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Ontario

$96+ 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 5/14. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — ONT
May 6 — May 131
Tue 5/6
Tue 5/13
1 adult, Economy
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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Washington, D.C. to Ontario are usually found in August or October, booked 78 days in advance, depart on a Tuesday or Saturday and return on a Wednesday

Cheap 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 1, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$208
(Frontier)

One-way from

$96
(Trip.com)

Popular in

June

Cheapest in

August

Average price

$336

Good round-trip deal

$469 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.
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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. 1% potential increase in price ($6 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in May 2025
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Price to beat on a round-trip flight from Washington, D.C. (WAS) to Ontario.
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Find 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 1, 2025.

This CheapOair deal was found by Cheapflights users on 4/28. 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 5/285:23 pmBWI - ONT
1 stop18h 52mFrontier
Fri 5/3012:59 amONT - BWI
1 stop12h 54mFrontier
Deal found 4/28$201
This Trip.com deal was found by Cheapflights users on 4/30. 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.
Tue 5/67:00 amDCA - ONT
1 stop19h 59mFrontier
Mon 6/212:59 amONT - DCA
1 stop8h 01mFrontier
Deal found 4/30$214
This Gotogate deal was found by Cheapflights users on 4/30. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/37:45 amIAD - ONT
1 stop26h 39mFrontier
Mon 5/510:52 amONT - IAD
1 stop16h 39mFrontier
Deal found 4/30$216
This Alaska Airlines deal was found by Cheapflights users on 4/30. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/49:00 amIAD - ONT
1 stop9h 50mAlaska Airlines
Tue 6/107:20 pmONT - IAD
1 stop9h 16mAlaska Airlines
Deal found 4/30$292
This Expedia deal was found by Cheapflights users on 4/30. 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.
Mon 6/25:20 pmBWI - ONT
1 stop9h 30mMultiple Airlines
Sat 6/74:45 pmONT - BWI
1 stop10h 44mMultiple Airlines
Deal found 4/30$318
This American Airlines deal was found by Cheapflights users on 4/30. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/217:18 pmBWI - ONT
1 stop7h 25mAmerican Airlines
Wed 5/2810:40 pmONT - BWI
1 stop8h 16mAmerican Airlines
Deal found 4/30$319
This Hawaiian Airlines deal was found by Cheapflights users on 4/30. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/49:00 amIAD - ONT
1 stop9h 50mHawaiian Airlines
Tue 6/107:20 pmONT - IAD
1 stop9h 16mHawaiian Airlines
Deal found 4/30$326
This Delta deal was found by Cheapflights users on 4/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/266:59 amDCA - ONT
1 stop7h 09mDelta
Wed 7/97:05 amONT - DCA
1 stop7h 18mDelta
Deal found 4/29$327
This Delta deal was found by Cheapflights users on 4/30. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/47:45 amIAD - ONT
1 stop9h 30mDelta
Sat 6/712:18 pmONT - IAD
1 stop8h 17mDelta
Deal found 4/30$327
This United Airlines deal was found by Cheapflights users on 4/29. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/72:47 pmDCA - ONT
1 stop10h 13mUnited Airlines
Tue 5/136:08 amONT - DCA
1 stop6h 54mUnited Airlines
Deal found 4/29$328
This Alaska Airlines deal was found by Cheapflights users on 4/29. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/37:49 amBWI - ONT
1 stop11h 01mAlaska Airlines
Tue 6/104:45 pmONT - BWI
1 stop10h 44mAlaska Airlines
Deal found 4/29$336
This Southwest deal was found by Cheapflights users on 4/29. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/78:55 pmBWI - ONT
Nonstop5h 20mSouthwest
Mon 6/99:20 pmONT - BWI
Nonstop4h 50mSouthwest
Deal found 4/29$337

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 1, 2025.
Use the filters below to find and compare flights from Washington, D.C. to Ontario that are best for you.

Fly from

Washington, D.C.

