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

Cheapflights users have booked flights from Ontario to Washington, D.C. Dulles Intl Airport round-trip from $188. Other airlines that can offer you cheap pricing are Alaska Airlines, from $292, and Delta, from $327. Users have found that Frontier is 58% cheaper than the other options available to this destination.

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

To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $75. Hawaiian Airlines flights start at $141 while deals on Alaska Airlines start at $146 one-way.

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

When booking a flight from Ontario to Washington, D.C. Dulles Intl Airport, you may want to consider flying on American Airlines, Delta or Frontier as they are the most popular for this route.

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

Flying to your destination on a Sunday can be more expensive, but this shouldn’t discourage you from finding affordable options to get to Washington, D.C. Dulles Intl Airport. Check prices with Cheapflights to find a great deal for your trip.

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

Flights from Ontario to Washington, D.C. Dulles Intl Airport lean towards being more expensive in December. Prices are generally better when you fly from Ontario to Washington, D.C. Dulles Intl Airport in August, with the cheapest ticket starting at $131.

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

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

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

Most people fly from Ontario (ONT) if they book a flight from Ontario to Washington, D.C. Dulles Intl. On average, Ontario has 0 outbound flights to Washington, D.C. Dulles Intl per day from 5 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

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

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

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

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

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

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

$75+ Flights from Ontario to Washington, D.C. Dulles Intl Airport

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

When searching for a good deal, it’s best to be prepared for potential fluctuations in price. We recommend booking at least 53 days in advance, which can save you up to 75% on flights from Ontario to Washington, D.C. Dulles Intl Airport compared to booking the week you need them. Waiting 53 days out may not be for everyone, so we have options available for flights within the next two weeks, with the lowest price starting at $392. For sooner than that we have options available in the next 3 days from $577.

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Find cheap flights from Ontario to Dulles Intl 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 Ontario to Washington, D.C. Dulles Intl are usually found in August or February, booked 19 days in advance, depart on a Thursday or Saturday and return on a Thursday

Cheap flight deals from Ontario to Dulles Intl

Most accurate provider	FlightHub 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$188 (Frontier)
One-way from	$75 (Trip.com)
Popular in	December
Cheapest in	August
Average price	$429

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

Search Deals

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

Search Deals

From Ontario to Washington, D.C. Dulles Intl

Search Deals

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

Search Deals

Highest demand for flights based on searches. 13% potential increase in price ($71 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease ($12 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in April 2025

Search Deals

Find flight deals from Ontario to Dulles Intl

Cheapest flights from Ontario to Dulles Intl
Explore the most affordable flight options available from Ontario to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 25, 2025.

Sat 5/315:15 pmONT - IAD

1 stop9h 40mFrontier

Mon 6/27:30 amIAD - ONT

1 stop7h 50mFrontier

Deal found 4/24

$188

Thu 10/234:05 pmONT - IAD

1 stop10h 50mAlaska Airlines

Thu 10/307:00 amIAD - ONT

1 stop11h 12mAlaska Airlines

Deal found 4/25

$292

Sun 5/1810:15 pmONT - IAD

1 stop29h 16mMultiple Airlines

Tue 5/279:00 amIAD - ONT

1 stop9h 50mMultiple Airlines

Deal found 4/25

$306

Tue 5/272:55 pmONT - IAD

1 stop11h 57mDelta

Wed 6/46:00 amIAD - ONT

1 stop8h 08mDelta

Deal found 4/25

$327

Wed 5/286:15 amONT - IAD

2 stops10h 17mAmerican Airlines

Sun 6/16:17 amIAD - ONT

1 stop8h 33mAmerican Airlines

Deal found 4/25

$367

Wed 7/91:19 pmONT - IAD

1 stop8h 26mUnited Airlines

Sun 7/136:32 amIAD - ONT

1 stop8h 42mUnited Airlines

Deal found 4/25

$376

Thu 10/27:17 pmONT - IAD

1 stop9h 15mHawaiian Airlines

Mon 10/67:00 amIAD - ONT

1 stop11h 12mHawaiian Airlines

Deal found 4/25

$396

Wed 7/95:30 amONT - IAD

1 stop8h 20mSouthwest

Sun 7/137:55 pmIAD - ONT

2 stops15h 10mSouthwest

Deal found 4/23

$440

Best flights from Ontario to Dulles Intl
Discover carefully curated flight deals from Ontario to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 25, 2025.

