HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Southeast Europe

$239+ Cheap flights from Ontario (ONT) to Southeast Europe

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 5/10. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — ATH
Mar 14 — Mar 211
Sat 3/14
Sat 3/21
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ontario to Southeast Europe 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

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

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 Ontario to Southeast Europe

Cheapest flights from Ontario to Southeast Europe
Explore the most affordable flight options available from Ontario to Southeast Europe. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 12, 2026.

This United Airlines deal was found by Cheapflights users on 2/11. 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.
Sun 4/125:10 am
ONT
-
CLJ
2 stops26h 15m
United Airlines
Tue 4/211:50 pm
CLJ
-
ONT
2 stops18h 36m
United Airlines
Deal found 2/11$499
This United Airlines deal was found by Cheapflights users on 2/11. 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.
Sun 4/125:10 am
ONT
-
CLJ
2 stops26h 15m
United Airlines
Mon 4/201:50 pm
CLJ
-
ONT
2 stops40h 46m
United Airlines
Deal found 2/11$510
This United Airlines deal was found by Cheapflights users on 2/9. 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 3/115:15 am
ONT
-
OTP
2 stops23h 45m
United Airlines
Tue 3/175:55 am
OTP
-
ONT
2 stops25h 23m
United Airlines
Deal found 2/9$515
This United Airlines deal was found by Cheapflights users on 2/11. 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.
Tue 8/111:00 pm
ONT
-
OTP
2 stops17h 20m
United Airlines
Tue 8/251:50 pm
OTP
-
ONT
2 stops19h 16m
United Airlines
Deal found 2/11$516
This oojo deal was found by Cheapflights users on 2/9. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/131:10 pm
ONT
-
OTP
2 stops26h 10m
British Airways
Thu 8/208:15 am
OTP
-
ONT
2 stops42h 09m
British Airways
Deal found 2/9$524
This oojo deal was found by Cheapflights users on 2/12. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/112:31 pm
ONT
-
DBV
2 stops20h 34m
British Airways
Tue 8/259:00 pm
DBV
-
ONT
2 stops52h 24m
British Airways
Deal found 2/12$532
This oojo deal was found by Cheapflights users on 2/11. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/65:02 pm
ONT
-
OTP
2 stops22h 18m
British Airways
Mon 4/203:40 pm
OTP
-
ONT
2 stops40h 56m
British Airways
Deal found 2/11$537
This oojo deal was found by Cheapflights users on 2/11. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/1111:59 pm
ONT
-
ZAG
2 stops51h 46m
British Airways
Tue 8/258:20 pm
ZAG
-
ONT
2 stops34h 54m
British Airways
Deal found 2/11$542
This United Airlines deal was found by Cheapflights users on 2/11. 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 4/31:43 pm
ONT
-
OTP
2 stops18h 52m
United Airlines
Fri 4/176:05 am
OTP
-
ONT
2 stops26h 40m
United Airlines
Deal found 2/11$554
This Iberia deal was found by Cheapflights users on 2/9. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/3110:56 am
ONT
-
OTP
2 stops18h 29m
Multiple Airlines
Sun 5/108:10 am
OTP
-
ONT
2 stops24h 26m
Multiple Airlines
Deal found 2/9$556
This United Airlines deal was found by Cheapflights users on 2/9. 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 3/206:00 am
ONT
-
OTP
2 stops32h 50m
United Airlines
Mon 5/41:50 pm
OTP
-
ONT
2 stops43h 09m
United Airlines
Deal found 2/9$561
This United Airlines deal was found by Cheapflights users on 2/9. 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 8/121:00 pm
ONT
-
ZAG
2 stops16h 15m
United Airlines
Wed 8/265:55 am
ZAG
-
ONT
2 stops20h 52m
United Airlines
Deal found 2/9$562

Find flight deals from Ontario to Southeast Europe

Keep the following information in mind while searching for Ontario to Southeast Europe flight deals. Data was last updated February 12, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$499
(United Airlines)

