$555 Find Cheap Flights from Greece to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Ontario departing on 3/26. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to Ontario

 
These are the airlines KAYAK users have selected most often from within our search results for flights to Ontario, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results for flights to Ontario, as well as popular online travel agencies
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Flight Deals

Cheap Flights from Greece to Ontario

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Greece to Ontario that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Greece to Ontario

Sat, Nov 8 - Mon, Nov 24
United Airlines Logo
6:30 am - 10:31 pmATH-ONT
26h 01m2 stops
United Airlines Logo
6:38 pm - 1:40 amONT-ATH
21h 02m2 stops
$826United Airlines
Find Deal
Wed, Oct 15 - Sun, Oct 19
American Airlines Logo
8:45 am - 10:42 pmATH-ONT
23h 57m2 stops
American Airlines Logo
8:15 am - 2:35 pmONT-ATH
20h 20m2 stops
$827American Airlines
Find Deal
Sat, Nov 8 - Sun, Nov 23
United Airlines Logo
6:30 am - 10:31 pmATH-ONT
26h 01m2 stops
United Airlines Logo
7:00 am - 1:25 pmONT-ATH
20h 25m2 stops
$828United Airlines
Find Deal
Sun, Nov 23 - Tue, Dec 9
KLM Logo
6:05 am - 5:09 pmATH-ONT
21h 04m2 stops
KLM Logo
12:12 pm - 4:35 pmONT-ATH
18h 23m2 stops
$831KLM
Find Deal
Thu, Oct 9 - Wed, Oct 22
KLM Logo
10:30 am - 8:19 pmATH-ONT
19h 49m1 stop
KLM Logo
7:05 am - 10:55 amONT-ATH
17h 50m1 stop
$840KLM
Find Deal
Wed, Oct 15 - Sun, Oct 19
Delta Logo
6:00 am - 5:10 pmATH-ONT
21h 10m2 stops
Delta Logo
7:05 am - 10:55 amONT-ATH
17h 50m1 stop
$841Delta
Find Deal
Thu, Nov 13 - Wed, Nov 26
KLM Logo
6:05 am - 5:09 pmATH-ONT
21h 04m2 stops
KLM Logo
11:44 am - 4:35 pmONT-ATH
18h 51m2 stops
$884KLM
Find Deal
Fri, Mar 27 - Tue, Mar 31
Delta Logo
12:20 pm - 11:38 amATH-ONT
32h 18m1 stop
Delta Logo
6:45 am - 5:05 pmONT-ATH
24h 20m2 stops
$954Delta
Find Deal
Sun, Oct 26 - Mon, Nov 3
Qatar Airways Logo
7:00 pm - 11:32 pmATH-ONT
37h 32m2 stops
Qatar Airways Logo
6:00 am - 11:10 amONT-ATH
43h 10m2 stops
$1,263Qatar Airways
Find Deal
Sun, Oct 26 - Sun, Nov 2
Qatar Airways Logo
7:00 pm - 8:53 pmATH-ONT
34h 53m2 stops
Qatar Airways Logo
5:00 am - 10:10 amONT-ATH
43h 10m2 stops
$1,293Qatar Airways
Find Deal

Everything you should know

Cheapest round-trip
$826
United Airlines
Sat 11/8Mon 11/24
ATH - ONT • 2 stops
Cheapest one-way
$555
Multiple Airlines
Thu 3/26
ATH - ONT • 3 stops
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Ontario!
Booking Insights

KAYAK's insights & trends for flights to Ontario

Get data-powered insights and trends for flights to Ontario to help you find the cheapest flights, the best time to fly and much more.

How long is the flight to Ontario?

The duration of your flight to Ontario depends on your departure and arrival airports. Obviously, any flights that include a layover will also be longer. The most popular routes to Ontario on KAYAK are from Athens, which takes 13h 30m, and Thessaloniki, which takes 17h 20m.

How many direct flights to Ontario are there each day?

There are around 86 direct flights from within Greece to Ontario every day. Most flights depart in the morning, with 8:00 am the most common departure time and 45% of flights departing in the morning.

