$112+ Cheap flights from Dulles Intl (IAD) to Ontario (ONT)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/17. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — ONT
Nov 15 — Nov 221
Round-trip
1 adult, Economy
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Find cheap flights from Dulles Intl to Ontario with Cheapflights
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”2. Select your favorite providers
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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Dulles Intl to Ontario
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Cheapest flights from Dulles Intl to OntarioExplore the most affordable flight options available from Dulles Intl to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 16, 2026.
Explore the most affordable flight options available from Dulles Intl to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 16, 2026.
This Mytrip deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/212:06 pm -
2 stops13h 14m
Tue 12/86:00 am -
2 stops26h 11m
Deal found 10/11![Frontier logo]()
$228
This Booking.com deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/110:33 pm -
2 stops26h 47m
Fri 12/411:30 am -
2 stops27h 17m
Deal found 10/11![Frontier logo]()
$247
This Frontier deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1212:31 pm -
1 stop9h 37m
Mon 11/168:03 pm -
1 stop12h 33m
Deal found 10/12![Frontier logo]()
$252
This Mytrip deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/187:48 am -
2 stops19h 03m
Wed 12/211:30 am -
2 stops24h 19m
Deal found 10/11![Frontier logo]()
$258
This Mytrip deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/106:07 pm -
2 stops19h 28m
Tue 11/176:30 am -
2 stops14h 13m
Deal found 10/12![Frontier logo]()
$264
This Frontier deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1312:31 pm -
1 stop9h 37m
Mon 11/168:03 pm -
1 stop12h 33m
Deal found 10/12![Frontier logo]()
$267
This Frontier deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/512:31 pm -
1 stop9h 37m
Wed 12/210:23 am -
1 stop6h 49m
Deal found 10/15![Frontier logo]()
$272
This Mytrip deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/169:06 pm -
2 stops16h 29m
Wed 11/186:30 am -
2 stops14h 13m
Deal found 10/12![Frontier logo]()
$273
This Mytrip deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/117:48 am -
2 stops19h 03m
Sat 11/146:30 am -
2 stops14h 13m
Deal found 10/11![Frontier logo]()
$276
This Frontier deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/612:31 pm -
1 stop9h 37m
Wed 12/210:23 am -
1 stop6h 49m
Deal found 10/15![Frontier logo]()
$277
This Cheapflightsfares deal was found by Cheapflights users on 10/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1312:31 pm -
1 stop9h 37m
Fri 11/202:01 pm -
1 stop12h 09m
Deal found 10/13![Frontier logo]()
$278
This Mytrip deal was found by Cheapflights users on 10/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/176:07 pm -
2 stops19h 28m
Sat 11/212:01 pm -
1 stop12h 09m
Deal found 10/14![Frontier logo]()
$280
Best flights from Dulles Intl to OntarioDiscover carefully curated flight deals from Dulles Intl to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 16, 2026.
Discover carefully curated flight deals from Dulles Intl to Ontario that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 16, 2026.
This United Airlines deal was found by Cheapflights users on 10/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/22:24 pm -
1 stop10h 35m
Tue 12/1511:20 am -
1 stop7h 37m
Deal found 10/14![United Airlines logo]()
$419
This Delta deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/53:04 pm -
1 stop7h 26m
Sat 11/1412:18 pm -
1 stop9h 23m
Deal found 10/15![Delta logo]()
$455
This Alaska Airlines deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/257:05 am -
1 stop10h 58m
Tue 1/54:16 pm -
1 stop21h 11m
Deal found 10/15![Alaska Airlines logo]()
$522
This United Airlines deal was found by Cheapflights users on 10/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/173:30 pm -
1 stop10h 01m
Tue 1/125:00 am -
1 stop7h 46m
Deal found 10/13![United Airlines logo]()
$455
This Delta deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/243:03 pm -
1 stop7h 27m
Wed 12/21:11 pm -
1 stop7h 36m
Deal found 10/15![Delta logo]()
$489
This United Airlines deal was found by Cheapflights users on 10/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/72:38 pm -
1 stop8h 37m
Mon 11/169:25 am -
1 stop9h 31m
Deal found 10/14![United Airlines logo]()
$481
This Delta deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/266:00 am -
1 stop8h 03m
Tue 12/11:11 pm -
1 stop7h 36m
Deal found 10/15![Delta logo]()
$499
This United Airlines deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/281:15 pm -
1 stop8h 32m
Wed 11/111:29 pm -
1 stop6h 46m
Deal found 10/15![United Airlines logo]()
$489
This United Airlines deal was found by Cheapflights users on 10/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/254:10 pm -
1 stop7h 41m
Wed 12/211:20 am -
1 stop7h 37m
Deal found 10/13![United Airlines logo]()
$491
This United Airlines deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/121:05 pm -
1 stop8h 39m
Tue 1/59:45 am -
1 stop8h 10m
Deal found 10/15![United Airlines logo]()
$501
This United Airlines deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/112:05 pm -
1 stop9h 46m
Sun 11/151:35 pm -
1 stop8h 24m
Deal found 10/11![United Airlines logo]()
$506
This United Airlines deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 1/13:30 pm -
1 stop10h 01m
Tue 1/59:45 am -
1 stop8h 10m
Deal found 10/11![United Airlines logo]()
$535
Last-minute flights from Dulles Intl to OntarioDiscover last-minute flight deals from Dulles Intl to Ontario. Data last updated October 16, 2026 and is based on user searches.