Fly to

Ontario

Route

Depart

Return

Price

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Wed 5/28

5:23 pm-9:15 am

1 stop18h 52m

Ontario

Fri 5/30

12:59 am-4:53 pm

1 stop12h 54m

$201

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Mon 5/12

7:00 am-11:15 am

1 stop7h 15m

Ontario

Fri 5/16

12:16 pm-9:59 pm

1 stop6h 43m

$215

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 5/15

7:31 am-5:45 pm

1 stop13h 14m

Ontario

Tue 5/20

1:08 pm-6:31 am

1 stop14h 23m

$216

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 6/4

9:00 am-3:50 pm

1 stop9h 50m

Ontario

Wed 6/11

7:20 pm-7:36 am

1 stop9h 16m

$292

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Mon 6/2

5:20 pm-11:50 pm

1 stop9h 30m

Ontario

Sat 6/7

4:45 pm-6:29 am

1 stop10h 44m

$318

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Wed 5/21

7:18 pm-11:43 pm

1 stop7h 25m

Ontario

Wed 5/28

10:40 pm-9:56 am

1 stop8h 16m

$319

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 5/14

8:20 am-12:38 pm

1 stop7h 18m

Ontario

Wed 5/14

6:48 pm-7:19 am

1 stop9h 31m

$322

Washington, D.C.Ontario

DCA - ONT

DCAONT

Washington, D.C. Reagan-National

Mon 5/26

6:59 am-11:08 am

1 stop7h 09m

Ontario

Fri 7/11

10:05 pm-9:09 am

1 stop8h 04m

$327

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 7/15

6:00 am-10:30 am

1 stop7h 30m

Ontario

Wed 7/23

5:50 pm-5:57 am

1 stop9h 07m

$327

BaltimoreOntario

BWI - ONT

BWIONT

Baltimore/Washington

Tue 6/3

7:49 am-3:50 pm

1 stop11h 01m

Ontario

Tue 6/10

4:45 pm-6:29 am

1 stop10h 44m

$336

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/29

Showing 1-10 of 43 results
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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*2 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
Kiwi.comPrice 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 Mytrip to be most consistent on Cheapflights vs. Mytrip Users can find the same prices on Washington, D.C.-Ontario flight deals on Cheapflights vs. Mytrip >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 Mytrip the most. Mytrip 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 April 25, 2025.

The best time to book flights from Washington, D.C. to Ontario is 77 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, August is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $246). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $328). 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 1, 2025.

It’s typically best to fly out from Washington, D.C. to Ontario in the afternoon. Doing so could potentially save you 16% on the flight price compared to flying in the evening, which is usually more expensive.

What is the cheapest day to fly from Washington, D.C. to Ontario?

Use this chart to determine the cheapest time to fly round-trip from Washington, D.C. to Ontario. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Washington, D.C. to Ontario flight should consider departing on Saturday evenings when fares are most often at their lowest. Friday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

Plan your trip to Ontario by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

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 1, 2025.
See what other customers who have flown with Alaska Airlines, Southwest and Delta from Washington, D.C. to Ontario have to say. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,972 reviews

Comfort

7.9

Food

7.1

Crew

8.5

Entertainment

7.1

Boarding

8.1

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
9,972 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Comfort

7.9

Food

7.1

Crew

8.5

Entertainment

7.1

Boarding

8.1

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,294 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Comfort

7.9

Food

7.1

Crew

8.5

Entertainment

7.1

Boarding

8.1

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,934 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Comfort

7.9

Food

7.1

Crew

8.5

Entertainment

7.1

Boarding

8.1

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.9
Good
2,408 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Comfort

7.9

Food

7.1

Crew

8.5

Entertainment

7.1

Boarding

8.1

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,696 reviews
Alaska Airlines
8.0
Very good
9,972 reviews

Comfort

7.9

Food

7.1

Crew

8.5

Entertainment

7.1

Boarding

8.1

Overall

8.0

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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.

  • 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 $208. Other airlines that can offer you cheap pricing are Alaska Airlines, from $292, and American Airlines, from $319. Users have found that Frontier is 46% 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 ($96), Alaska Airlines ($138), and Delta ($162).

  • 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, August is the cheapest month in which you can book a flight from Washington, D.C. to Ontario (average of $246). Flying from Washington, D.C. to Ontario in March is currently the most expensive (average of $328). 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

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Alternative routes for Washington, D.C. to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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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 1, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$150Average$260FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$195Average$484FlexibilityNo cancel feeOn-time69%
DeltaCheapest$286Average$435FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$286Average$473FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$326Average$511FlexibilityNo cancel feeOn-time63%

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