario?

    A passport is not required to fly from Washington, D.C. to Ontario.

  • Which airports will I be using when flying from Washington, D.C. to Ontario?

    Washington, D.C. is served by 2 major airports and there is only 1 main airport in Ontario. You will leave Washington, D.C. from one of these airports: Washington, D.C. Reagan-National or Washington, D.C. Dulles Intl. You will be arriving at Ontario.

  • Which airlines offer Wi-Fi service onboard planes from Washington, D.C. to Ontario?

    Alaska Airlines, and Hawaiian Airlines offer inflight Wi-Fi service on the Washington, D.C. to Ontario flight route.

  • Which aircraft models fly most regularly from Washington, D.C. to Ontario?

    The Boeing 737-800 Passenger/BBJ2 (winglets) is the aircraft model that flies most regularly on the Washington, D.C. to Ontario flight route.

  • Which airline alliances offer flights from Washington, D.C. to Ontario?

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

  • On which days can I fly direct from Washington, D.C. to Ontario?

    There are nonstop flights from Washington, D.C. to Ontario on a daily basis.

  • 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 $427 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 $376 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from Washington, D.C. 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, D.C. to Ontario.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from Washington, D.C. 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, D.C. 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, D.C. with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington, D.C. 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, D.C. up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Washington, D.C. to Ontario

  • Looking for a cheap flight? 25% of our users found flights on this route for $250 or less one-way and $398 or less round-trip.

Reviews of the top 5 airlines serving from Washington, D.C. 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 Washington, D.C. 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
SouthwestOverall score based on 4320 reviews
8.6Crew
7.5Entertainment
8.1Boarding
8.0Comfort
7.0Food
Airline reviews

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

8.0 ExcellentTobin, Mar 2026
SJC - BUR
Read more Southwest reviews

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

No food or entertainment, just a quick 40 minute flight. A little bumpy due to Santa Ana winds but pilot has no control over that. Good flight and landing!

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

Mediocre. Boarding is now unpleasant. The employees, once friendly and nice, are now regularly speaking sternly to passengers, badgering them to do things right so they can take off on time and gate check bags because they don't have enough overhead bin space. The pretzel snack was crushed flat and broken into even smaller pieces, which happens frequently lately. Drink service was suspended before they reached my row.

The charges were ridiculous for an hour flight and the turbulence was very scary.

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

The flight crew was extremely rude and especially not helpful when our flight was delayed.

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.

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.

Left a few minutes early. Got in 15 minutes early. Very attentive service on board. Very organized boarding.

There’s not much to say about a one hour flight. This is a connection from LA to RNO that I missed the previous night due to a mechanical check delay on my originating flight from JFK to LAX. The short flight itself was fine. Instructions from the pilot and crew were per usual. The coffee was barely lukewarm, which possibly was purposeful so we would down it quickly. Bags were already on carousel upon reaching baggage claim, which was excellent.

Delta continues to set the benchmark for traveler-friendly service with minimal disruption and clear communication within the mainland US (coast to coast). I am consistently pleased to be a Delta customer, and this experience once again met my expectations. There was a brief delay departing from MIA due to a technical issue that required the aircraft to return to the gate. However, the situation was handled professionally and transparently. Fortunately, my planned layover allowed ample buffer time, so the adjustment caused no stress. Overall, another smooth and reassuring experience.

Awesome! On time flight, early arrival, and a complimentary upgrade!

Was forced to check in my small carry on, even though I informed the crew it has very fragile items inside

They double booked seats, the gate staff changed my ticket as I was boarding she went over to the computer and changed it without telling me. She messed up an entire three row section for me and others. Other travelers were outraged but the gate staff were so rude, so condescending saying it wasn't their problem to solve. I would rate this a zero if I could. Will not fly Delta again I'll stick with United and American.

I usually get upgraded so my experience is usually amazing. I did not get upgraded this time - which was fine - but the wifi had issues, the monitors were going in & out, & (though not Delta's fault) one of the gentlemen next to me desperately needed a shower.

I really liked the legroom. I am 6’4”.a at For some reason our seats were not together and using the app to fix it didn’t work. Passengers were nice enough to move for us but you should absolutely ensure a parent sits with their child.

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.

The flight was delayed so we were dead tired, and after that the turbulence was horrible. I was very scared.

Wonderful. Quick boarding. Early departure and we arrived 30 minutes early at our destination. Unfortunately, when you arrive early, there is still a departing aircraft at our gate. We had to park for 30 minutes until the gate was clear. So our early arrival was not really early at the gate. Otherwise it was a quick and smooth flight. Appreciated the efficiency.