Discover last-minute flight deals from Dulles Intl to Ontario. Data last updated October 16, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/512:31 pm -
1 stop9h 37m
Wed 12/210:23 am -
1 stop6h 49m
Deal found 10/15![Frontier logo]()
$272
This Frontier deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/612:31 pm -
1 stop9h 37m
Wed 12/210:23 am -
1 stop6h 49m
Deal found 10/15![Frontier logo]()
$277
This Mytrip deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/106:07 pm -
2 stops19h 28m
Tue 11/176:30 am -
2 stops14h 13m
Deal found 10/12![Frontier logo]()
$264
This Mytrip deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/117:48 am -
2 stops19h 03m
Sat 11/146:30 am -
2 stops14h 13m
Deal found 10/11![Frontier logo]()
$276
This Frontier deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1212:31 pm -
1 stop9h 37m
Mon 11/168:03 pm -
1 stop12h 33m
Deal found 10/12![Frontier logo]()
$252
This Frontier deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1312:31 pm -
1 stop9h 37m
Mon 11/168:03 pm -
1 stop12h 33m
Deal found 10/12![Frontier logo]()
$267
This Cheapflightsfares deal was found by Cheapflights users on 10/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1312:31 pm -
1 stop9h 37m
Fri 11/202:01 pm -
1 stop12h 09m
Deal found 10/13![Frontier logo]()
$278
This Mytrip deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/169:06 pm -
2 stops16h 29m
Wed 11/186:30 am -
2 stops14h 13m
Deal found 10/12![Frontier logo]()
$273
This Mytrip deal was found by Cheapflights users on 10/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/176:07 pm -
2 stops19h 28m
Sat 11/212:01 pm -
1 stop12h 09m
Deal found 10/14![Frontier logo]()
$280
This Mytrip deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/187:48 am -
2 stops19h 03m
Wed 12/211:30 am -
2 stops24h 19m
Deal found 10/11![Frontier logo]()
$258
One-way flights from Dulles Intl to OntarioSearch for one-way flight options from Dulles Intl to Ontario. Find affordable one-way fares based on user searches. Data last updated October 16, 2026.
Search for one-way flight options from Dulles Intl to Ontario. Find affordable one-way fares based on user searches. Data last updated October 16, 2026.
This Mytrip deal was found by Cheapflights users on 10/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/176:07 pm -
2 stops19h 28m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/13![Frontier logo]()
$112
This Mytrip deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/106:07 pm -
2 stops19h 28m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/11![Frontier logo]()
$114
This Booking.com deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/212:06 pm -
2 stops13h 14m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/11![Frontier logo]()
$116
This Mytrip deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/110:33 pm -
2 stops15h 12m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/12![Frontier logo]()
$117
This Kiwi.com deal was found by Cheapflights users on 10/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1512:06 pm -
2 stops25h 39m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/15![Frontier logo]()
$118
This Super.com deal was found by Cheapflights users on 10/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1212:31 pm -
1 stop9h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/13![Frontier logo]()
$124
This Trip.com deal was found by Cheapflights users on 10/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/169:06 pm -
2 stops16h 29m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/12![Frontier logo]()
$128
This Super.com deal was found by Cheapflights users on 10/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/239:56 pm -
1 stop11h 24m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/11![Frontier logo]()
$130
Find flight deals from Dulles Intl to Ontario
Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated October 16, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $228 (Mytrip) |
One-way from | $112 (Mytrip) |
Popular in | April |
Cheapest in | January |
Average price | $804 |
Cheapflights Fare Finder
Customize your flight search to find flights from Dulles Intl to Ontario 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, Cheapflights users made 7,457,451 searches. Data last updated October 16, 2026.