One-way from

$239
(FlightHub)

Popular in

June

Cheapest in

February

Average price

$587
Provider with most accurate pricing for Los Angeles-Athens Eleftherios V. flight deals.
Search Deals
Provider most trusted by Cheapflights users for Los Angeles-Athens Eleftherios V. flights.
Search Deals
From Ontario to Southeast Europe
Search Deals
One-way flight from Ontario to Southeast Europe
Search Deals
Highest demand for flights based on searches. 20% potential increase in price ($193 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($31 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Southeast Europe 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 2,558,603 searches. Data last updated February 12, 2026.
Use the filters below to find and compare flights from Ontario to Southeast Europe that are best for you.

Fly from

Ontario

Fly to

Southeast Europe

Route

Depart

Return

Price

OntarioCluj Napoca

ONT - CLJ

ONTCLJ

Ontario

Sun 4/12

5:10 am-5:25 pm

2 stops26h 15m

Cluj Napoca

Tue 4/21

1:50 pm-10:26 pm

2 stops18h 36m

$499

OntarioCluj Napoca

ONT - CLJ

ONTCLJ

Ontario

Sun 4/12

5:10 am-5:25 pm

2 stops26h 15m

Cluj Napoca

Mon 4/20

1:50 pm-8:36 pm

2 stops40h 46m

$510

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Wed 3/11

5:15 am-2:00 pm

2 stops23h 45m

Bucharest Otopeni Intl

Tue 3/17

5:55 am-10:18 pm

2 stops25h 23m

$515

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Tue 8/11

1:00 pm-4:20 pm

2 stops17h 20m

Bucharest Otopeni Intl

Tue 8/25

1:50 pm-11:06 pm

2 stops19h 16m

$516

OntarioDubrovnik

ONT - DBV

ONTDBV

Ontario

Tue 8/11

10:50 am-8:05 pm

2 stops24h 15m

Dubrovnik

Tue 8/25

9:00 pm-4:24 pm

2 stops52h 24m

$532

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Mon 4/6

5:02 pm-1:20 am

2 stops22h 18m

Bucharest Otopeni Intl

Mon 4/20

3:40 pm-10:36 pm

2 stops40h 56m

$537

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Fri 4/3

1:43 pm-6:35 pm

2 stops18h 52m

Bucharest Otopeni Intl

Fri 4/17

6:05 am-10:45 pm

2 stops26h 40m

$554

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Tue 3/31

10:56 am-3:25 pm

2 stops18h 29m

Bucharest Otopeni Intl

Sun 5/10

8:10 am-10:36 pm

2 stops24h 26m

$556

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Fri 3/20

6:00 am-11:50 pm

2 stops32h 50m

Bucharest Otopeni Intl

Mon 5/4

1:50 pm-10:59 pm

2 stops43h 09m

$561

OntarioBelgrade

ONT - BEG

ONTBEG

Ontario

Tue 3/31

6:00 am-11:55 am

2 stops20h 55m

Belgrade Nikola Tesla

Wed 4/15

12:35 pm-11:44 pm

2 stops20h 09m

$563

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/9

Showing 1-10 of 60 results
1
2
3
...
6

Best time to book a flight from Ontario to Southeast Europe

Have a flexible travel schedule? Discover the best time to fly to Southeast Europe from Ontario with our price prediction graph.
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 Ontario to Southeast Europe

What is the cheapest month to book a flight from Ontario to Southeast Europe?

Currently, August is the cheapest month in which you can book a flight from Ontario to Southeast Europe (average of $420). Flying from Ontario to Southeast Europe in June is currently the most expensive (average of $642). 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.

