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 $255. Other airlines that can offer you cheap pricing are Alaska Airlines, from $297, and American Airlines, from $298. Users have found that Frontier is 43% 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 $136. Hawaiian Airlines flights start at $147 while deals on Alaska Airlines start at $149 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 $130.

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.

$136+ 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 58 days in advance, which can save you up to 82% on flights from Ontario to Washington, D.C. Dulles Intl Airport compared to booking the week you need them. Waiting 58 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 $377. For sooner than that we have options available in the next 3 days from $591.

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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”

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3. Compare prices and book

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Cheapflights Tip: The best prices from Ontario to Washington, D.C. Dulles Intl are usually found in August or February, booked 15 days in advance, depart on a Thursday or Saturday and return on a Thursday

Cheap flight deals from Ontario to Dulles Intl

Round-trip from	$255 (Frontier)
One-way from	$136 (Trip.com)
Popular in	December
Cheapest in	August
Average price	$416

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. 14% potential increase in price ($74 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease ($13 potential savings vs. average RT price).

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Average for round-trip flights in June 2025

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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 June 12, 2025.

Wed 7/97:22 pmONT - IAD

1 stop8h 12mFrontier

Tue 7/157:30 amIAD - ONT

1 stop11h 50mFrontier

Deal found 6/11

$255

Fri 9/57:22 pmONT - IAD

1 stop9h 10mAlaska Airlines

Mon 9/86:09 pmIAD - ONT

1 stop19h 35mAlaska Airlines

Deal found 6/9

$297

Thu 8/711:59 pmONT - IAD

1 stop8h 02mAmerican Airlines

Sun 8/106:27 amIAD - ONT

1 stop8h 26mAmerican Airlines

Deal found 6/11

$298

Thu 7/105:09 pmONT - IAD

2 stops12h 50mDelta

Tue 7/157:45 amIAD - ONT

1 stop7h 29mDelta

Deal found 6/11

$383

Thu 10/96:37 pmONT - IAD

1 stop7h 45mUnited Airlines

Tue 10/212:45 pmIAD - ONT

1 stop8h 39mUnited Airlines

Deal found 6/10

$397

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 June 12, 2025.

Wed 7/97:22 pmONT - IAD

1 stop8h 12mFrontier

Tue 7/157:30 amIAD - ONT

1 stop11h 50mFrontier

Deal found 6/11

$255

Fri 9/57:22 pmONT - IAD

1 stop9h 10mAlaska Airlines

Mon 9/86:09 pmIAD - ONT

1 stop19h 35mAlaska Airlines

Deal found 6/9

$297

Thu 8/711:59 pmONT - IAD

1 stop8h 02mAmerican Airlines

Sun 8/106:27 amIAD - ONT

1 stop8h 26mAmerican Airlines

Deal found 6/11

$298

Thu 7/105:09 pmONT - IAD

2 stops12h 50mDelta

Tue 7/157:45 amIAD - ONT

1 stop7h 29mDelta

Deal found 6/11

$383

Thu 10/96:37 pmONT - IAD

1 stop7h 45mUnited Airlines

Tue 10/212:45 pmIAD - ONT

1 stop8h 39mUnited Airlines

Deal found 6/10

$397

Last-minute flights from Ontario to Dulles Intl
Discover last-minute flight deals from Ontario to Dulles Intl. Data last updated June 12, 2025 and is based on user searches.

Tue 6/175:13 pmONT - IAD

1 stop10h 17mFrontier

Sat 6/217:30 amIAD - ONT

1 stop11h 48mFrontier

Deal found 6/12

$349

Tue 6/1712:00 pmONT - IAD

1 stop8h 59mHawaiian Airlines

Wed 6/186:30 amIAD - ONT

1 stop11h 16mHawaiian Airlines

Deal found 6/9

$807

Tue 6/1712:00 pmONT - IAD

1 stop8h 59mAlaska Airlines

Wed 6/186:30 amIAD - ONT

1 stop20h 43mAlaska Airlines

Deal found 6/10

$877

Sun 6/226:32 pmONT - IAD

1 stop7h 43mUnited Airlines

Fri 7/46:30 amIAD - ONT

1 stop9h 02mUnited Airlines

Deal found 6/10

$627

Sun 6/2212:59 amONT - IAD

1 stop7h 01mAmerican Airlines

Thu 6/266:43 pmIAD - ONT

1 stop7h 19mAmerican Airlines

Deal found 6/11

$662

Mon 6/3010:28 pmONT - IAD

1 stop7h 10mAmerican Airlines

Tue 7/156:27 amIAD - ONT

1 stop8h 29mAmerican Airlines

Deal found 6/10

$331

Wed 7/97:22 pmONT - IAD

1 stop8h 12mFrontier

Tue 7/157:30 amIAD - ONT

1 stop11h 50mFrontier

Deal found 6/11

$255

Thu 7/105:09 pmONT - IAD

2 stops12h 50mDelta

Tue 7/157:45 amIAD - ONT

1 stop7h 29mDelta

Deal found 6/11

$383

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 June 12, 2025.

