HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$79+ Cheap flights from Washington, D.C. (WAS) to Ontario (ONT)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/25. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — ONT
Apr 27 — May 41
Mon 4/27
Mon 5/4
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Washington, D.C. to Ontario with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Washington, D.C. to Ontario

Cheapest flights from Washington, D.C. to Ontario
Explore the most affordable flight options available from Washington, D.C. to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 28, 2026.

This Kiwi.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/148:00 am
DCA
-
ONT
1 stop18h 55m
Frontier
Fri 4/1712:59 am
ONT
-
DCA
1 stop9h 01m
Frontier
Deal found 3/24$158
This Frontier deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/213:06 pm
BWI
-
ONT
1 stop8h 33m
Frontier
Fri 5/18:26 am
ONT
-
BWI
1 stop8h 43m
Frontier
Deal found 3/27$160
This Expedia deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/186:00 pm
DCA
-
ONT
1 stop8h 55m
Frontier
Wed 4/2212:59 am
ONT
-
DCA
1 stop9h 01m
Frontier
Deal found 3/27$160
This Booking.com deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/95:34 pm
BWI
-
ONT
1 stop17h 01m
Frontier
Sun 5/108:06 pm
ONT
-
BWI
1 stop21h 17m
Frontier
Deal found 3/23$162
This Booking.com deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:00 am
DCA
-
ONT
1 stop18h 55m
Frontier
Mon 4/2012:59 am
ONT
-
DCA
1 stop18h 00m
Frontier
Deal found 3/23$162
This Booking.com deal was found by Cheapflights users on 3/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/283:06 pm
BWI
-
ONT
1 stop8h 16m
Frontier
Sun 5/38:21 am
ONT
-
BWI
1 stop23h 59m
Frontier
Deal found 3/24$167
This Booking.com deal was found by Cheapflights users on 3/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/197:59 am
DCA
-
ONT
1 stop26h 32m
Frontier
Wed 4/2212:59 am
ONT
-
DCA
1 stop9h 00m
Frontier
Deal found 3/25$167
This Trip.com deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/186:00 pm
DCA
-
ONT
1 stop8h 55m
Frontier
Fri 4/2412:59 am
ONT
-
DCA
1 stop9h 00m
Frontier
Deal found 3/27$168
This CheapOair deal was found by Cheapflights users on 3/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:00 am
DCA
-
ONT
1 stop26h 31m
Frontier
Fri 4/175:33 pm
ONT
-
DCA
1 stop16h 27m
Frontier
Deal found 3/25$171
This Booking.com deal was found by Cheapflights users on 3/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/65:17 pm
BWI
-
ONT
1 stop17h 18m
Frontier
Fri 5/88:06 pm
ONT
-
BWI
1 stop21h 17m
Frontier
Deal found 3/27$172
This Mytrip deal was found by Cheapflights users on 3/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/218:00 am
DCA
-
ONT
1 stop18h 55m
Frontier
Thu 4/2312:59 am
ONT
-
DCA
1 stop18h 00m
Frontier
Deal found 3/23$172
This Frontier deal was found by Cheapflights users on 3/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/141:59 pm
DCA
-
ONT
1 stop12h 56m
Frontier
Sun 4/1912:59 am
ONT
-
DCA
1 stop9h 01m
Frontier
Deal found 3/25$180

Find flight deals from Washington, D.C. to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Washington, D.C. (WAS) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 28, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$158
(Kiwi.com)

One-way from

$79
(Super.com)

Popular in

November

Cheapest in

January

Average price

$379

Good round-trip deal

$398 or less

Good one-way deal

$239 or less
Provider with most accurate pricing for Washington, D.C. (WAS)-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. (WAS)-Ontario flights.
Search Deals
From Washington, D.C. (WAS) to Ontario
Search Deals
One-way flight from Washington, D.C. (WAS) to Ontario
Search Deals
Highest demand for flights based on searches. 8% potential increase in price ($32 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals
Price to beat on a round-trip flight from Washington, D.C. (WAS) to Ontario.
Search Deals
Price to beat on a one-way flight from Washington, D.C. (WAS) to Ontario.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Washington, D.C. to Ontario that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2026.
Use the filters below to find and compare flights from Washington, D.C. to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Sat 4/18