Sat 5/315:15 pmONT - IAD

1 stop9h 40mFrontier

Mon 6/27:30 amIAD - ONT

1 stop7h 50mFrontier

Deal found 4/24

$188

Wed 5/287:20 pmONT - IAD

1 stop9h 16mAlaska Airlines

Tue 6/39:00 amIAD - ONT

1 stop9h 50mAlaska Airlines

Deal found 4/25

$292

Sun 5/1810:15 pmONT - IAD

1 stop29h 16mMultiple Airlines

Tue 5/279:00 amIAD - ONT

1 stop9h 50mMultiple Airlines

Deal found 4/25

$306

Tue 5/272:55 pmONT - IAD

1 stop11h 57mDelta

Tue 6/103:31 pmIAD - ONT

1 stop7h 23mDelta

Deal found 4/24

$327

Wed 5/286:15 amONT - IAD

2 stops10h 17mAmerican Airlines

Sun 6/16:17 amIAD - ONT

1 stop8h 33mAmerican Airlines

Deal found 4/25

$367

Fri 6/61:33 pmONT - IAD

1 stop8h 01mUnited Airlines

Mon 6/96:30 amIAD - ONT

1 stop8h 44mUnited Airlines

Deal found 4/24

$427

Wed 7/95:30 amONT - IAD

1 stop8h 20mSouthwest

Sun 7/137:55 pmIAD - ONT

2 stops15h 10mSouthwest

Deal found 4/23

$440

Tue 7/86:58 pmONT - IAD

1 stop9h 29mHawaiian Airlines

Sun 7/136:30 amIAD - ONT

1 stop9h 56mHawaiian Airlines

Deal found 4/23

$487

Last-minute flights from Ontario to Dulles Intl
Discover last-minute flight deals from Ontario to Dulles Intl. Data last updated April 25, 2025 and is based on user searches.

Wed 4/3012:50 pmONT - IAD

1 stop6h 52mAmerican Airlines

Sat 5/35:13 pmIAD - ONT

1 stop7h 45mAmerican Airlines

Deal found 4/24

$689

Sat 5/36:00 amONT - IAD

1 stop11h 43mAlaska Airlines

Tue 5/136:30 amIAD - ONT

1 stop12h 02mAlaska Airlines

Deal found 4/25

$529

Sat 5/35:30 pmONT - IAD

1 stop9h 50mDelta

Mon 5/125:50 pmIAD - ONT

1 stop7h 39mDelta

Deal found 4/25

$589

Sat 5/311:46 amONT - IAD

1 stop9h 12mHawaiian Airlines

Sun 5/46:30 amIAD - ONT

1 stop12h 02mHawaiian Airlines

Deal found 4/25

$701

Sun 5/42:28 pmONT - IAD

1 stop13h 03mFrontier

Tue 5/67:45 amIAD - ONT

1 stop7h 23mFrontier

Deal found 4/24

$188

Sun 5/49:30 amONT - IAD

2 stops12h 35mSouthwest

Tue 5/132:50 pmIAD - ONT

2 stops10h 40mSouthwest

Deal found 4/24

$672

Sun 5/46:48 pmONT - IAD

1 stop9h 31mUnited Airlines

Tue 5/134:00 pmIAD - ONT

1 stop9h 00mUnited Airlines

Deal found 4/24

$752

Fri 5/96:24 pmONT - IAD

1 stop10h 19mHawaiian Airlines

Sun 5/116:30 amIAD - ONT

1 stop12h 02mHawaiian Airlines

Deal found 4/24

$548

Sun 5/1810:15 pmONT - IAD

1 stop29h 16mMultiple Airlines

Tue 5/279:00 amIAD - ONT

1 stop9h 50mMultiple Airlines

Deal found 4/25

$306

Thu 5/229:00 amONT - IAD

2 stops10h 40mSouthwest

Thu 5/292:10 pmIAD - ONT

1 stop9h 15mSouthwest

Deal found 4/24

$467

Sun 5/251:36 pmONT - IAD

1 stop8h 09mUnited Airlines

Mon 6/26:30 amIAD - ONT

1 stop8h 44mUnited Airlines

Deal found 4/25

$427

Tue 5/272:55 pmONT - IAD

1 stop11h 57mDelta

Wed 6/46:00 amIAD - ONT

1 stop8h 08mDelta

Deal found 4/25

$327

One-way flights from Ontario to Dulles Intl
Search for one-way flight options from Ontario to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated April 25, 2025.