Wed 8/137:00 amONT - IAD

1 stop20h 34mFrontier

Deal found 6/10

$136

Mon 10/207:25 pmONT - IAD

1 stop9h 08mHawaiian Airlines

Deal found 6/11

$147

Fri 9/267:22 pmONT - IAD

1 stop9h 10mAlaska Airlines

Deal found 6/10

$149

Fri 7/41:15 pmONT - IAD

1 stop7h 28mDelta

Deal found 6/10

$150

Mon 11/1011:59 pmONT - IAD

2 stops9h 53mAmerican Airlines

Deal found 6/11

$157

Mon 10/271:00 pmONT - IAD

1 stop7h 15mUnited Airlines

Deal found 6/10

$199

Sun 10/197:20 amONT - IAD

1 stop7h 30mSouthwest

Deal found 6/10

$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

Wed 7/9

7:22 pm-6:34 am

1 stop8h 12m

Washington, D.C. Dulles Intl

Tue 7/15

7:30 am-4:20 pm

1 stop11h 50m

$255

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Fri 9/5

7:22 pm-7:32 am

1 stop9h 10m

Washington, D.C. Dulles Intl

Mon 9/8

6:09 pm-10:44 am

1 stop19h 35m

$297

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 8/7

11:59 pm-11:01 am

1 stop8h 02m

Washington, D.C. Dulles Intl

Sun 8/10

6:27 am-11:53 am

1 stop8h 26m

$298

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 7/10

5:09 pm-8:59 am

2 stops12h 50m

Washington, D.C. Dulles Intl

Tue 7/15

7:45 am-12:14 pm

1 stop7h 29m

$383

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 10/9

6:37 pm-5:22 am

1 stop7h 45m

Washington, D.C. Dulles Intl

Tue 10/21

2:45 pm-8:24 pm

1 stop8h 39m

$397

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 8/13

7:00 am-6:34 am

1 stop20h 34m

$136

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 10/20

7:25 pm-7:33 am

1 stop9h 08m

$147

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 9/16

11:39 am-12:20 am

1 stop9h 41m

$148

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Fri 7/4

1:15 pm-11:43 pm

1 stop7h 28m

$150

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 10/22

10:33 am-12:02 am

2 stops10h 29m

$154

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/10

Showing 1-10 of 12 results

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 15 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 July is currently the most expensive (average of $349). 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

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

4,287 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

7,946 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

7.9

Good

2,494 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.

United Airlines

7.4

Good

8,790 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 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 $255. Other airlines that can offer you cheap pricing are Alaska Airlines, from $297, and American Airlines, from $298. Users have found that Frontier is 43% 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 $136. Hawaiian Airlines flights start at $147 while deals on Alaska Airlines start at $149 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 July is currently the most expensive (average of $349). 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

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Woodbridge

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Silver Spring

Linthicum Heights

Fredericksburg

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Fairfax

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Reston

National Harbor

Springfield

Manassas

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Top 5 airlines flying from Ontario to Dulles Intl

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$141	Average$268	FlexibilityNo cancel fee	On-time62%
Delta	Cheapest$286	Average$386	FlexibilityNo cancel fee	On-timeN/A
American Airlines	Cheapest$286	Average$404	FlexibilityNo cancel fee	On-time71%
United Airlines	Cheapest$316	Average$475	FlexibilityNo cancel fee	On-time69%
Southwest	Cheapest$326	Average$472	FlexibilityNo cancel fee	On-time63%

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$136+ 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 8/13. 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 15 days in advance, depart on a Thursday or Saturday and return on a Thursday

Cheap flight deals from Ontario to Dulles Intl

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 June 12, 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 June 12, 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.

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 June 9, 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 June 12, 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?

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

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

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

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

Traveling to a place near Ontario?

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Alternative routes for Ontario to Dulles Intl

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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 June 12, 2025.