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 $219 on this airline. An additional option worth looking into is Alaska Airlines, starting at $298. Frontier is priced at 52% 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 $77. However, be on the lookout for offers from Hawaiian Airlines and Delta, 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.

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.

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).

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

American Airlines, Delta and Frontier 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 $359. Cheapflights users have found deals in the month of September for as cheap as $120. The most expensive prices can be found in the month of December.

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. 5 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.

$77+ 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 61 days before your planned departure. Booking around this time can save you about 83% on the cost of this flight compared to booking a flight leaving this week. We have found prices from $402 if you need a flight within two weeks. For flights within the next 72 hours, you can find tickets from as low as $597.

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Cheapflights Tip: The best prices from Washington, D.C. Dulles Intl to Ontario are usually found in June or August, booked 10 days in advance, depart on a Thursday or Tuesday and return on a Thursday

Cheap flight deals from Dulles Intl to Ontario

Round-trip from	$219 (Mytrip)
One-way from	$77 (Priceline)
Popular in	March
Cheapest in	June
Average price	$487

From Washington, D.C. Dulles Intl to Ontario

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

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Highest demand for flights based on searches. 6% potential increase in price ($33 potential increase over avg. RT price).

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Cheapest flight prices on average. 4% potential price decrease ($19 potential savings vs. average RT price).

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Average for round-trip flights in July 2025

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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 July 3, 2025.

Tue 7/227:30 amIAD - ONT

1 stop11h 50mFrontier

Sat 7/265:13 pmONT - IAD

1 stop10h 21mFrontier

Deal found 7/3

$219

Tue 7/296:30 amIAD - ONT

1 stop9h 56mAlaska Airlines

Tue 7/296:58 pmONT - IAD

1 stop9h 29mAlaska Airlines

Deal found 7/1

$298

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 July 3, 2025.

Tue 7/227:30 amIAD - ONT

1 stop11h 50mFrontier

Sat 7/265:13 pmONT - IAD

1 stop10h 21mFrontier

Deal found 7/3

$219

Tue 7/296:30 amIAD - ONT

1 stop9h 56mAlaska Airlines

Tue 7/296:58 pmONT - IAD

1 stop9h 29mAlaska Airlines

Deal found 7/1

$298

Last-minute flights from Dulles Intl to Ontario
Discover last-minute flight deals from Dulles Intl to Ontario. Data last updated July 3, 2025 and is based on user searches.

Tue 7/87:30 amIAD - ONT

1 stop11h 50mFrontier

Tue 7/295:15 pmONT - IAD

1 stop10h 19mFrontier

Deal found 7/2

$232

Tue 7/227:30 amIAD - ONT

1 stop11h 50mFrontier

Sat 7/265:13 pmONT - IAD

1 stop10h 21mFrontier

Deal found 7/3

$219

Tue 7/296:30 amIAD - ONT

1 stop9h 56mAlaska Airlines

Tue 7/296:58 pmONT - IAD

1 stop9h 29mAlaska Airlines

Deal found 7/1

$298

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 July 3, 2025.

Sat 8/912:27 pmIAD - ONT

1 stop9h 47mFrontier

Deal found 7/2

$77

Tue 7/296:30 amIAD - ONT

1 stop9h 56mHawaiian Airlines

Deal found 7/1

$149

Thu 7/316:00 amIAD - ONT

1 stop7h 30mDelta

Deal found 7/2

$150

Wed 10/17:00 amIAD - ONT

1 stop10h 12mAlaska Airlines

Deal found 7/2

$156

Mon 8/117:35 amIAD - ONT

2 stops8h 05mSouthwest

Deal found 7/3

$164

Sat 8/211:07 amIAD - ONT

2 stops10h 46mAmerican Airlines

Deal found 7/2

$169

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

Tue 7/22

7:30 am-4:20 pm

1 stop11h 50m

Ontario

Sat 7/26

5:13 pm-6:34 am

1 stop10h 21m

$219

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 7/29

6:30 am-1:26 pm

1 stop9h 56m

Ontario

Thu 7/31

6:58 pm-7:27 am

1 stop9h 29m

$298

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Sun 8/17

7:30 am-12:14 pm

1 stop7h 44m

Ontario

Fri 8/22

1:15 pm-11:32 pm

1 stop7h 17m

$299

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Sat 8/9

12:27 pm-7:14 pm

1 stop9h 47m

$77

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Tue 10/28

7:43 am-3:14 pm

1 stop10h 31m

$147

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 7/31

6:00 am-10:30 am

1 stop7h 30m

$150

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Thu 11/13

7:43 am-3:14 pm

1 stop10h 31m

$156

Washington, D.C.Ontario

IAD - ONT

IADONT

Washington, D.C. Dulles Intl

Mon 8/11

7:35 am-12:40 pm

2 stops8h 05m

$164

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/2

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 10 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.

Reviews of airlines servicing Ontario

Read reviews from past customers who have flown Alaska Airlines, Southwest, and Delta from Washington, D.C. Dulles Intl Airport to Ontario. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

Alaska Airlines

8.0

Very good

10,000 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

10,000 reviews

Alaska Airlines

8.0

Very good

10,000 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

4,266 reviews

Alaska Airlines

8.0

Very good

10,000 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

7,982 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Hawaiian Airlines

7.8

Good

2,545 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

American Airlines

7.2

Good

10,000 reviews

Alaska Airlines

8.0

Very good

10,000 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. 5 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 $219 on this airline. An additional option worth looking into is Alaska Airlines, starting at $298. Frontier is priced at 52% 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 $77. However, be on the lookout for offers from Hawaiian Airlines and Delta, 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 5 airlines flying from Dulles Intl to Ontario

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$198	Average$327	FlexibilityNo cancel fee	On-time62%
American Airlines	Cheapest$286	Average$376	FlexibilityNo cancel fee	On-time71%
Delta	Cheapest$286	Average$390	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$320	Average$509	FlexibilityNo cancel fee	On-time69%
Southwest	Cheapest$326	Average$576	FlexibilityNo cancel fee	On-time63%

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$77+ 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 8/9. 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 June or August, booked 10 days in advance, depart on a Thursday or Tuesday and return on a Thursday

Cheap flight deals from Dulles Intl to Ontario

Round-trip from

One-way from

Popular in

Cheapest in

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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 July 3, 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 July 3, 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.

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 June 27, 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 July 3, 2025.

Reviews of airlines servicing Ontario

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?

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.

Alternative routes for Dulles Intl to Ontario

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Top 5 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 July 3, 2025.