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

Our cheapest airline available from Washington, D.C. Dulles Intl Airport to Ontario is Frontier. Our recent data shows that you can find tickets from as low as $215 on this airline. Additional options worth looking into are Alaska Airlines and Hawaiian Airlines, starting at $292 and $326 round-trip. Frontier is priced at 53% lower than the current average price of a flight leaving 3 months from now.

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

The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $96. However, be on the lookout for offers from Alaska Airlines and Hawaiian Airlines, as they are both options that can get you from Washington, D.C. Dulles Intl Airport to Ontario for a low price.

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

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

What are the most popular airlines that fly from Washington, D.C. Dulles Intl Airport to Ontario?

American Airlines, Delta and United Airlines are the most popular airlines when flying from Washington, D.C. Dulles Intl Airport to Ontario.

What is the cheapest day to fly round-trip from Washington, D.C. Dulles Intl Airport to Ontario?

Flights from Washington, D.C. Dulles Intl Airport to Ontario are found to be more expensive on Friday. This shouldn't discourage you from searching as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to Ontario.

What is the cheapest month to fly from Washington, D.C. Dulles Intl Airport to Ontario?

September can be a great time to fly to Ontario from Washington, D.C. Dulles Intl Airport with a flight ticket averaging about $362. Cheapflights users have found deals in the month of September for as cheap as $121. The most expensive prices can be found in the month of December.

Most accurate provider : When it comes to deals on Washington, D.C. Dulles Intl Airport-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. Dulles Intl Airport-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Ontario flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Washington, D.C. Dulles Intl Airport-Ontario flights, Cheapflights users trust eDreams the most. eDreams 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. Dulles Intl Airport-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

Ontario (ONT), located 3.1 mi from the city center, is the airport you fly into when you book flights from Washington, D.C. Dulles Intl to Ontario. 4 airlines have flights to Ontario from Washington, D.C. Dulles Intl on a regular basis. Booking flights from Washington, D.C. Dulles Intl to Ontario should not be difficult; the airport handles an average of 0 inbound flights from Washington, D.C. Dulles Intl per day.

Can I find deals for flights from Dulles Intl to Ontario that include hotel bookings?

Yes. In addition to deals on Dulles Intl to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Dulles Intl to Ontario?

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

Can I find deals for business class flights from Dulles Intl to Ontario?

Yes. Cheapflights offers flight deals from Dulles Intl 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.

$96+ Flights from Washington, D.C. Dulles Intl Airport to Ontario

Q: How far in advance should I book a flight from Washington, D.C. Dulles Intl Airport to Ontario?

To save on the cost of your flight from Washington, D.C. Dulles Intl Airport to Ontario, book at least 31 days before your planned departure. Booking around this time can save you about 84% on the cost of this flight compared to booking a flight leaving this week. We have found prices from $377 if you need a flight within two weeks. For flights within the next 72 hours, you can find tickets from as low as $605.

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Find cheap flights from Dulles Intl 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.

Cheapflights Tip: The best prices from Washington, D.C. Dulles Intl to Ontario are usually found in September or April, booked 76 days in advance, depart on a Thursday or Tuesday and return on a Thursday

Cheap flight deals from Dulles Intl to Ontario

Most accurate provider	FlightHub 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$215 (Trip.com)
One-way from	$96 (Flightnetwork)
Popular in	March
Cheapest in	September
Average price	$376

Provider with most accurate pricing for Washington, D.C. Dulles Intl-Ontario flight deals.

Search Deals

Provider most trusted by Cheapflights users for Washington, D.C. Dulles Intl-Ontario flights.

Search Deals

From Washington, D.C. Dulles Intl to Ontario

Search Deals

One-way flight from Washington, D.C. Dulles Intl to Ontario

Search Deals

Highest demand for flights based on searches. 6% potential increase in price ($34 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 4% potential price decrease ($18 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in April 2025

Search Deals

Find flight deals from Dulles Intl to Ontario

Cheapest flights from Dulles Intl to Ontario
Explore the most affordable flight options available from Dulles Intl to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

