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Southeast Europe

$380+ 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 11/11. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — ATH
Nov 29 — Dec 61
Sat 11/29
Sat 12/6
1 adult, Economy
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Cheap 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 October 30, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$479
(Delta)

One-way from

$380
(Kiwi.com)

Popular in

June

Cheapest in

February

Average price

$750
Provider with most accurate pricing for Los Angeles-Athens Eleftherios V. flight deals.
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Provider most trusted by Cheapflights users for Los Angeles-Athens Eleftherios V. flights.
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From Ontario to Southeast Europe
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One-way flight from Ontario to Southeast Europe
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Highest demand for flights based on searches. 19% potential increase in price ($185 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($27 potential savings vs. average RT price).
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Average for round-trip flights in October 2025
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Find 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 October 30, 2025.

This Delta deal was found by Cheapflights users on 10/30. 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 11/2712:16 pmONT - ATH
2 stops36h 19mDelta
Wed 12/1012:50 pmATH - ONT
2 stops40h 49mDelta
Deal found 10/30$479
This United Airlines deal was found by Cheapflights users on 10/28. 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 12/96:00 amONT - CLJ
2 stops21h 40mUnited Airlines
Wed 1/146:00 amCLJ - ONT
2 stops24h 58mUnited Airlines
Deal found 10/28$495
This Air Canada deal was found by Cheapflights users on 10/30. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/125:05 amONT - ATH
2 stops20h 30mMultiple Airlines
Wed 11/1911:55 amATH - ONT
2 stops34h 42mMultiple Airlines
Deal found 10/30$503
This United Airlines deal was found by Cheapflights users on 10/30. 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 11/117:00 amONT - ATH
2 stops42h 35mUnited Airlines
Tue 12/166:25 amATH - ONT
2 stops26h 24mUnited Airlines
Deal found 10/30$506
This United Airlines deal was found by Cheapflights users on 10/29. 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 11/267:00 amONT - OTP
2 stops21h 00mUnited Airlines
Fri 1/162:50 pmOTP - ONT
2 stops18h 03mUnited Airlines
Deal found 10/29$511
This United Airlines deal was found by Cheapflights users on 10/30. 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 11/309:35 pmONT - OTP
2 stops35h 00mUnited Airlines
Sun 12/145:55 amOTP - ONT
2 stops26h 54mUnited Airlines
Deal found 10/30$523
This Iberia deal was found by Cheapflights users on 10/28. 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.
Fri 11/2810:47 amONT - OTP
2 stops26h 38mMultiple Airlines
Fri 12/58:00 amOTP - ONT
2 stops24h 28mMultiple Airlines
Deal found 10/28$529
This United Airlines deal was found by Cheapflights users on 10/29. 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 11/271:40 pmONT - OTP
2 stops24h 10mUnited Airlines
Wed 1/146:05 amOTP - ONT
2 stops24h 53mUnited Airlines
Deal found 10/29$536
This United Airlines deal was found by Cheapflights users on 10/29. 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 11/261:29 pmONT - ATH
2 stops17h 06mUnited Airlines
Sat 12/66:35 amATH - ONT
2 stops21h 02mUnited Airlines
Deal found 10/29$542
This United Airlines deal was found by Cheapflights users on 10/29. 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 12/61:34 pmONT - ATH
2 stops17h 01mUnited Airlines
Sun 12/1412:50 pmATH - ONT
2 stops19h 59mUnited Airlines
Deal found 10/29$562
This United Airlines deal was found by Cheapflights users on 10/30. 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 11/307:00 amONT - BEG
2 stops20h 50mUnited Airlines
Sun 12/146:15 amBEG - ONT
2 stops25h 34mUnited Airlines
Deal found 10/30$582
This United Airlines deal was found by Cheapflights users on 10/28. 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 11/111:33 pmONT - OTP
2 stops18h 52mUnited Airlines
Tue 11/252:50 pmOTP - ONT
2 stops18h 01mUnited Airlines
Deal found 10/28$603

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 October 30, 2025.
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

OntarioAthens

ONT - ATH

ONTATH

Ontario

Thu 11/27

12:16 pm-10:35 am

2 stops36h 19m

Athens Eleftherios V.