Wed 5/71:08 pmONT - IAD

1 stop14h 23mFrontier

Deal found 4/24

$75

Tue 7/156:58 pmONT - IAD

1 stop9h 29mHawaiian Airlines

Deal found 4/23

$141

Tue 6/107:20 pmONT - IAD

1 stop9h 16mAlaska Airlines

Deal found 4/24

$146

Mon 6/236:32 pmONT - IAD

1 stop7h 43mUnited Airlines

Deal found 4/25

$164

Tue 7/155:53 pmONT - IAD

2 stops14h 29mDelta

Deal found 4/25

$169

Thu 7/37:02 pmONT - IAD

2 stops10h 36mAmerican Airlines

Deal found 4/25

$180

Wed 7/29:40 amONT - IAD

2 stops10h 05mSouthwest

Deal found 4/24

$219

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 5/31

5:15 pm-5:55 am

1 stop9h 40m

Washington, D.C. Dulles Intl

Mon 6/2

7:30 am-12:20 pm

1 stop7h 50m

$188

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 5/28

7:20 pm-7:36 am

1 stop9h 16m

Washington, D.C. Dulles Intl

Tue 6/3

9:00 am-3:50 pm

1 stop9h 50m

$292

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sun 5/18

10:15 pm-6:31 am

1 stop29h 16m

Washington, D.C. Dulles Intl

Tue 5/27

9:00 am-3:50 pm

1 stop9h 50m

$306

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 5/27

2:55 pm-5:52 am

1 stop11h 57m

Washington, D.C. Dulles Intl

Tue 6/10

3:31 pm-10:25 pm

1 stop9h 54m

$327

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 5/28

6:15 am-7:32 pm

2 stops10h 17m

Washington, D.C. Dulles Intl

Sun 6/1

6:17 am-11:50 am

1 stop8h 33m

$367

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 7/9

1:19 pm-12:45 am

1 stop8h 26m

Washington, D.C. Dulles Intl

Sun 7/13

6:32 am-12:14 pm

1 stop8h 42m

$376

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 10/2

7:17 pm-7:32 am

1 stop9h 15m

Washington, D.C. Dulles Intl

Mon 10/6

7:00 am-3:12 pm

1 stop11h 12m

$396

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 7/9

5:30 am-4:50 pm

1 stop8h 20m

Washington, D.C. Dulles Intl

Sun 7/13

7:55 pm-8:05 am

2 stops15h 10m

$440

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 5/14

1:08 pm-6:31 am

1 stop14h 23m

$75

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 7/15

6:58 pm-7:27 am

1 stop9h 29m

$141

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/24

Showing 1-10 of 15 results

Compare providers for flights from Ontario to Dulles Intl

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to Dulles Intl 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 Accuracy1 star	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 Ontario-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Ontario-Washington, D.C. Dulles Intl Airport 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 Ontario-Washington, D.C. Dulles Intl Airport 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 Ontario to Dulles Intl

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

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

The price you pay for your flight from Ontario to Washington, D.C. Dulles Intl Airport may vary depending on when you book. For the best chance of a lower fare, look to book 19 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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

Currently, August is the cheapest month in which you can book a flight from Ontario to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Ontario to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $383). 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 ONT to IAD?

A simple way to save on the total cost of your ticket is to fly from Ontario to Washington, D.C. Dulles Intl Airport in the afternoon. If you’re flexible enough to do this you can expect to save up to 16% on your trip compared to booking a flight in the morning.

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

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

Rainfall in Dulles Intl by month

In terms of precipitation, rainfall in Washington, D.C. Dulles Intl Airport ranges from 2.6 - 4.0 inches per month. May is typically the wettest month, when rainfall can reach 4.0 in. February is typically the driest time to visit Washington, D.C. Dulles Intl Airport when rainfall is around 2.6 in.

Temperature in Dulles Intl by month

If weather is an important factor for your trip to Washington, D.C. Dulles Intl Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 35.6 F).