Tue 5/67:45 amIAD - ONT

1 stop7h 23mFrontier

Wed 5/71:08 pmONT - IAD

1 stop14h 23mFrontier

Deal found 4/29

$215

Tue 6/39:00 amIAD - ONT

1 stop9h 50mAlaska Airlines

Tue 6/107:20 pmONT - IAD

1 stop9h 16mAlaska Airlines

Deal found 4/29

$292

Wed 5/148:20 amIAD - ONT

1 stop7h 18mUnited Airlines

Wed 5/146:48 pmONT - IAD

1 stop9h 31mUnited Airlines

Deal found 4/29

$322

Tue 6/39:00 amIAD - ONT

1 stop9h 50mHawaiian Airlines

Tue 6/107:20 pmONT - IAD

1 stop9h 16mHawaiian Airlines

Deal found 4/29

$326

Mon 7/145:20 pmIAD - ONT

1 stop8h 07mDelta

Fri 7/2510:05 pmONT - IAD

1 stop9h 06mDelta

Deal found 4/29

$327

Tue 6/31:59 pmIAD - ONT

2 stops10h 58mAmerican Airlines

Tue 6/107:02 pmONT - IAD

2 stops10h 36mAmerican Airlines

Deal found 4/29

$337

Mon 6/25:35 pmIAD - ONT

1 stop8h 25mSouthwest

Thu 6/1210:00 amONT - IAD

2 stops10h 30mSouthwest

Deal found 4/29

$432

Thu 5/110:00 amIAD - ONT

1 stop10h 30mMultiple Airlines

Mon 5/52:28 pmONT - IAD

1 stop13h 03mMultiple Airlines

Deal found 4/29

$547

Best flights from Dulles Intl to Ontario
Discover carefully curated flight deals from Dulles Intl to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 29, 2025.

Tue 5/67:45 amIAD - ONT

1 stop7h 23mFrontier

Wed 5/71:08 pmONT - IAD

1 stop14h 23mFrontier

Deal found 4/29

$215

Thu 5/299:00 amIAD - ONT

1 stop9h 50mAlaska Airlines

Tue 6/37:20 pmONT - IAD

1 stop9h 16mAlaska Airlines

Deal found 4/27

$292

Tue 6/39:00 amIAD - ONT

1 stop9h 50mHawaiian Airlines

Tue 6/107:20 pmONT - IAD

1 stop9h 16mHawaiian Airlines

Deal found 4/28

$326

Sat 5/317:45 amIAD - ONT

1 stop9h 30mDelta

Sat 6/712:18 pmONT - IAD

1 stop8h 17mDelta

Deal found 4/28

$327

Fri 6/65:18 pmIAD - ONT

1 stop8h 08mUnited Airlines

Tue 6/105:10 amONT - IAD

1 stop7h 24mUnited Airlines

Deal found 4/28

$347

Thu 5/86:17 amIAD - ONT

1 stop10h 35mAmerican Airlines

Mon 6/1612:59 amONT - IAD

1 stop7h 01mAmerican Airlines

Deal found 4/28

$364

Mon 6/25:35 pmIAD - ONT

1 stop8h 25mSouthwest

Sat 6/711:00 amONT - IAD

2 stops9h 30mSouthwest

Deal found 4/28

$432

Last-minute flights from Dulles Intl to Ontario
Discover last-minute flight deals from Dulles Intl to Ontario. Data last updated April 29, 2025 and is based on user searches.

