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Ontario

$101+ 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 9/1. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — ONT
Jun 11 — Jun 181
Thu 6/11
Thu 6/18
1 adult, Economy
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Find cheap flights from Washington, D.C. to Ontario with Cheapflights

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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 May 12, 2026.

This Frontier deal was found by Cheapflights users on 5/11. 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 9/16:00 pm
DCA
-
ONT
1 stop8h 49m
Frontier
Wed 9/210:50 am
ONT
-
DCA
1 stop8h 09m
Frontier
Deal found 5/11$210
This Frontier deal was found by Cheapflights users on 5/12. 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 6/29:12 am
IAD
-
ONT
1 stop13h 20m
Frontier
Tue 9/13:34 pm
ONT
-
IAD
1 stop13h 16m
Frontier
Deal found 5/12$210
This Booking.com deal was found by Cheapflights users on 5/9. 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 6/29:12 am
IAD
-
ONT
1 stop9h 32m
Frontier
Wed 6/101:33 pm
ONT
-
IAD
1 stop15h 52m
Frontier
Deal found 5/9$217
This CheapOair deal was found by Cheapflights users on 5/11. 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.
Tue 5/269:12 am
IAD
-
ONT
1 stop25h 52m
Frontier
Tue 6/21:39 pm
ONT
-
IAD
1 stop15h 33m
Frontier
Deal found 5/11$220
This Booking.com deal was found by Cheapflights users on 5/12. 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 6/99:55 am
IAD
-
ONT
1 stop12h 56m
Frontier
Wed 6/173:34 pm
ONT
-
IAD
1 stop13h 51m
Frontier
Deal found 5/12$222
This Frontier deal was found by Cheapflights users on 5/12. 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.
Sat 6/66:00 pm
DCA
-
ONT
1 stop8h 49m
Frontier
Wed 9/26:00 am
ONT
-
DCA
1 stop12h 59m
Frontier
Deal found 5/12$224
This Expedia deal was found by Cheapflights users on 5/12. 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.
Tue 6/29:12 am
IAD
-
ONT
1 stop13h 20m
Frontier
Mon 6/83:30 pm
ONT
-
IAD
1 stop13h 55m
Frontier
Deal found 5/12$224
This Frontier deal was found by Cheapflights users on 5/10. 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.
Mon 6/19:12 am
IAD
-
ONT
1 stop13h 20m
Frontier
Tue 6/91:33 pm
ONT
-
IAD
1 stop15h 52m
Frontier
Deal found 5/10$226
This Expedia deal was found by Cheapflights users on 5/10. 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.
Tue 6/24:29 pm
BWI
-
ONT
1 stop18h 06m
Frontier
Wed 6/38:06 pm
ONT
-
BWI
1 stop21h 12m
Frontier
Deal found 5/10$230
This Frontier deal was found by Cheapflights users on 5/10. 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 9/16:00 pm
DCA
-
ONT
1 stop8h 49m
Frontier
Wed 9/96:00 am
ONT
-
DCA
1 stop12h 58m
Frontier
Deal found 5/10$230
This Frontier deal was found by Cheapflights users on 5/11. 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.
Sat 7/49:35 am
IAD
-
ONT
1 stop8h 33m
Frontier
Wed 7/83:40 pm
ONT
-
IAD
1 stop13h 40m
Frontier
Deal found 5/11$230
This Booking.com deal was found by Cheapflights users on 5/8. 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.
Mon 6/19:12 am
IAD
-
ONT
1 stop8h 57m
Frontier
Wed 6/103:34 pm
ONT
-
IAD
1 stop13h 51m
Frontier
Deal found 5/8$231

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 May 12, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$210
(Frontier)

One-way from

$101
(Super.com)

Popular in

April

Cheapest in

January

Average price

$429

Good round-trip deal

$378 or less

Good one-way deal

$276 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. 14% potential increase in price ($64 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($13 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 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 May 12, 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

Thu 5/28

5:59 pm-11:34 pm

1 stop8h 35m

Ontario

Tue 6/2

10:00 pm-9:11 am

1 stop8h 11m

$321

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 5/27

6:00 am-3:09 pm

1 stop12h 09m

Ontario

Tue 6/2

7:41 pm-7:34 am

1 stop8h 53m

$341

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 7/23

3:02 pm-9:50 pm

1 stop9h 48m

Ontario

Thu 8/6

10:00 pm-9:19 am

1 stop8h 19m

$356

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Thu 8/27

9:12 am-6:29 pm

2 stops12h 17m

Ontario

Mon 8/31

6:00 am-8:19 pm

2 stops11h 19m

$366

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Thu 10/22

1:45 pm-6:18 pm

1 stop7h 33m

Ontario

Sat 10/24

5:50 pm-8:44 am

2 stops11h 54m

$371

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Tue 8/11

2:45 pm-11:34 pm

2 stops11h 49m

Ontario

Mon 8/17

10:00 pm-9:10 am

1 stop8h 10m

$373

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Sat 8/8

5:42 pm-10:51 pm

1 stop8h 09m

Ontario

Mon 8/10

1:18 pm-12:45 am

1 stop8h 27m

$414

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Fri 7/10

6:00 am-10:38 am

1 stop7h 38m

Ontario

Wed 7/15

11:48 am-10:48 pm

1 stop8h 00m

$420

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 8/6

6:00 am-10:42 am

1 stop7h 42m

Ontario

Thu 8/27

9:43 am-12:33 am

2 stops11h 50m

$425

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Fri 7/10

4:30 pm-10:35 pm

2 stops9h 05m

Ontario

Tue 7/14

5:15 am-6:15 pm

2 stops10h 00m

$450

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/10

Showing 1-10 of 60 resultsSorted by cheapest first
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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 May.
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?

The best time to book flights from Washington, D.C. to Ontario is 7 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, May is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $53). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $219). 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 May 12, 2026.

It’s typically best to fly out from Washington, D.C. to Ontario in the evening. Doing so could potentially save you 28% 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 May 12, 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
7.9
Good
4,296 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
7.9
Good
4,296 reviews
Southwest
7.9
Good
4,296 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
8,450 reviews
Southwest
7.9
Good
4,296 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
9,706 reviews
Southwest
7.9
Good
4,296 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
11,662 reviews
Southwest
7.9
Good
4,296 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

7.9

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
5.6
Fair
2,952 reviews
Southwest
7.9
Good
4,296 reviews

Comfort

8.0

Crew

8.6

Food

7.0

Boarding

8.1

Entertainment

7.5

Overall

7.9

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 $321, Delta can have you in Ontario from Washington, D.C. in 7h 42m. Washington, D.C. and Ontario are separated by a distance of 2258 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 67% 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 ($93), United Airlines ($139), and Southwest ($158).

  • 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 Washington, D.C. Reagan-National - Ontario or Baltimore/Washington - 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, May is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $53). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $219). 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

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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 May 12, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$125Average$292FlexibilityNo cancel feeOn-time62%
DeltaCheapest$192Average$444FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$256Average$516FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$278Average$490FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$284Average$462FlexibilityNo cancel feeOn-time69%

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