Reviews of airlines servicing Dulles Intl

Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta from Ontario to Washington, D.C.. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Alaska Airlines

8.0

Very good

9,927 reviews

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Alaska Airlines

8.0

Very good

9,927 reviews

Alaska Airlines

8.0

Very good

9,927 reviews

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Southwest

8.0

Very good

4,289 reviews

Alaska Airlines

8.0

Very good

9,927 reviews

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Delta

8.0

Very good

7,920 reviews

Alaska Airlines

8.0

Very good

9,927 reviews

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Hawaiian Airlines

7.9

Good

2,393 reviews

Alaska Airlines

8.0

Very good

9,927 reviews

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

United Airlines

7.4

Good

8,685 reviews

Alaska Airlines

8.0

Very good

9,927 reviews

Reviews

1 / 20

10.0

Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Related info for your journey

What airport do you fly from for flights from Ontario to Washington, D.C. Dulles Intl?
Most people fly from Ontario (ONT) if they book a flight from Ontario to Washington, D.C. Dulles Intl. On average, Ontario has 0 outbound flights to Washington, D.C. Dulles Intl per day from 5 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.
What are the cheapest airlines flying from Ontario to Washington, D.C. Dulles Intl Airport round-trip?
Cheapflights users have booked flights from Ontario to Washington, D.C. Dulles Intl Airport round-trip from $188. Other airlines that can offer you cheap pricing are Alaska Airlines, from $292, and Delta, from $327. Users have found that Frontier is 58% cheaper than the other options available to this destination.
What are the cheapest airlines to fly from Ontario to Washington, D.C. Dulles Intl Airport one-way?
To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $75. Hawaiian Airlines flights start at $141 while deals on Alaska Airlines start at $146 one-way.
Can I find deals for flights from Ontario to Dulles Intl that include hotel bookings?
Yes. In addition to deals on Ontario to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Ontario to Dulles Intl?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to Dulles Intl.
Can I find deals for business class flights from Ontario to Dulles Intl?
Yes. Cheapflights offers flight deals from Ontario to Dulles Intl 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 Ontario to Washington, D.C. Dulles Intl Airport?
Currently, August is the cheapest month in which you can book a flight from Ontario to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Ontario to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $383). 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

Arlington

Alexandria

Woodbridge

Fairfax

Tysons

Springfield

Rockville

Fredericksburg

Gaithersburg

Silver Spring

Linthicum Heights

Falls Church

Laurel

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Herndon

Sterling

Bowie

Towson

National Harbor

Oxon Hill

Browse thousands of different options on Cheapflights for your next trip

Top 5 airlines flying from Ontario to Dulles Intl

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$153	Average$335	FlexibilityNo cancel fee	On-time62%
Delta	Cheapest$286	Average$386	FlexibilityNo cancel fee	On-timeN/A
American Airlines	Cheapest$286	Average$433	FlexibilityNo cancel fee	On-time71%
United Airlines	Cheapest$312	Average$491	FlexibilityNo cancel fee	On-time69%
Southwest	Cheapest$396	Average$507	FlexibilityNo cancel fee	On-time63%

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$75+ Cheap flights from Ontario (ONT) to Dulles Intl (IAD)

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 Ontario to Dulles Intl 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 Ontario to Washington, D.C. Dulles Intl are usually found in August or February, booked 19 days in advance, depart on a Thursday or Saturday and return on a Thursday

Cheap flight deals from Ontario to Dulles Intl

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Find flight deals from Ontario to Dulles Intl

Cheapest flights from Ontario to Dulles IntlExplore the most affordable flight options available from Ontario to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 25, 2025.

Explore the most affordable flight options available from Ontario to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 25, 2025.

Cheapflights Fare Finder

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

Compare providers for flights from Ontario to Dulles Intl

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 Ontario to Dulles Intl in April.

Best time to book a flight from Ontario to Dulles Intl

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

Cheapflights Insights

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

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

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Dulles Intl. Price data was last updated on April 18, 2025.

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

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

Find hourly flight availability from Ontario to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 25, 2025.

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

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

Rainfall in Dulles Intl by month

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

Temperature in Dulles Intl by month

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

Reviews of airlines servicing Dulles Intl

Read reviews from past customers who have flown Alaska Airlines, Southwest and Delta from Ontario to Washington, D.C.. You can also see how each airline compares 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 Ontario to Dulles Intl. 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 from for flights from Ontario to Washington, D.C. Dulles Intl?

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

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

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

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Top 5 airlines flying from Ontario to Dulles Intl

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Cheapest flights from Ontario to Dulles Intl
Explore the most affordable flight options available from Ontario to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 25, 2025.