Mon 5/56:30 amIAD - ONT

1 stop12h 02mAlaska Airlines

Tue 8/267:22 pmONT - IAD

1 stop9h 10mAlaska Airlines

Deal found 4/28

$310

Mon 5/52:10 pmIAD - ONT

2 stops11h 50mSouthwest

Sat 5/101:50 pmONT - IAD

1 stop6h 25mSouthwest

Deal found 4/28

$469

Mon 5/56:30 amIAD - ONT

1 stop12h 02mHawaiian Airlines

Wed 5/1411:46 amONT - IAD

1 stop9h 12mHawaiian Airlines

Deal found 4/28

$488

Tue 5/67:45 amIAD - ONT

1 stop7h 23mFrontier

Wed 5/71:08 pmONT - IAD

1 stop14h 23mFrontier

Deal found 4/29

$215

Wed 5/74:00 pmIAD - ONT

1 stop9h 00mUnited Airlines

Sat 5/105:05 amONT - IAD

1 stop7h 31mUnited Airlines

Deal found 4/28

$429

Thu 5/86:17 amIAD - ONT

1 stop10h 35mAmerican Airlines

Mon 6/1612:59 amONT - IAD

1 stop7h 01mAmerican Airlines

Deal found 4/28

$364

Mon 5/1210:25 pmIAD - ONT

1 stop17h 13mMultiple Airlines

Tue 5/134:29 pmONT - IAD

1 stop12h 14mMultiple Airlines

Deal found 4/28

$1,929

Wed 5/289:00 amIAD - ONT

1 stop9h 50mHawaiian Airlines

Mon 6/211:51 amONT - IAD

1 stop9h 08mHawaiian Airlines

Deal found 4/28

$457

Thu 5/299:00 amIAD - ONT

1 stop9h 50mAlaska Airlines

Tue 6/37:20 pmONT - IAD

1 stop9h 16mAlaska Airlines

Deal found 4/27

$292

Fri 5/306:35 amIAD - ONT

1 stop8h 56mUnited Airlines

Mon 6/21:33 pmONT - IAD

1 stop8h 01mUnited Airlines

Deal found 4/29

$427

Sat 5/317:45 amIAD - ONT

1 stop9h 30mDelta

Sat 6/712:18 pmONT - IAD

1 stop8h 17mDelta

Deal found 4/28

$327

One-way flights from Dulles Intl to Ontario
Search for one-way flight options from Dulles Intl to Ontario. Find affordable one-way fares based on user searches. Data last updated April 29, 2025.

Wed 5/147:45 amIAD - ONT

1 stop7h 23mFrontier

Deal found 4/29

$96

Tue 6/39:00 amIAD - ONT

1 stop9h 50mAlaska Airlines

Deal found 4/28

$146

Tue 6/39:00 amIAD - ONT

1 stop9h 50mHawaiian Airlines

Deal found 4/29

$163

Wed 6/116:00 amIAD - ONT

1 stop7h 57mDelta

Deal found 4/29

$164

Sun 6/156:30 amIAD - ONT

1 stop8h 44mUnited Airlines

Deal found 4/29

$184

Wed 7/97:25 amIAD - ONT

2 stops11h 10mSouthwest

Deal found 4/29

$201

Thu 5/156:17 amIAD - ONT

2 stops12h 32mAmerican Airlines

Deal found 4/28

$206

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Fri 5/9

7:45 am-1:16 pm

1 stop8h 31m

Ontario

Sun 5/11

2:28 pm-6:31 am

1 stop13h 03m

$218

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 5/29

9:00 am-3:50 pm

1 stop9h 50m

Ontario

Tue 6/3

7:20 pm-7:36 am

1 stop9h 16m

$292

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 6/3

9:00 am-3:50 pm

1 stop9h 50m

Ontario

Tue 6/10

7:20 pm-7:36 am

1 stop9h 16m

$326

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 6/11

6:00 am-10:57 am

1 stop7h 57m

Ontario

Fri 6/13

3:09 pm-5:59 am

1 stop11h 50m

$327

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 6/3

5:02 am-11:50 am

2 stops9h 48m

Ontario

Tue 6/10

10:28 pm-8:38 am

1 stop7h 10m

$332

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Fri 6/6

5:18 pm-10:26 pm

1 stop8h 08m

Ontario

Tue 6/10

5:10 am-3:34 pm

1 stop7h 24m

$347

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Mon 6/2

5:35 pm-11:00 pm

1 stop8h 25m

Ontario

Sat 6/7

11:00 am-11:30 pm

2 stops9h 30m

$432

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Sat 9/13

8:20 am-8:33 pm

2 stops15h 13m

Ontario

Sat 9/27

7:17 pm-7:32 am

1 stop9h 15m

$632

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 5/13

7:45 am-12:08 pm

1 stop7h 23m

$97

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Wed 8/6

6:30 am-2:46 pm

1 stop11h 16m

$146

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/29

Showing 1-10 of 15 results

Compare providers for flights from Dulles Intl to Ontario

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to Ontario in April.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*2 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Priceline	Price Accuracy2 stars	Trust Score*3 stars
JustAirTicket	Price Accuracy-	Trust 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. Dulles Intl Airport-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. Dulles Intl Airport-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Ontario flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Ontario flights, Cheapflights users trust eDreams the most. eDreams 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. Dulles Intl Airport-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 Dulles Intl to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Dulles Intl 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. Dulles Intl Airport to Ontario

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

The best time to book flights from Washington, D.C. Dulles Intl Airport to Ontario is 75 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. Dulles Intl Airport to Ontario?

Currently, August is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Ontario (average of $246). Flying from Washington, D.C. Dulles Intl Airport 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 IAD to ONT?

It’s typically best to fly out from Washington, D.C. Dulles Intl Airport to Ontario in the morning. Doing so could potentially save you 30% on the flight price compared to flying at noon, which is usually more expensive.

