Cheap flights from Baltimore Washington International to Ontario International

Compare Baltimore Washington International to Ontario International flight deals

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

Book the best Ontario International fare with no extra fees

Flight deals from Baltimore Washington International to Ontario International

Looking for a cheap last-minute deal or the best return flight from Baltimore Washington International Airport to Ontario International Airport? If you want to travel next month, return fares start from $267. Find the lowest prices on one-way and return tickets right here.

Ontario.$141 per passenger.Departing Wed, 27 May.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Baltimore Washington International on Wed, 27 May, arriving in Ontario International.Price includes taxes and charges.From $141, select.

Ontario.$146 per passenger.Departing Tue, 2 Jun.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Baltimore Washington International on Tue, 2 Jun, arriving in Ontario International.Price includes taxes and charges.From $146, select.

Ontario.$166 per passenger.Departing Thu, 3 Sep.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Baltimore Washington International on Thu, 3 Sep, arriving in Ontario International.Price includes taxes and charges.From $166, select.

Ontario.$166 per passenger.Departing Wed, 29 Jul.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Baltimore Washington International on Wed, 29 Jul, arriving in Ontario International.Price includes taxes and charges.From $166, select.

Ontario.$173 per passenger.Departing Thu, 20 Aug.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from Baltimore Washington International on Thu, 20 Aug, arriving in Ontario International.Price includes taxes and charges.From $173, select.

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

Ontario.$250 per passenger.Departing Tue, 7 Jul.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Baltimore Washington International on Tue, 7 Jul, arriving in Ontario International.Price includes taxes and charges.From $250, select.

Ontario.$250 per passenger.Departing Tue, 2 Jun.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Baltimore Washington International on Tue, 2 Jun, arriving in Ontario International.Price includes taxes and charges.From $250, select.

Ontario.$265 per passenger.Departing Sat, 30 May.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Baltimore Washington International on Sat, 30 May, arriving in Ontario International.Price includes taxes and charges.From $265, select.

Ontario.$346 per passenger.Departing Wed, 4 Nov.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Baltimore Washington International on Wed, 4 Nov, arriving in Ontario International.Price includes taxes and charges.From $346, select.

Ontario.$346 per passenger.Departing Thu, 10 Dec.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Baltimore Washington International on Thu, 10 Dec, arriving in Ontario International.Price includes taxes and charges.From $346, select.

Ontario.$347 per passenger.Departing Mon, 4 Jan.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from Baltimore Washington International on Mon, 4 Jan, arriving in Ontario International.Price includes taxes and charges.From $347, select.

Ontario.$368 per passenger.Departing Mon, 3 Aug.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from Baltimore Washington International on Mon, 3 Aug, arriving in Ontario International.Price includes taxes and charges.From $368, select.

Find the cheapest month to fly from Baltimore Washington International to Ontario International

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

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Jan

Feb

Mar

Apr

Direct flights from Baltimore Washington International to Ontario International

Baltimore Washington International to Ontario International: Alternative routes

Compare routes from Baltimore Washington International 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	$141
Cheapest month to fly	May
Average flight time	5 hrs, 24 mins
Most popular airline	Southwest Airlines
Average flights per week	7

Finding cheap flights from Baltimore Washington International to Ontario International: Frequently asked questions

How much are return flights from Baltimore Washington International to Ontario International?

The best price we found for a return flight from Baltimore Washington International to Ontario International is $267. 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 Baltimore Washington International to Ontario International?

5 hours and 24 minutes is the average flight time from Baltimore Washington International to Ontario International.

Which airlines fly direct from Baltimore Washington International to Ontario International?

Southwest Airlines flies direct from Baltimore Washington International to Ontario International.

How many flights are there a week from Baltimore Washington International to Ontario International?

As of May 2026, there are 7 flights per week flying from Baltimore Washington International to Ontario International.

When is the cheapest time to fly from Baltimore Washington International to Ontario International?

The cheapest month to fly from Baltimore Washington International to Ontario International is usually June.

Which upcoming date is cheapest to fly from Baltimore Washington International Airport to Ontario International Airport on?

After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Baltimore Washington International Airport to Ontario International Airport on Tuesday, 2 June 2026.

Can I get a direct flight from Baltimore Washington International Airport to Ontario International Airport?

Yes – the average flight time is 5 hours and 24 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.

