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Cheap flights from Ontario to Washington, D.C. from $99

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to Washington, D.C. departing on 5/4. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Ontario to Washington, D.C.

Cheap round-trip flights

Enter your travel dates to find the best prices.
Alaska Airlines Logo
3:26 pm - 5:50 am
ONT
-
IAD
11h 24m
1 stop
Alaska Airlines Logo
7:10 am - 2:32 pm
IAD
-
ONT
10h 22m
1 stop
$257Alaska Airlines
Wed, Apr 29 - Tue, May 5
Delta Logo
10:20 pm - 4:28 pm
ONT
-
IAD
15h 08m
2 stops
Delta Logo
6:01 am - 11:47 am
IAD
-
ONT
8h 46m
1 stop
$262Delta
Tue, Mar 3 - Tue, Mar 10
Delta Logo
10:20 pm - 1:34 pm
ONT
-
IAD
12h 14m
2 stops
Delta Logo
6:00 am - 5:12 pm
IAD
-
ONT
14h 12m
2 stops
$267Delta
Tue, Mar 3 - Tue, Mar 10
Multiple Airlines Logo
6:15 am - 6:19 pm
ONT
-
IAD
9h 04m
1 stop
Multiple Airlines Logo
7:10 am - 2:32 pm
IAD
-
ONT
10h 22m
1 stop
$285Multiple Airlines
Thu, Apr 30 - Tue, May 5
United Airlines Logo
1:45 pm - 11:19 pm
ONT
-
IAD
6h 34m
1 stop
United Airlines Logo
2:12 pm - 8:50 pm
IAD
-
ONT
9h 38m
1 stop
$288United Airlines
Thu, Feb 26 - Sat, Feb 28
Alaska Airlines Logo
10:39 am - 12:09 am
ONT
-
IAD
10h 30m
1 stop
Alaska Airlines Logo
7:10 am - 2:30 pm
IAD
-
ONT
10h 20m
1 stop
$297Alaska Airlines
Sat, May 2 - Wed, May 6
Delta Logo
1:15 pm - 12:21 am
ONT
-
IAD
8h 06m
1 stop
Delta Logo
7:00 am - 4:28 pm
IAD
-
ONT
12h 28m
2 stops
$302Delta
Tue, Mar 3 - Tue, Mar 10
Delta Logo
10:20 pm - 1:34 pm
ONT
-
IAD
12h 14m
2 stops
Delta Logo
2:15 pm - 11:51 pm
IAD
-
ONT
12h 36m
2 stops
$307Delta
Tue, Mar 3 - Tue, Mar 10
Delta Logo
1:10 pm - 11:46 pm
ONT
-
IAD
7h 36m
1 stop
Delta Logo
7:30 am - 1:54 pm
IAD
-
ONT
9h 24m
1 stop
$308Delta
Thu, Feb 26 - Wed, Mar 4
American Airlines Logo
9:53 am - 10:53 pm
ONT
-
IAD
10h 00m
2 stops
American Airlines Logo
5:52 pm - 11:59 pm
IAD
-
ONT
9h 07m
1 stop
$313American Airlines
Tue, Mar 3 - Thu, Mar 12

Delta flights from Ontario to Washington, D.C. Dulles Intl Airport

Our best Delta deals on Ontario to Washington, D.C. Dulles Intl Airport flight tickets
Delta
Mar 3
ONT10:20 pmOntario
15h 08m
2 stops
IAD4:28 pmWashington, D.C. Dulles Intl
Mar 10
IAD6:01 amWashington, D.C. Dulles Intl
8h 46m
1 stop
ONT11:47 amOntario
$262
Delta
Mar 3
ONT10:20 pmOntario
12h 14m
2 stops
IAD1:34 pmWashington, D.C. Dulles Intl
Mar 10
IAD6:00 amWashington, D.C. Dulles Intl
14h 12m
2 stops
ONT5:12 pmOntario
$267
Delta
Mar 3
ONT1:15 pmOntario
8h 06m
1 stop
IAD12:21 amWashington, D.C. Dulles Intl
Mar 10
IAD7:00 amWashington, D.C. Dulles Intl
12h 28m
2 stops
ONT4:28 pmOntario
$302