Good to know

Cheapest flight$555
Flight from Athens to Ontario

FAQs - booking Ontario flights

  • How far is Ontario Airport from central Ontario?

    The city center of Ontario is 3 miles from Ontario Airport.

  • What is the name of Ontario’s airport?

    When flying to Ontario, you'll arrive at Ontario Airport (ONT). The airport is also known as Ontario or Ontario Intl.

  • How does KAYAK find such low prices on flights to Ontario?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights to Ontario.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket to Ontario?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights to Ontario?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Ontario with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight to Ontario?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • How many direct flights to Ontario are there each week?

    Each week there are around 602 direct flights from within Greece to Ontario. The most common day for departures is Sunday, with 16% of flights taking off on this day.

Top tips for finding cheap flights to Ontario

  • Enter your preferred departure airport and travel dates into the search form above to unlock the latest Ontario flight deals.

Reviews of the top airline flying from Greece to Ontario

 
See real verified KAYAK customer reviews for airlines flying to Ontario. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline from Greece to Ontario. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with to Ontario? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 8924 reviews
8.1Crew
7.1Entertainment
7.7Boarding
7.3Comfort
6.6Food
Airline reviews

Subject: Formal Complaint: Discriminatory and Unprofessional Conduct – Request for Immediate Action & Compensation Dear [Airline Customer Relations Team], I am writing to file a formal complaint regarding my recent travel experience with [Airline], which was by far the worst I have ever encountered. What occurred was not only unprofessional, but in several instances discriminatory, unsafe, and unacceptable. On the first leg of my trip, I arrived only four minutes past check-in. Instead of making any attempt to resolve the matter, your representative flatly denied me boarding and made me wait while she attended to passengers who arrived after me. By the time a manager intervened, it was too late to board, costing me time, money, and unnecessary frustration. The second leg of my trip (Chicago–San Francisco) raised even more serious concerns. From the outset, it was apparent that the staff—particularly two attendants—prioritized Caucasian passengers while dismissing African American and minority passengers. • When a Caucasian passenger in the exit row refused to comply with federal safety requirements, I, as a first responder, immediately offered to switch seats and assume the responsibility. My offer was blatantly ignored, and instead, a Caucasian passenger seated further up was chosen. This was discriminatory and deeply insulting, especially as I was actively de-escalating the situation that could have delayed the flight further. • During a lengthy tarmac delay of over 90 minutes, passengers were given conflicting and unreasonable instructions that created unnecessary distress and tension. • Throughout the flight, a visibly intoxicated passenger directly in front of me was disruptive, rude to others, failed to comply with seatbelt and electronic device rules, and yet faced no enforcement from the crew. In stark contrast, I was singled out for repeated compliance checks even though I was following every rule. This unequal treatment was so obvious that multiple passengers around me spoke up in my defense. This pattern of behavior demonstrated a clear lack of professionalism, disregard for passenger safety, and discriminatory treatment. I expect far better from an airline of your stature. As a paying customer subjected to this unacceptable treatment, I am formally requesting: 1. A full investigation into the conduct of the staff on both flights. 2. A written apology acknowledging the discriminatory and unprofessional behavior I endured. 3. Appropriate compensation for the distress, inconvenience, and mishandling of my travel. If this matter is not addressed promptly and thoroughly, I will have no choice but to escalate my complaint further, including filing with the U.S. Department of Transportation and sharing my experience through other channels. I trust [Airline] will take this complaint seriously and provide a timely resolution.

