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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 9/7. 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

Frontier Logo
4:14 pm - 9:17 amONT-IAD
14h 03m1 stop
Frontier Logo
10:17 am - 3:24 pmIAD-ONT
8h 07m1 stop
$220Frontier
Find Deal
Thu, Sep 25 - Sun, Sep 28
Frontier Logo
4:14 pm - 9:17 amONT-IAD
14h 03m1 stop
Frontier Logo
10:17 am - 6:15 pmIAD-ONT
10h 58m1 stop
$238Frontier
Find Deal
Thu, Sep 11 - Sun, Sep 14
Frontier Logo
7:15 pm - 9:17 amONT-IAD
11h 02m1 stop
Frontier Logo
1:02 pm - 3:24 pmIAD-ONT
29h 22m1 stop
$239Frontier
Find Deal
Sun, Sep 21 - Sat, Sep 27
Logo
4:14 pm - 9:17 amONT-IAD
14h 03m1 stop
Logo
7:00 am - 2:12 pmIAD-ONT
10h 12m1 stop
$248
Find Deal
Thu, Sep 18 - Tue, Sep 23
Logo
7:15 pm - 9:17 amONT-IAD
11h 02m1 stop
Logo
7:00 am - 2:12 pmIAD-ONT
10h 12m1 stop
$249
Find Deal
Sun, Sep 7 - Tue, Sep 16
Alaska Airlines Logo
11:39 am - 12:23 amONT-IAD
9h 44m1 stop
Alaska Airlines Logo
7:00 am - 2:12 pmIAD-ONT
10h 12m1 stop
$296Alaska Airlines
Find Deal
Wed, Sep 17 - Wed, Sep 24
Delta Logo
11:48 am - 12:40 amONT-IAD
9h 52m1 stop
Delta Logo
7:35 am - 5:10 pmIAD-ONT
12h 35m1 stop
$297Delta
Find Deal
Tue, Oct 14 - Wed, Oct 15
Delta Logo
10:00 pm - 11:56 amONT-IAD
10h 56m2 stops
Delta Logo
7:35 am - 5:00 pmIAD-ONT
12h 25m1 stop
$302Delta
Find Deal
Tue, Sep 16 - Wed, Sep 24
Southwest Logo
5:55 am - 9:55 pmONT-IAD
13h 00m2 stops
Southwest Logo
9:05 am - 4:55 pmIAD-ONT
10h 50m2 stops
$313Southwest
Find Deal
Tue, Feb 10 - Wed, Feb 18
Alaska Airlines Logo
7:47 pm - 7:33 amONT-IAD
8h 46m1 stop
Alaska Airlines Logo
6:25 am - 12:37 pmIAD-ONT
9h 12m1 stop
$316Alaska Airlines
Find Deal
Mon, Oct 20 - Sat, Oct 25

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
Oct 14
ONT11:48 amOntario
9h 52m
1 stop
IAD12:40 amWashington, D.C. Dulles Intl
Oct 15
IAD7:35 amWashington, D.C. Dulles Intl
12h 35m
1 stop
ONT5:10 pmOntario
$297
Find similar
Delta
Sep 16
ONT10:00 pmOntario
10h 56m
2 stops
IAD11:56 amWashington, D.C. Dulles Intl
Sep 24
IAD7:35 amWashington, D.C. Dulles Intl
12h 25m
1 stop
ONT5:00 pmOntario
$302
Find similar
Delta
Sep 16
ONT11:55 amOntario
8h 22m
1 stop
IAD11:17 pmWashington, D.C. Dulles Intl
Sep 25
IAD6:00 amWashington, D.C. Dulles Intl
7h 42m
1 stop
ONT10:42 amOntario
$307
Find similar