Frontier flights from Ontario to Washington, D.C. Dulles Intl Airport

Our best Frontier deals on Ontario to Washington, D.C. Dulles Intl Airport flight tickets
Frontier
Feb 21
ONT8:09 pmOntario
33h 00m
2 stops
IAD8:09 amWashington, D.C. Dulles Intl
Mar 1
IAD7:14 pmWashington, D.C. Dulles Intl
22h 16m
1 stop
ONT2:30 pmOntario
$315
Frontier
Mar 5
ONT2:08 pmOntario
38h 16m
2 stops
IAD7:24 amWashington, D.C. Dulles Intl
Mar 8
IAD6:25 amWashington, D.C. Dulles Intl
20h 34m
2 stops
ONT11:59 pmOntario
$368
Frontier
Feb 12
ONT2:06 pmOntario
16h 19m
1 stop
IAD9:25 amWashington, D.C. Dulles Intl
Feb 28
IAD10:29 amWashington, D.C. Dulles Intl
11h 45m
2 stops
ONT7:14 pmOntario
$472

momondo Fare Finder

 
Customize your flight search to find flights from Ontario to Washington, D.C. Dulles Intl Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated February 4, 2026.
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 4/29

3:26 pm-5:50 am

1 stop11h 24m

Washington, D.C. Dulles Intl

Tue 5/5

7:10 am-2:32 pm

1 stop10h 22m

$257

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 3/3

10:20 pm-4:28 pm

2 stops15h 08m

Washington, D.C. Dulles Intl

Tue 3/10

6:01 am-11:47 am

1 stop8h 46m

$262

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 3/3

10:20 pm-1:34 pm

2 stops12h 14m

Washington, D.C. Dulles Intl

Tue 3/10

6:00 am-5:12 pm

2 stops14h 12m

$267

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 4/30

6:15 am-6:19 pm

1 stop9h 04m

Washington, D.C. Dulles Intl

Tue 5/5

7:10 am-2:32 pm

1 stop10h 22m

$285

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 2/26

1:45 pm-11:19 pm

1 stop6h 34m

Washington, D.C. Dulles Intl

Sat 2/28

2:12 pm-8:50 pm

1 stop9h 38m

$288

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sat 5/2

10:39 am-12:09 am

1 stop10h 30m

Washington, D.C. Dulles Intl

Wed 5/6

7:10 am-2:30 pm

1 stop10h 20m

$297

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 3/3

1:15 pm-12:21 am

1 stop8h 06m

Washington, D.C. Dulles Intl

Tue 3/10

7:00 am-4:28 pm

2 stops12h 28m

$302

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 3/3

10:20 pm-1:34 pm

2 stops12h 14m

Washington, D.C. Dulles Intl

Tue 3/10

2:15 pm-11:51 pm

2 stops12h 36m

$307

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 2/26

1:10 pm-11:46 pm

1 stop7h 36m

Washington, D.C. Dulles Intl

Wed 3/4

7:30 am-1:54 pm

1 stop9h 24m

$308

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 3/3

9:53 am-10:53 pm

2 stops10h 00m

Washington, D.C. Dulles Intl

Thu 3/12

5:52 pm-11:59 pm

1 stop9h 07m

$313

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Washington, D.C. from

How to get the cheapest flight ticket from Ontario to Washington, D.C. Dulles Intl Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

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

In general, July is the cheapest month to fly from Ontario to Washington, D.C. Dulles Intl Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $307. If you aren’t able to travel to Washington, D.C. Dulles Intl Airport during the month of July, then flying in August is also cheap. Prices for this month can be found on momondo for an average of $326.

What is the cheapest day to depart on your flight to Washington, D.C. Dulles Intl Airport?

Our data shows that Thursday is the least expensive day to fly to Washington, D.C. Dulles Intl Airport. Tickets to fly out on this day can be as low as $421. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Ontario to Washington, D.C. Dulles Intl Airport for around $552.

What is the cheapest time of day to depart on your flight to Washington, D.C. Dulles Intl Airport?