Wifi took a while to kick in and we had a maintenance issue that took over 40 mins at the gate in Washington before pulling back

Very good. Because of the delays with my previous flight, I missed my connection, but I was able to book another flight through the United app easily.

Was happy we finally got upgraded in 1st class. The seat getting old. The cushiness need some improvement.

Ineffective communication with United resulted in lost baggage. Their Baggage Tracing counter at MUC was shut down from 11:00-14:15 on my arrival. Undertrained, underinformed staff had me Running all over MUC to find someone to help me to no avail. Staff was rude, unhelpful, and unable to effectively use the systems they did have operational. They refused to contact United in any way or provide any accommodation or other resources while I waited for my luggage. This has destroyed my downstream itinerary. If they had even the slightest visibility I may have been able to reschedule/plan, but again, their staff provided nothing, and did nothing more than their website, which doesn’t even work on a standard phone browser. Miserable failure at all levels that weren’t associated with the operation of the aircraft.

Sat next to a one year old. She crawled all over the place and made me laugh.

The Crew and the food was the worst I ever had in Business Class. First they told us there were no space for carry on. It was plenty of space over our 2 row seats, we had to ask to let us travel with it which was accepted. They were aware that we had to run for the connection due to the previous flight delay. Have us one hour waiting for more customers and not even offer a glass of water. Then started the service and they started to serve other passengers drinks in business and did not offer any drinks until they serve our pre ordered meal and I ask for something to drink. I had to wait until they finished to serve all passengers until Inget something. The crew was the worts I ever had for Business Class in my life.

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

Starlink wifi on the Embraer E175 is an excellent experience. I was able to connect and work from IAD all the way to approach into BTV.

Flight delay for mechanical. Inbound arrived on time. No one said why mechanical delay.

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

Flight boarded, departed and landed on time. Excellent service from flight attendant in FIRST

This was one of the most frustrating travel experiences I've had to date. I had changed my flight day of to this one as it was slated to depart on time. It ended up being so delayed that my original flight took off before this one did. The boarding process began but eventually stopped and everyone had to get off the plane as a problem was identified. The person at the front desk just tried to laugh it off as if this wasn't already a huge inconvenience. From there, we eventually got to board only to sit at the gate for an additional hour because of some additional issue. This was extremely frustrating and caused a lot of stress.

It was a little concerning to hear the ground crew arguing with the flight crew over baggage space. Instead of taking them and checking them, they started checking for space in the first class cabin moving items around like the flight crew didn't know what they were doing. I was embarrassed for them.

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

delayed due to weather. Could not communicate with family since the wifi was broken

I got sick nothing contagious but distressing and the care I received by Kayla? Keighly the flight attendant will be memorable for ever. Thank You

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

Flight delay was communicated before leaving for airport which caused it to be a non-event. Great flight and crew!

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

My flight was originally from SAT to MCO connecting from MCO to ORD. We got diverted to ATL and than Frontier staff there was sooo un helpful first they said they couldn’t give us any accommodation since our flight first got delayed that cancelled and now it’s 221am and I am still in ATL since they said they need to create a new flight my final destination is ORD and I have been delayed twice and cancelled. With no real help the frontier app didn’t work no email updates over all such a horrible experience

There's no seats that lean back with little leg space i wad uncomfortable the entire flight. Your charges for extra baggage is despicable and costly!!

Remind customers of the need to have passport or new ID for boarding.

Flight was canceled. Most upsetting was message from Kayak, stating that the flight was canceled and click with Kayak for details regarding rebook, refund details. THERE'S NO INFORMATION PROVIDED BY KAYAK EXCEPT THAT FLIGHT IS CANCELED. AND NOW THIS SURVEY TO FIND OUT HOW WAS THE FLIGHT !!!!!!!

The flight never took off and we spent 7 hours at the airport

Gate not determined until I got to the airport - hard to plan the trip to the airport.

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

Frontier.. nickel and dime add-ons. Flight late, on time, late again, last minute gate change, arrival gate required a shuttle to the terminal. They sure keep you guessing.. if you like a little chaos and airport anxiety, this is the airline for you!

This is my second time flying with Frontier. My current experience was very favorable. The staff from the gate to the plane was friendly, warm and professional. The food options lacked in my opinion. This area needs some attention in my opinion.

Everything you need to know for your flight from Washington, D.C. to Ontario

Information on your arrival and departure airports