Rainfall in Ontario 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

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

Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta from Washington, D.C. to Ontario. 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

9,961 reviews

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

9,961 reviews

Alaska Airlines

8.0

Very good

9,961 reviews

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

4,295 reviews

Alaska Airlines

8.0

Very good

9,961 reviews

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

7,929 reviews

Alaska Airlines

8.0

Very good

9,961 reviews

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

2,405 reviews

Alaska Airlines

8.0

Very good

9,961 reviews

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

9,961 reviews

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

What airport do you fly into for flights to Ontario from Washington, D.C. Dulles Intl?
Ontario (ONT), located 3.1 mi from the city center, is the airport you fly into when you book flights from Washington, D.C. Dulles Intl to Ontario. 4 airlines have flights to Ontario from Washington, D.C. Dulles Intl on a regular basis. Booking flights from Washington, D.C. Dulles Intl to Ontario should not be difficult; the airport handles an average of 0 inbound flights from Washington, D.C. Dulles Intl per day.
What are the cheapest airlines flying from Washington, D.C. Dulles Intl Airport to Ontario round-trip?
Our cheapest airline available from Washington, D.C. Dulles Intl Airport to Ontario is Frontier. Our recent data shows that you can find tickets from as low as $215 on this airline. Additional options worth looking into are Alaska Airlines and Hawaiian Airlines, starting at $292 and $326 round-trip. Frontier is priced at 53% lower than the current average price of a flight leaving 3 months from now.
What are the cheapest airlines to fly from Washington, D.C. Dulles Intl Airport to Ontario one-way?
The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $96. However, be on the lookout for offers from Alaska Airlines and Hawaiian Airlines, as they are both options that can get you from Washington, D.C. Dulles Intl Airport to Ontario for a low price.
Can I find deals for flights from Dulles Intl to Ontario that include hotel bookings?
Yes. In addition to deals on Dulles Intl to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Dulles Intl to Ontario?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to Ontario.
Can I find deals for business class flights from Dulles Intl to Ontario?
Yes. Cheapflights offers flight deals from Dulles Intl 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. Dulles Intl Airport to Ontario?
Currently, August is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Ontario (average of $246). Flying from Washington, D.C. Dulles Intl Airport 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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Other flights to Ontario

Top 4 airlines flying from Dulles Intl to Ontario

Airline	Cheapest	Average	Flexibility	On-time
American Airlines	Cheapest$286	Average$377	FlexibilityNo cancel fee	On-time71%
Delta	Cheapest$286	Average$387	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$314	Average$497	FlexibilityNo cancel fee	On-time69%
Southwest	Cheapest$326	Average$535	FlexibilityNo cancel fee	On-time63%

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$96+ Cheap flights from Dulles Intl (IAD) 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.

Find cheap flights from Dulles Intl to Ontario with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Washington, D.C. Dulles Intl to Ontario are usually found in September or April, booked 76 days in advance, depart on a Thursday or Tuesday and return on a Thursday

Cheap flight deals from Dulles Intl to Ontario

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Find flight deals from Dulles Intl to Ontario

Cheapest flights from Dulles Intl to OntarioExplore the most affordable flight options available from Dulles Intl to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

Explore the most affordable flight options available from Dulles Intl to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

Cheapflights Fare Finder

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

Compare providers for flights from Dulles Intl 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 Dulles Intl to Ontario in April.

Best time to book a flight from Dulles Intl to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Dulles Intl with our price prediction graph.

Cheapflights Insights

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

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

Use this chart to determine the optimal time to book a round-trip flight from Dulles Intl to Ontario. Price data was last updated on April 25, 2025.

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

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

Find hourly flight availability from Dulles Intl 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 April 29, 2025.

Rainfall in Ontario by month

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

Temperature in Ontario by month

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

Reviews of airlines servicing Ontario

Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta from Washington, D.C. to Ontario. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Dulles Intl 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. Dulles Intl?

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

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

Can I find deals for flights from Dulles Intl to Ontario that include hotel bookings?

How can I find direct flights from Dulles Intl to Ontario?

Can I find deals for business class flights from Dulles Intl to Ontario?

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

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Alternative routes for Dulles Intl to Ontario

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Top 4 airlines flying from Dulles Intl to Ontario

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Cheapest flights from Dulles Intl to Ontario
Explore the most affordable flight options available from Dulles Intl to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.