Flying to Washington, D.C. Dulles Intl Airport from Ontario in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $384 when looking at flights departing in the afternoon. If you have a flexible travel schedule, then try to avoid flying at noon when prices are $564 on average. Flights to Washington, D.C. Dulles Intl Airport from Ontario at noon are generally more expensive because this time of day is more convenient for travelers’ schedules.

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

You are more likely to see cheaper flights to Washington, D.C. Dulles Intl Airport from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. Dulles Intl Airport for around $478 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. Dulles Intl Airport from Ontario for as low as $297 on momondo.

Can stopping save me money on Ontario to Washington, D.C. Dulles Intl Airport flights?

You could potentially save up to 4% on your flight if you consider stops on a Ontario to Washington, D.C. Dulles Intl Airport flight.

How have Ontario to Washington, D.C. Dulles Intl Airport flight prices changed over time?

As of February 2026, prices for Ontario to Washington, D.C. Dulles Intl Airport flights are approximately 84% more expensive when compared to flights at the same time last year.

When to book flights from Ontario to Washington, D.C. Dulles Intl Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to Washington, D.C. Dulles Intl Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ontario to Washington, D.C. Dulles Intl Airport (ONT to IAD) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to Washington, D.C. Dulles Intl Airport

Fastest flight time

6h 20m

Direct flights

None
The fastest flight from Ontario to Washington, D.C. Dulles Intl Airport takes 6h 20m
There are no direct flights from Ontario to Washington, D.C. Dulles Intl Airport. There are no popular flight routes from Ontario to Washington, D.C. Dulles Intl Airport.
Search flight deals

  • How far is Ontario to Washington, D.C. Dulles Intl by plane?

    The distance between Ontario and Washington, D.C. Dulles Intl is about 2238.2 mi. 6h 20m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Ontario Airport to Washington, D.C. Dulles Intl Airport?

    Prices for flights from Ontario Airport to Washington, D.C. Dulles Intl Airport are refreshed on a daily basis.

  • How many operators does momondo search for flights from Ontario Airport to Washington, D.C. Dulles Intl Airport?

  • How old do you have to be to fly from Ontario Airport to Washington, D.C. Dulles Intl Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to Washington, D.C. Dulles Intl Airport.

  • What documentation or ID do you need to fly to Washington, D.C. Dulles Intl Airport?

    The necessary travel and health documents for your Washington, D.C. Dulles Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Ontario to Washington, D.C. Dulles Intl Airport?

Best airlines flying from Ontario to Washington, D.C. Dulles Intl Airport

Compare and see reviews for airlines that fly from Ontario to Washington, D.C. Dulles Intl Airport with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $187Free CancellationRating
5.7
3,051 reviews
Search Frontier flights
American AirlinesPriceFrom $278Free CancellationRating
7.2
11,216 reviews
Search American Airlines flights
United AirlinesPriceFrom $298Free CancellationRating
7.4
9,236 reviews
Search United Airlines flights
SouthwestPriceFrom $318Free CancellationRating
8.0
4,272 reviews
Search Southwest flights
DeltaPriceFrom $318Free CancellationRating
7.9
8,138 reviews
Search Delta flights

Traveling to a place near Washington, D.C.?

Book flights to Washington, D.C. if you plan to visit one of these locations
Alexandria
National Harbor
Gettysburg
Arlington
Winchester
Waldorf
Woodbridge
Tysons
Laurel
Colonial Beach
Silver Spring
Towson
Fredericksburg
Gaithersburg
Rockville
Manassas
Springfield
Sterling
Fairfax
Linthicum Heights

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to Washington, D.C.?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Ontario to Washington, D.C.. momondo saves you time and could save you money on your trip.

Can I find flights from Ontario to Washington, D.C. with flexible booking policies on momondo?

Yes. All flights to Washington, D.C. from Ontario on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Ontario to Washington, D.C.?

momondo helps you find the best flight between Ontario and Washington, D.C. by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

I’m not ready to book a flight from Ontario to Washington, D.C. right now. Can momondo alert me if prices change?

Yes. momondo can track prices for Ontario to Washington, D.C. flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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