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

Our best United Airlines deals on Ontario to Washington, D.C. Dulles Intl Airport flight tickets
United Airlines
Sep 8
ONT6:50 pmOntario
9h 10m
1 stop
IAD7:00 amWashington, D.C. Dulles Intl
Sep 15
IAD3:00 pmWashington, D.C. Dulles Intl
8h 33m
1 stop
ONT8:33 pmOntario
$433
Find similar
United Airlines
Sep 10
ONT6:38 pmOntario
7h 44m
1 stop
IAD5:22 amWashington, D.C. Dulles Intl
Sep 16
IAD5:10 pmWashington, D.C. Dulles Intl
8h 20m
1 stop
ONT10:30 pmOntario
$512
Find similar
United Airlines
Sep 9
ONT7:00 amOntario
10h 41m
2 stops
IAD8:41 pmWashington, D.C. Dulles Intl
Sep 16
IAD6:35 amWashington, D.C. Dulles Intl
8h 38m
1 stop
ONT12:13 pmOntario
$517
Find similar

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 August 27, 2025.
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

Thu 9/25

4:14 pm-9:17 am

1 stop14h 03m

Washington, D.C. Dulles Intl

Sun 9/28

10:17 am-3:24 pm

1 stop8h 07m

$220

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 9/11

4:14 pm-9:17 am

1 stop14h 03m

Washington, D.C. Dulles Intl

Sun 9/14

10:17 am-6:15 pm

1 stop10h 58m

$238

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sun 9/21

7:15 pm-9:17 am

1 stop11h 02m

Washington, D.C. Dulles Intl

Sat 9/27

1:02 pm-3:24 pm

1 stop29h 22m

$239

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Thu 9/18

4:14 pm-9:17 am

1 stop14h 03m

Washington, D.C. Dulles Intl

Tue 9/23

7:00 am-2:12 pm

1 stop10h 12m

$248

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Sun 9/7

7:15 pm-9:17 am

1 stop11h 02m

Washington, D.C. Dulles Intl

Tue 9/16

7:00 am-2:12 pm

1 stop10h 12m

$249

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Wed 9/17

11:39 am-12:23 am

1 stop9h 44m

Washington, D.C. Dulles Intl

Wed 9/24

7:00 am-2:12 pm

1 stop10h 12m

$296

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 10/14

11:48 am-12:40 am

1 stop9h 52m

Washington, D.C. Dulles Intl

Wed 10/15

7:35 am-5:10 pm

1 stop12h 35m

$297

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 9/16

10:00 pm-11:56 am

2 stops10h 56m

Washington, D.C. Dulles Intl

Wed 9/24

7:35 am-5:00 pm

1 stop12h 25m

$302

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Tue 2/10

5:55 am-9:55 pm

2 stops13h 00m

Washington, D.C. Dulles Intl

Wed 2/18

9:05 am-4:55 pm

2 stops10h 50m

$313

OntarioWashington, D.C.

ONT - IAD

ONTIAD

Ontario

Mon 10/20

7:47 pm-7:33 am

1 stop8h 46m

Washington, D.C. Dulles Intl

Sat 10/25

6:25 am-12:37 pm

1 stop9h 12m

$316

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 $419. 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 $570.

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 $379 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 $523 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 $444 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.

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

As of August 2025, prices for Ontario to Washington, D.C. Dulles Intl Airport flights are approximately 27% cheaper 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

Direct flights

None
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.
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  • 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. 7h 45m 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 $160Free CancellationRating
5.8
3,202 reviews
Search Frontier flights
DeltaPriceFrom $286Free CancellationRating
7.9
7,977 reviews
Search Delta flights
American AirlinesPriceFrom $286Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $298Free CancellationRating
7.4
8,945 reviews
Search United Airlines flights
SouthwestPriceFrom $326Free CancellationRating
8.0
4,241 reviews
Search Southwest 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
Gettysburg
Arlington
National Harbor
Winchester
Woodbridge
Waldorf
Tysons
Laurel
Silver Spring
Colonial Beach
Fredericksburg
Harpers Ferry
Towson
Manassas
Rockville
Gaithersburg
Reston
Fairfax
Glen Burnie

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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