C$320 Cheap Flights from Washington, D.C. to Ontario International

Compare Washington, D.C. to Ontario International flight deals

Find the cheapest month or even day of the year to fly to Ontario International

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Flight deals from Washington, D.C. to Ontario International

Looking for a cheap last-minute deal or the best round-trip flight from Washington, D.C. to Ontario International Airport? If you want to travel next month, round-trip fares start from C$320. Find the lowest prices on one-way and round-trip tickets right here.

Ontario.C$160 per passenger.Departing Tue, Sep 1.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from Washington Dulles on Tue, Sep 1, arriving in Ontario International.Price includes taxes and charges.From C$160, select.

Ontario.C$168 per passenger.Departing Tue, Aug 11.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from Washington Dulles on Tue, Aug 11, arriving in Ontario International.Price includes taxes and charges.From C$168, select.

Ontario.C$182 per passenger.Departing Fri, Jul 3.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departing from Baltimore Washington International on Fri, Jul 3, arriving in Ontario International.Price includes taxes and charges.From C$182, select.

Ontario.C$228 per passenger.Departing Sat, Oct 24.One-way flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departing from Washington Dulles on Sat, Oct 24, arriving in Ontario International.Price includes taxes and charges.From C$228, select.

Ontario.C$228 per passenger.Departing Sat, Jun 27.One-way flight with United.Outbound indirect flight with United, departing from Washington Ronald Reagan on Sat, Jun 27, arriving in Ontario International.Price includes taxes and charges.From C$228, select.

Ontario.C$229 per passenger.Departing Mon, Nov 9.One-way flight with Delta.Outbound indirect flight with Delta, departing from Washington Dulles on Mon, Nov 9, arriving in Ontario International.Price includes taxes and charges.From C$229, select.

Ontario.C$271 per passenger.Departing Wed, Dec 2.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departing from Washington Ronald Reagan on Wed, Dec 2, arriving in Ontario International.Price includes taxes and charges.From C$271, select.

Ontario.C$272 per passenger.Departing Wed, Jul 15.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departing from Baltimore Washington International on Wed, Jul 15, arriving in Ontario International.Price includes taxes and charges.From C$272, select.

Ontario.C$308 per passenger.Departing Thu, Jan 21.One-way flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departing from Washington Ronald Reagan on Thu, Jan 21, arriving in Ontario International.Price includes taxes and charges.From C$308, select.

Ontario.C$308 per passenger.Departing Thu, Mar 11.One-way flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departing from Washington Ronald Reagan on Thu, Mar 11, arriving in Ontario International.Price includes taxes and charges.From C$308, select.

Ontario.C$309 per passenger.Departing Wed, Apr 14.One-way flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departing from Washington Dulles on Wed, Apr 14, arriving in Ontario International.Price includes taxes and charges.From C$309, select.

Ontario.C$399 per passenger.Departing Mon, Jun 29.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departing from Baltimore Washington International on Mon, Jun 29, arriving in Ontario International.Price includes taxes and charges.From C$399, select.

Ontario.C$399 per passenger.Departing Mon, Aug 3.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departing from Baltimore Washington International on Mon, Aug 3, arriving in Ontario International.Price includes taxes and charges.From C$399, select.

Find the cheapest month to fly from Washington, D.C. to Ontario International

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Washington, D.C. to Ontario International flights are currently cheapest in September.

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Washington, D.C. to Ontario International: Alternative routes

Compare routes from Washington, D.C. to Ontario below. You may find an airport to fly into that's cheaper, faster, or easier than Ontario International.

Washington, D.C. to Ontario: Flight information

The things to know before you go.

Cheapest flight found	C$160
Cheapest month to fly	September
Average flight time	5 hrs, 20 mins
Most popular airline	Southwest Airlines
Average flights per week	5

Finding cheap flights from Washington, D.C. to Ontario International: Frequently asked questions

How much are round-trip flights from Washington, D.C. to Ontario International?

The best price we found for a round-trip flight from Washington, D.C. to Ontario International is C$320. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.

How long does it take to fly from Washington, D.C. to Ontario International?

5 hours and 20 minutes is the average flight time from Washington, D.C. to Ontario International.

Which airlines fly direct from Washington, D.C. to Ontario International?

Southwest Airlines flies direct from Washington, D.C. to Ontario International.

How many flights are there a week from Washington, D.C. to Ontario International?

There are 5 flights per week flying from Washington, D.C. to Ontario International, as of June 2026.

When is the cheapest time to fly from Washington, D.C. to Ontario International?

The cheapest month to fly from Washington, D.C. to Ontario International is usually July.

Which upcoming date is cheapest to fly from Washington, D.C. to Ontario International Airport on?

After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Washington, D.C. to Ontario International Airport on Saturday, July 4, 2026.

Can I get a direct flight from Washington, D.C. to Ontario International Airport?

Yes – the average flight time is 5 hours and 20 minutes.

How can I find the best flight deal to Ontario International?

We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Ontario International but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

When is the best time to book flights to Ontario?

We crunched all the numbers in our flight calendar, and it looks like the cheapest time to book a flight to Ontario is around 40 days in advance, so don’t leave your flight to the last minute.