Reviews of airlines servicing Southeast Europe

Get insights into the airlines that provide service to Southeast Europe. 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 Southeast Europe. Reviews last updated February 12, 2026.
Get a feel of what it's like to fly with United Airlines from Ontario to Southeast Europe by reading reviews from past customers. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,276 reviews

Crew

8.1

Comfort

7.3

Entertainment

7.1

Food

6.6

Boarding

7.7

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
United Airlines
7.4
Good
9,276 reviews
United Airlines
7.4
Good
9,276 reviews

Crew

8.1

Comfort

7.3

Entertainment

7.1

Food

6.6

Boarding

7.7

Overall

7.4

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??

Related info for your journey

Find useful and relevant information for your journey from Ontario to Southeast Europe. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Ontario to Southeast Europe?

    Ontario (ONT), located 3.1 mi from the city center, is the airport you fly out of when you book flights from Ontario to Southeast Europe.

  • How long is the flight from Ontario to Southeast Europe?

    Departing from Ontario to Southeast Europe will take you 20h 55m. The distance between Ontario and Southeast Europe is about 6378 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the most popular routes from Ontario to Southeast Europe?

    The most popular flight routes from Ontario to Southeast Europe are Ontario - Athens Eleftherios V., Ontario - Bucharest Otopeni Intl and Ontario - Zagreb Franjo Tuđman.

  • Can I find deals for flights from Ontario to Southeast Europe that include hotel bookings?

    Yes. In addition to deals on Ontario to Southeast Europe flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to Southeast Europe?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to Southeast Europe.

  • Can I find deals for business class flights from Ontario to Southeast Europe?

    Yes. Cheapflights offers flight deals from Ontario to Southeast Europe by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Ontario to Southeast Europe?

    Currently, August is the cheapest month in which you can book a flight from Ontario to Southeast Europe (average of $420). Flying from Ontario to Southeast Europe in June is currently the most expensive (average of $642). 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.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Ontario to Southeast Europe

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to Heathrow flights
San Francisco to Heathrow flights
Los Angeles to Charles de Gaulle flights
San Francisco to Charles de Gaulle flights
Los Angeles to Leonardo da Vinci/Fiumicino flights
Los Angeles to Istanbul flights
San Francisco to Leonardo da Vinci/Fiumicino flights
Los Angeles to Madrid flights
Los Angeles to Gatwick flights
San Francisco to Barcelona-El Prat flights
San Francisco to Istanbul flights
San Francisco to Gatwick flights
Los Angeles to Stansted flights
Los Angeles to Amsterdam flights
Los Angeles to Barcelona-El Prat flights
Los Angeles to Frankfurt flights
San Francisco to Lisbon flights
Los Angeles to London City flights
Los Angeles to Lisbon flights
Los Angeles to Dublin flights
San Francisco to Stansted flights
San Francisco to London City flights
San Francisco to Amsterdam flights
San Francisco to Orly flights
San Francisco to Dublin flights
Los Angeles to Orly flights
San Francisco to Madrid flights
San Francisco to Athens flights
San Francisco to Frankfurt flights
San Diego to Heathrow flights
Los Angeles to Athens flights
San Francisco to Malpensa flights
San Francisco to Zurich flights
Ontario to Heathrow flights
San Francisco to Linate flights
Los Angeles to Zurich flights
Los Angeles to Luton flights
Los Angeles to Copenhagen flights
Ontario to Charles de Gaulle flights
Los Angeles to Malpensa flights
San Francisco to Munich flights
Los Angeles to Frederic Chopin flights
Los Angeles to Sabiha Gokcen flights
Las Vegas to Heathrow flights
Los Angeles to Beauvais-Tille flights
Santa Ana to Charles de Gaulle flights
Los Angeles to Linate flights
Los Angeles to Keflavik Intl flights
Ontario to Leonardo da Vinci/Fiumicino flights
Santa Ana to Leonardo da Vinci/Fiumicino flights

Top airline flying from Ontario to Southeast Europe

Discover the top airline that operate flights from Ontario to Southeast Europe. 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 2,558,603 searches. Data last updated February 12, 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$660Average$955FlexibilityNo cancel feeOn-time69%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.