Which is the cheapest airline to fly from Baltimore Washington International Airport to Ontario International with?

Currently, Frontier Airlines and Southwest Airlines offer the cheapest flight tickets to Ontario International.

Flying from Baltimore/Wash International Thurgood Marshall Airport (BWI) to Ontario International Airport (ONT): what you need to know

Ontario's timezone is UTC-7, making Ontario three hours behind Washington DC.
Give yourself enough time to make your BWI to ONT flight. Generally, it's best to arrive at least two hours before international departures and an hour ahead for domestic flights.
Be prepared for longer lines in popular months such as July. Arriving up to four hours ahead of an international flight and two hours for domestic departures is a good idea.
We make it simple to book a flight with a stopover. To see your options for tickets from Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport, deselect 'Direct flights only.' Then, pick a flight offering a stop long enough to explore the city of your choice. Top stopovers between BWI and ONT include:
- Harry Reid Airport (formerly McCarran Airport)
- Phoenix Sky Harbour International Airport
- Denver International Airport

How to find the cheapest flights from Baltimore/Wash International Thurgood Marshall Airport (BWI) to Ontario International Airport (ONT)

Currently, $141 is the cheapest price we've seen for a one-way Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport flight. The best price for a return plane ticket is $267. Keep in mind that fares may change due to demand at the time of booking.
To pick up cheap tickets from BWI to ONT, book early. Airlines usually offer the most competitive fares when flights are first made available.
If you can be flexible with your trip dates, use the 'Whole month' search tool. It'll give you the lowest price across the month when searching for a flight from Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport.
There's no need to check back in every day to see if fares have gone down when you create a Price Alert. We'll notify you the moment there's a new deal on cheap flights from BWI to ONT.
Find the ideal flight for you with the help of the filters. To see the 'Fastest,' 'Best' or 'Cheapest' flights from Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport, use the 'Sort by' function. You can also filter results by departure and arrival times, airline, and number of stops.

Handy information about Baltimore/Wash International Thurgood Marshall Airport (BWI)

77.13% of flights taking off from Baltimore/Wash International Thurgood Marshall Airport make it to their destination on schedule.
Central Washington DC to Baltimore/Wash International Thurgood Marshall Airport is around 48 kilometres. Depending on traffic, it'll take you about 50 minutes to get there if you're driving, catching a cab or ride-sharing.
You can expect a trip time of roughly 1 hour 30 minutes on public transport.
Get your holiday off to a leisurely start by staying near BWI. Whether you're boarding an early flight from Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport or want to avoid feeling rushed, these hotels are the answer:

Arriving at Ontario International Airport (ONT)

Consider booking a hotel close to ONT if you're taking a late Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport flight. Pick one of these accommodation options and avoid the hassle of a long transfer:
Travel at your own speed with an Ontario International Airport rental car. Pick up your wheels from Dollar, Fox - Rent A Car or Thrifty and see more of Ontario and beyond.
For the best deal, reserve your vehicle from Ontario International Airport around three weeks in advance.

Getting from Ontario International Airport (ONT) to central Ontario

You'll find ONT at 2900 E. Airport Drive.
Ontario International Airport to the centre of Ontario has a drive time of about 10 minutes. It's approximately 6 kilometres away.
When travelling by public transport, expect a journey of around 1 hour 30 minutes.

When to fly to Ontario International Airport (ONT)

August is the busiest month for flights from Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport. For smaller crowds, visit Ontario in May.
The warmest month in Ontario is August, with the temperature ranging between 15ºC (59ºF) and 35ºC (95ºF). Lock in your flights from Baltimore/Wash International Thurgood Marshall Airport to Ontario International Airport in this month if this is the kind of weather you like.
Look for cheap tickets from BWI to ONT in January if you want to travel in cooler conditions. Temperatures are at their lowest around then, ranging between 4ºC (39ºF) and 23ºC (73ºF) on average.

Explore more of United States

You've seen Ontario, now it's time to discover other parts of United States. Travel around 56 kilometres west to Los Angeles to tick off its leading sights. From Griffith Observatory to The Broad and La Brea Tar Pits & Museum, there's plenty to keep you busy.
San Diego is another sought-after destination in United States and is around 153 kilometres south of Ontario. No trip is complete without dropping by San Diego Zoo, USS Midway Museum and SeaWorld San Diego.