Wed 12/10

12:50 pm-7:39 pm

2 stops40h 49m

$479

OntarioCluj Napoca

ONT - CLJ

ONTCLJ

Ontario

Tue 12/9

6:00 am-1:40 pm

2 stops21h 40m

Cluj Napoca

Wed 1/14

6:00 am-8:58 pm

2 stops24h 58m

$495

OntarioAthens

ONT - ATH

ONTATH

Ontario

Fri 2/13

5:00 am-6:05 pm

2 stops27h 05m

Athens Eleftherios V.

Fri 2/27

6:05 am-12:47 pm

2 stops40h 42m

$500

OntarioAthens

ONT - ATH

ONTATH

Ontario

Wed 11/12

5:05 am-11:35 am

2 stops20h 30m

Athens Eleftherios V.

Wed 11/19

11:55 am-12:37 pm

2 stops34h 42m

$503

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Wed 1/28

10:58 am-8:00 pm

2 stops23h 02m

Bucharest Otopeni Intl

Wed 2/11

8:05 am-10:48 pm

2 stops24h 43m

$504

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Tue 1/27

7:16 am-2:45 pm

2 stops21h 29m

Bucharest Otopeni Intl

Tue 2/10

8:00 am-10:48 pm

2 stops24h 48m

$504

OntarioAthens

ONT - ATH

ONTATH

Ontario

Tue 11/11

6:05 am-10:05 am

2 stops18h 00m

Athens Eleftherios V.

Thu 1/22

6:25 am-5:43 pm

2 stops21h 18m

$506

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Sun 11/30

9:35 pm-6:35 pm

2 stops35h 00m

Bucharest Otopeni Intl

Sun 12/14

5:55 am-10:49 pm

2 stops26h 54m

$523

OntarioBucharest

ONT - OTP

ONTOTP

Ontario

Fri 1/30

7:16 am-3:10 pm

2 stops21h 54m

Bucharest Otopeni Intl

Fri 2/13

8:00 am-10:31 pm

2 stops24h 31m

$529

OntarioAthens

ONT - ATH

ONTATH

Ontario

Thu 2/12

5:00 am-6:05 pm

2 stops27h 05m

Athens Eleftherios V.

Fri 2/27

6:05 am-10:57 pm

2 stops26h 52m

$529

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/30

Showing 1-10 of 60 results
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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 $433). Flying from Ontario to Southeast Europe in June is currently the most expensive (average of $588). 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.

What is the cheapest time of day to fly from ONT to YMH?

Find hourly flight availability from Ontario to Southeast Europe. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 30, 2025.

A simple way to save on the total cost of your ticket is to fly from Ontario to Southeast Europe in the afternoon. If you’re flexible enough to do this you can expect to save up to 8% on your trip compared to booking a flight in the evening.

What is the cheapest day to fly from Ontario to Southeast Europe?

Use this chart to determine the cheapest time to fly round-trip from Ontario to Southeast Europe. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Ontario to Southeast Europe flight should consider departing on Sunday evenings when fares are most often at their lowest. Thursday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

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 October 30, 2025.
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
8,998 reviews

Overall

7.4

Entertainment

7.1

Boarding

7.7

Food

6.6

Crew

8.1

Comfort

7.3

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
8,998 reviews
United Airlines
7.4
Good
8,998 reviews

Overall

7.4

Entertainment

7.1

Boarding

7.7

Food

6.6

Crew

8.1

Comfort

7.3

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 40m. The distance between Ontario and Southeast Europe is about 6133 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Ontario to Southeast Europe one-way?

    The cheapest airlines for a one-way flight from Ontario to Southeast Europe are KLM ($401), United Airlines ($405), and British Airways ($415).

  • 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 - Belgrade Nikola Tesla.

  • 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 $433). Flying from Ontario to Southeast Europe in June is currently the most expensive (average of $588). 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

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Alternative routes for Ontario to Southeast Europe

See prices for flight routes from nearby airports that may be better suited for you.
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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 October 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$635Average$998FlexibilityNo cancel feeOn-time69%

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