Use the filters below to find and compare flights from Washington, D.C. Dulles Intl Airport to Ontario that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Wed 1/13
7:15 am-12:30 pm
1 stop8h 15m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$176
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Fri 11/6
5:38 pm-10:48 pm
1 stop8h 10m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$176
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Sat 11/7
6:13 am-12:36 pm
1 stop9h 23m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$176
Quickest round-trip
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Tue 11/3
3:04 pm-7:30 pm
1 stop7h 26m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$176
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Tue 4/13
7:00 am-2:47 pm
1 stop10h 47m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$216
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Wed 10/28
7:02 am-1:16 pm
1 stop9h 14m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$227
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Thu 12/10
7:00 am-4:05 pm
1 stop12h 05m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$230
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Tue 4/13
4:10 pm-11:06 pm
1 stop9h 56m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$241
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Tue 1/12
4:15 pm-9:00 pm
1 stop7h 45m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$241
Washington, D.C.Ontario
IAD Washington, D.C. Dulles Intl - ONT Ontario
IADONT
Washington, D.C. Dulles Intl
Thu 1/14
9:21 am-5:35 pm
1 stop11h 14m
Ontario
Wed 12/31
12:00 am-3:00 am
Nonstop0h 00m
$241
Showing 1-10 of 24 resultsSorted by cheapest first
Compare providers for flights from Dulles Intl to Ontario
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to Ontario in October.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C. Dulles Intl Airport-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-Ontario flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-Ontario flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from Dulles Intl to Ontario
Have a flexible travel schedule? Discover the best time to fly to Ontario from Dulles Intl with our price prediction graph.
IAD-ONT
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 Washington, D.C. Dulles Intl Airport to Ontario
How far ahead should I book a flight from Washington, D.C. Dulles Intl Airport to Ontario?
The best time to book flights from Washington, D.C. Dulles Intl Airport to Ontario is 49 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to Ontario?
Currently, January is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to Ontario (average of $345). Flying from Washington, D.C. Dulles Intl Airport to Ontario in April is currently the most expensive (average of $917). 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.
How much does it cost to fly round-trip from Washington, D.C. Dulles Intl Airport to Ontario?
Airfare is below average for this route at the moment.
Washington, D.C. Dulles Intl Airport to Ontario flights typically cost between $365 and $804 in December.The cheapest round-trip price found within the last 5 days was $228 on Frontier (Dec 2-Dec 8).
Reviews of airlines servicing Ontario
Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated October 16, 2026.
Read reviews from past customers who have flown Southwest,Delta, andUnited Airlines from Washington, D.C. Dulles Intl Airport to Ontario. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Entertainment
7.4
Overall
7.9
Food
7.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentWalter,May 2026
LAS - BUR
Entertainment
7.4
Overall
7.9
Food
7.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentWalter,May 2026
LAS - BUR
Entertainment
7.4
Overall
7.9
Food
7.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentWalter,May 2026
LAS - BUR
Entertainment
7.4
Overall
7.9
Food
7.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentWalter,May 2026
LAS - BUR
Entertainment
7.4
Overall
7.9
Food
7.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentWalter,May 2026
LAS - BUR
Entertainment
7.4
Overall
7.9
Food
7.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentWalter,May 2026
LAS - BUR
Related info for your journey
Find useful and relevant information for your journey from Dulles Intl to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Complete your trip to Ontario by adding a car rental and/or hotel reservation to your travel itinerary.
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Find flights from Dulles Intl to Ontario, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Other flights to Ontario
Explore flights to Ontario departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on October 16, 2026.
Dulles Intl and Ontario flights
Browse other Dulles Intl and Ontario flight options. Last updated on October 16, 2026.
Other flights from Dulles Intl
Browse through other flights departing from Dulles Intl. Flights are based on user searches made on Cheapflights and were last updated on October 16, 2026.
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Check out other popular destinations found by fellow travelers in 2026
Top 5 airlines flying from Dulles Intl to Ontario
Discover the top 5 airlines that operate flights from Dulles Intl to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated October 16, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$178 | Average$400 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$269 | Average$437 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$291 | Average$526 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$318 | Average$547 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$340 | Average$518 | FlexibilityNo cancel fee | On-time71% |