11:00 am-9:00 pm

2 stops13h 00m

Ontario

Wed 4/22

12:49 pm-11:41 pm

1 stop7h 52m

$340

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Mon 4/20

5:55 am-12:10 pm

2 stops9h 15m

Ontario

Mon 4/27

3:00 pm-12:20 am

1 stop6h 20m

$387

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Mon 4/20

12:45 pm-3:15 pm

Nonstop5h 30m

Ontario

Mon 4/27

3:00 pm-12:25 am

1 stop6h 25m

$397

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Tue 5/26

5:05 pm-9:50 pm

1 stop7h 45m

Ontario

Tue 6/2

9:55 pm-5:40 am

Nonstop4h 45m

$398

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Sat 4/18

7:20 am-12:14 pm

1 stop7h 54m

Ontario

Mon 4/20

10:15 pm-9:15 am

1 stop8h 00m

$399

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 5/7

5:55 am-11:20 am

2 stops8h 25m

Ontario

Tue 5/12

10:55 am-11:40 pm

2 stops9h 45m

$404

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Tue 4/14

3:40 pm-10:10 pm

2 stops9h 30m

Ontario

Mon 4/20

9:55 pm-8:55 am

2 stops8h 00m

$414

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Fri 5/1

7:00 am-11:13 am

1 stop31h 13m

Ontario

Mon 5/4

10:15 pm-9:15 am

1 stop8h 00m

$430

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Fri 5/8

2:00 pm-8:45 pm

1 stop9h 45m

Ontario

Sat 5/9

8:40 am-8:45 pm

2 stops9h 05m

$432

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Wed 4/15

11:00 am-9:00 pm

2 stops13h 00m

Ontario

Sat 4/18

12:49 pm-7:15 am

2 stops15h 26m

$436

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/24

Showing 1-10 of 60 resultsSorted by cheapest first
1
2
3
...
6

Compare providers for flights from Washington, D.C. to Ontario

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Washington, D.C. to Ontario in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C.-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C.-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C.-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C.-Ontario flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C.-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Washington, D.C. to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Washington, D.C. with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

How far ahead should I book a flight from Washington, D.C. to Ontario?

Use this chart to determine the optimal time to book a round-trip flight from Washington, D.C. to Ontario. Price data was last updated on March 13, 2026.

The best time to book flights from Washington, D.C. to Ontario is 38 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from Washington, D.C. to Ontario?

Currently, November is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $77). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $188). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from WAS to ONT?

Find hourly flight availability from Washington, D.C. to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 28, 2026.

It’s typically best to fly out from Washington, D.C. to Ontario in the evening. Doing so could potentially save you 24% on the flight price compared to flying in the afternoon, which is usually more expensive.

How much does it cost to fly round-trip from Washington, D.C. to Ontario?

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated March 28, 2026.
Read through reviews of airlines operating flights from Washington, D.C. to Ontario, such as Southwest,Delta, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,333 reviews

Food

7.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Southwest
8.0
Very good
4,333 reviews
Southwest
8.0
Very good
4,333 reviews

Food

7.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Delta
7.9
Good
8,356 reviews
Southwest
8.0
Very good
4,333 reviews

Food

7.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
United Airlines
7.4
Good
9,499 reviews
Southwest
8.0
Very good
4,333 reviews

Food

7.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
American Airlines
7.1
Good
11,520 reviews
Southwest
8.0
Very good
4,333 reviews

Food

7.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Frontier
5.7
Fair
3,013 reviews
Southwest
8.0
Very good
4,333 reviews

Food

7.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Overall

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Related info for your journey

Find useful and relevant information for your journey from Washington, D.C. to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Ontario from Washington, D.C.?

    Located just 3.1 mi from the city center, Ontario is the airport most travelers will use when flying to Ontario from Washington, D.C.. Booking flights from Washington, D.C. to Ontario (ONT) should be relatively easy as there are 0 daily inbound flights from Washington, D.C. from 5 different airlines.

  • How long is the flight from Washington, D.C. to Ontario?

    For as low as $160, Frontier can have you in Ontario from Washington, D.C. in 8h 33m. Washington, D.C. and Ontario are separated by a distance of 2276 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Washington, D.C. to Ontario round-trip?

    Cheapflights users have booked flights from Washington, D.C. to Ontario round-trip from $125. Other airlines that can offer you cheap pricing are Delta, from $213, and American Airlines, from $256. Users have found that Frontier is 66% cheaper than the other options available to this destination.

  • What are the cheapest airlines to fly from Washington, D.C. to Ontario one-way?

    The cheapest airlines for a one-way flight from Washington, D.C. to Ontario are Frontier ($89), United Airlines ($139), and Delta ($143).

  • What are the most popular routes from Washington, D.C. to Ontario?

    The most popular route from Washington, D.C. to Ontario is Washington, D.C. Dulles Intl - Ontario. You may also consider Baltimore/Washington - Ontario or Washington, D.C. Reagan-National - Ontario.

  • Can I find deals for flights from Washington, D.C. to Ontario that include hotel bookings?

    Yes. In addition to deals on Washington, D.C. to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Washington, D.C. to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Washington, D.C. to Ontario.

  • Can I find deals for business class flights from Washington, D.C. to Ontario?

    Yes. Cheapflights offers flight deals from Washington, D.C. to Ontario by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, November is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $77). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $188). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 5 airlines flying from Washington, D.C. to Ontario

Discover the top 5 airlines that operate flights from Washington, D.C. to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$125Average$281FlexibilityNo cancel feeOn-time62%
DeltaCheapest$213Average$419FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$222Average$438FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$256Average$509FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$278Average$471FlexibilityNo cancel feeOn-time63%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.