Flying from Washington DC to Ontario International Airport (ONT): What you need to know

Kick off your travels at Baltimore Washington International Airport (BWI), the main airport in Washington DC. Search for flights from Washington DC to Ontario International Airport (ONT) that take off from this terminal.
The timezone in Ontario is UTC-8, which is three hours behind Washington DC. Ontario International Airport is located in Ontario.
Arriving two hours before an international flight and one hour ahead of a domestic departure are travel rules worth sticking to. Get to the airport on time to catch your flight from Washington DC to ONT.
July is a busy time to fly out. If you're taking off then or during a major holiday like Thanksgiving, show up even earlier. Aim for at least two hours ahead for domestic flights and as much as four hours for international journeys.

Airports in Washington DC

Ronald Reagan Washington National Airport (DCA)

Located around 6 kilometres from the centre of Washington DC, DCA can be reached in about 10 minutes by car, depending on traffic. The journey by public transport takes roughly 25 minutes.
Catching an early flight from Washington DC to Ontario International Airport? Avoid rushing to the terminal (and sneak in some extra precious sleep) by choosing one of these stays close to Ronald Reagan Washington National Airport:
When it comes to the on-time performance of Ronald Reagan Washington National Airport, 71% of flights complete their journey on time.
DCA is located at 1 Aviation Circle.

Washington Dulles International Airport (IAD)

With public transport, you can travel from central Washington DC to IAD in around 1 hour 10 minutes. The terminal is roughly 40 kilometres away, and making the trip by car takes approximately 45 minutes.
Get your vacation started early with an additional night away from home. Before your Washington DC to ONT flight, kick back in one of these hotels near Washington Dulles International Airport:
77% of flights leaving Washington Dulles International Airport make it to their destination as expected.
IAD is located at 1 Saarinen Circle.

Baltimore Washington International Airport (BWI)

Avoid the hassle of switching planes from Baltimore Washington International Airport (BWI). Direct flights from Washington DC to Ontario International Airport can be booked from here.
Southwest Airlines is one trusted airline that offers direct Washington DC to ONT plane tickets from BWI.
Most passengers choose to fly with Southwest Airlines from BWI to ONT.
Southwest Airlines is the most punctual carrier on this route.
The journey time to BWI from the centre of Washington DC is around 50 minutes by public transport. If you're planning to travel by car, it'll take you roughly 40 minutes to cover the 48 kilometres or so.
Make catching an early Washington DC to Ontario International Airport flight the easiest part of your journey. Book a room at one of these accommodation options close to Baltimore Washington International Airport and get to your check-in counter with plenty of time to spare:
The on-time performance rate of BWI is 77%. To put it simply, that's how often flights that depart this airport arrive at their final stop as planned.

About Ontario International Airport (ONT)

Reserve a hotel near ONT if you're catching a late flight from Washington DC to Ontario International Airport. Check in to one of these options and be in bed sooner:
Lock in the lowest price by reserving your vehicle around three weeks ahead of your Washington DC to Ontario International Airport flight.
The address for ONT is 2900 E. Airport Drive.

Getting from Ontario International Airport (ONT) to central Ontario

Ontario International Airport is around 10 kilometres from the centre of Ontario. It takes around 15 minutes or so to drive to the city.
If you're taking public transport, expect a journey time of about 45 minutes.

How to find the cheapest flights from Washington DC to Ontario International Airport (ONT)

C$160 is the best price for a one-way ticket from Washington DC to Ontario International Airport. Return flights start from C$320. These fares can change based on demand.
Don't leave things to the last minute. You're more likely to walk away with cheap flights from Washington DC to ONT if you book early. Airlines often have some amazing early bird discounts.
Cheap Washington DC to Ontario International Airport tickets are easier to find if your travel dates are flexible. Use the 'Whole month' tool to compare fares throughout the month and then choose the cheapest day.
There's no need to check every day to find out if prices have dropped when you set up a Price Alert. We'll notify you when a better deal is available on plane tickets from Washington DC to ONT.
Hunt down a great price on a flight from Washington DC to Ontario International Airport with the help of the filters. Choose your preferred arrival and departure times, airlines and number of stops. You can also sort your results by 'Fastest,' 'Best' or 'Cheapest.'

The best time to fly from Washington DC to Ontario International Airport (ONT)

It's time to work out when to book your flight from Washington DC to Ontario International Airport (ONT). July is the most popular month to visit Ontario. If you prefer a quieter vibe, think about going in December.
Before locking in your Washington DC to ONT plane ticket, consider what kind of weather works for you. August is the warmest month in Ontario, with temperatures ranging from 16ºC (61ºF) to 36ºC (97ºF).
If you like travelling in cooler conditions, look for a cheap ticket from Washington DC to Ontario International Airport in February when temperatures are between 4ºC (39ºF) and 24ºC (75ºF).

More about Ontario

After booking your flight from Washington DC to Ontario International Airport, find a hotel that's got location and comfort covered. Make one of these options your base for exploring Ontario:
Make the most of your getaway to Ontario by discovering major attractions like Graber Olive House.

Explore more of the United States

San Diego is just one of the many cities in the United States waiting to be explored after you've experienced Ontario. Around 153 kilometres away to the south, top sights here include San Diego Zoo, San Diego Balboa Park and USS Midway Museum.
Bakersfield is another favourite destination in the United States and is around 193 kilometres northwest of Ontario. No journey is complete without experiencing Kern County Museum, Rabobank Arena, Theatre & Convention Centre and Bakersfield Museum of Art.

Plan the rest of your trip from Washington, D.C. to Ontario

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.

C$160 Cheap Flights from Washington, D.C. to Ontario International