2.0 MediocreAnonymous, Sep 2025ORD - SFO
Read more United Airlines reviews

Subject: Formal Complaint: Discriminatory and Unprofessional Conduct – Request for Immediate Action & Compensation Dear [Airline Customer Relations Team], I am writing to file a formal complaint regarding my recent travel experience with [Airline], which was by far the worst I have ever encountered. What occurred was not only unprofessional, but in several instances discriminatory, unsafe, and unacceptable. On the first leg of my trip, I arrived only four minutes past check-in. Instead of making any attempt to resolve the matter, your representative flatly denied me boarding and made me wait while she attended to passengers who arrived after me. By the time a manager intervened, it was too late to board, costing me time, money, and unnecessary frustration. The second leg of my trip (Chicago–San Francisco) raised even more serious concerns. From the outset, it was apparent that the staff—particularly two attendants—prioritized Caucasian passengers while dismissing African American and minority passengers. • When a Caucasian passenger in the exit row refused to comply with federal safety requirements, I, as a first responder, immediately offered to switch seats and assume the responsibility. My offer was blatantly ignored, and instead, a Caucasian passenger seated further up was chosen. This was discriminatory and deeply insulting, especially as I was actively de-escalating the situation that could have delayed the flight further. • During a lengthy tarmac delay of over 90 minutes, passengers were given conflicting and unreasonable instructions that created unnecessary distress and tension. • Throughout the flight, a visibly intoxicated passenger directly in front of me was disruptive, rude to others, failed to comply with seatbelt and electronic device rules, and yet faced no enforcement from the crew. In stark contrast, I was singled out for repeated compliance checks even though I was following every rule. This unequal treatment was so obvious that multiple passengers around me spoke up in my defense. This pattern of behavior demonstrated a clear lack of professionalism, disregard for passenger safety, and discriminatory treatment. I expect far better from an airline of your stature. As a paying customer subjected to this unacceptable treatment, I am formally requesting: 1. A full investigation into the conduct of the staff on both flights. 2. A written apology acknowledging the discriminatory and unprofessional behavior I endured. 3. Appropriate compensation for the distress, inconvenience, and mishandling of my travel. If this matter is not addressed promptly and thoroughly, I will have no choice but to escalate my complaint further, including filing with the U.S. Department of Transportation and sharing my experience through other channels. I trust [Airline] will take this complaint seriously and provide a timely resolution.

Check in was quick and easy during early hours. Flight was on time, and customer services was a plus.

I understand that the food on the airplane wouldn’t be fantastic. However, it wasn’t good at all. 😭

The flight was comfortable with the exit row and great service

Plane was crowded and even when we hit altitude, the plane was hot, not enough air flow.

1. when we went to check in, our 2 first class seats had been CANCELED and the flight was sold out. This was done without our prior knowledge. It was all we could do to restore one first class seat for my wife and I flew economy. 2, Our flight home was scheduled to leave at 10:30 pm. Due to tsunami warnings, the roads were closed and our flight status was uncertain as to whether it would leave as scheduled. It was announced that it would now leave at 11:20 pm and the roads were now open since the tsunami had come and gone. We made a mad dash to the airport and checked in. Delays were announced at 12:30 pm, 1:30 am, 2:30 am and at 3:30 am it was canceled. Since this was a flight due to natural (tsunami) causes, there was no compensation. We were told to return at 1:00 pm the next day and our baggage would be kept on the plane since the same plane was going to leave at 1:00 pm. We had to return to our hotel for the rest of the night. The same plane did not leave at 1:00 pm and our baggage was gone! All in all, it was a miserable performance by UA. Information was hard to obtain and no one knew what was going on and what was going to happen. Hundreds of passengers slept on the floor, chairs, etc. No food and no water was made available to the passengers. It was a situation where UA could care less what was going on. As a one million mile flyer, I had not experienced anything like this before and it was hugely disappointing!

I found the staff to not be very attentive at all. When paying for Business Class you expect a certain type of service and that was not found. They were almost rude even

Ok. Get a different kosher caterer. The food was odd.

Our experience on United Airlines was extremely poor. The plane was extremely cold throughout our entire flight- which multiple people complained about- and we had to wait 2 hours to get a blanket which was too thin and barely helped warm us up. As well as this, none of the entertainment features were working so we had to sit through a roughly 10 hour flight with nothing to keep our attention, including the actual flight path screen. It was an extremely disappointing experience and I would hope that this gets fixed if we ever choose United Airlines again.

I really enjoyed flying with United airlines amazing experience , good customer service and great food

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario

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