$43 Find Cheap Flights from North America 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 1/23. 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, 0 bags

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Everything you should know

Cheapest round-trip
$70
Overall average: $177
Frontier
Tue 2/24Thu 2/26
DEN - ONT • Non-stop
Cheapest one-way
$43
Typical prices: $49-$159
Frontier
Fri 1/23
DEN - ONT • Non-stop
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Flight Deals
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Flight Deals

Cheap Flights from North America to Ontario

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from North America 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 North America to Ontario

Tue, Feb 24 - Thu, Feb 26
Frontier Logo
8:00 pm - 9:34 pm
DEN
-
ONT
2h 34mnonstop
Frontier Logo
6:05 am - 9:25 am
ONT
-
DEN
2h 20mnonstop
$70Frontier
Wed, Jan 14 - Sun, Jan 18
Frontier Logo
9:20 pm - 10:59 pm
DEN
-
ONT
2h 39mnonstop
Frontier Logo
6:10 am - 9:30 am
ONT
-
DEN
2h 20mnonstop
$72Frontier
Sat, Jan 17 - Sun, Jan 18
Frontier Logo
9:20 pm - 10:59 pm
DEN
-
ONT
2h 39mnonstop
Frontier Logo
6:10 am - 9:30 am
ONT
-
DEN
2h 20mnonstop
$73Frontier
Wed, Jan 14 - Sat, Jan 17
Alaska Airlines Logo
6:00 pm - 8:36 pm
SEA
-
ONT
2h 36mnonstop
Alaska Airlines Logo
4:03 pm - 6:54 pm
ONT
-
SEA
2h 51mnonstop
$128Alaska Airlines
Sat, Jan 17 - Sun, Jan 18
Delta Logo
5:25 am - 12:16 pm
SEA
-
ONT
6h 51m1 stop
Delta Logo
7:30 am - 10:36 am
ONT
-
SEA
3h 06mnonstop
$129Delta
Sat, Jan 31 - Sun, Feb 1
Alaska Airlines Logo
12:43 pm - 7:16 pm
SEA
-
ONT
6h 33m1 stop
Alaska Airlines Logo
6:00 am - 8:54 am
ONT
-
SEA
2h 54mnonstop
$132Alaska Airlines
Sat, Jan 17 - Sat, Jan 24
American Airlines Logo
6:30 am - 12:03 pm
JFK
-
ONT
8h 33m1 stop
American Airlines Logo
12:57 pm - 10:59 pm
ONT
-
JFK
7h 02m1 stop
$247American Airlines
Tue, Jan 13 - Tue, Jan 20
American Airlines Logo
10:35 am - 2:18 pm
HOU
-
ONT
5h 43m1 stop
American Airlines Logo
10:58 am - 10:46 pm
ONT
-
HOU
9h 48m1 stop
$329American Airlines
Mon, Jan 19 - Mon, Jan 26
Southwest Logo
7:45 am - 9:20 am
HOU
-
ONT
3h 35mnonstop
Southwest Logo
5:15 am - 10:15 am
ONT
-
HOU
3h 00mnonstop
$333Southwest
Mon, Jan 19 - Mon, Jan 26
Southwest Logo
7:45 am - 9:20 am
HOU
-
ONT
3h 35mnonstop
Southwest Logo
3:25 pm - 10:15 pm
ONT
-
HOU
4h 50m1 stop
$343Southwest
Useful Info

Good to know

Low seasonSeptember
Cheapest flight$43
Best time to beat the crowds with an average 5% drop in price.
Most popular time to fly and prices are also 1% lower on average.
Flight from Denver to Ontario

Flights from North America to Ontario: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from North America to Ontario 
Verified travelerFlew with Hawaiian Airlines
SEA
-
ONT
Jun 2025
Make sure to be there on time because the bag drop off can be a little complicated and it takes quite some time to get to the gate.
Verified travelerFlew with Alaska Airlines
SEA
-
ONT
Oct 2024
SeaTac lets you make an appointment to get through security. SpotSaver. No cost. Online.
JoelFlew with American Airlines
DFW
-
ONT
May 2024
Dallas is a very spread out airport, jus make sure that you have enough time to transfer during layovers. Also all the restaurants close fairly early

FAQs for booking flights from North America to Ontario

  • How does KAYAK find such low prices on flights from North America 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 from North America to Ontario.

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

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

  • What is the Hacker Fare option on flights from North America 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 to North America with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from North America 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 from North America up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines serving from North America to Ontario

 
Need help choosing which airline to fly with from North America 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.
8.0
SouthwestOverall score based on 4257 reviews
8.1Boarding
8.6Crew
7.0Food
8.0Comfort
7.5Entertainment
Airline reviews

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

8.0 ExcellentRussell, Dec 2025
SAN - OAK
Read more Southwest reviews

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

Still a fan of open seating. Flight was on schedule and arrived on time. The 737 MAX is very comfortable.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

Delays delays delays. Late taking off, late landing, wait for a gate, etc.

Connecting flight is on time and boarding was a breeze!

Very smooth checking in our luggage with a super pleasant SW agent. I enjoyed a fun entertaining movie.

First time traveling on Southwest since bag fees were implemented. Usual good service. Just more expensive now.

It was a perfect flight in all aspects! Both legs!

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

They changed planes and the new plane couldn’t carry enough fuel to fly across the country so we had to stop in Kansas City to refuel. Flight was delayed .

Flight was too crowded and seats are too small, especially since passengrs are getting larger. Having a middle seat is ALWAYS tough! Woman on my left was large & kept creeping in to my space. Flight personnel were great! Have more savory rather than sweet snacks please.

The crew took good care of us. The flight from ATL to SFO is a longer one, and there were multiple beverage offerings. I like the 757's that Delta uses. Good airplane that is comfortable. I do wish Delta would separate Priority boarding from the better seats. I would gladly take a smaller seat in an open row than be jammed into Comfort just to get priority boarding, just to make sure I don't have to check a bag.

The crew was not very visible. This might be a good thing for people who wanted to sleep but seemed odd when compared to the Atlantic crossing where they are more present in the cabin. The Food (beef) was not good. Tough and tasteless. Would love to see more choices on a long flight like that.

Gate agent rushed to fill hot jetway with crowd so it took over 12 minutes to go from gate to plane. Just like a discount airline Pooly prepared cabin and third time that claim of rough air prevented any cabin service. Friends on a Southwest flight at similar time had service.

The flight crew was friendly. I tried to adjust my seat online ahead of time but no option existed without additional fees. My friend asked at the gate about a seat change and was able to make it happen. That was great! The flight crew moved a very tall gentleman and his companion which allowed us to have more space which was nice. Overall, good experience. Appreciated the blanket and pillow.

I was uncomfortably cold on the plane. Other than that it was uneventful and therefore as enjoyable as a plane ride can be.

Food was surprisingly good but the WiFi was not great

My flight was extremely cold. I had a jacket and a cover was left in each seat. The cover was extremely thin and I have a disability, fibromyalgia and arthrithis and AC air is the worst. I closed my vent and my husbands vent and it still was frigid. I asked the attendant if I could get another cover and she quickly almost dismissively and totally unconcerned stating, (I quote) (one per chair) and walked off so quickly that I didn't get a chance to explain to her that I literally have adisability. I didnt want to make a seen so I set on that flight for over 5 hours in pain, joints locking up and extremely uncomfortable. When my fibromyalgia flares up my joints not only ache but they will lock up also and it takes me days to get back to my regular self even though I take medication for it. I felt like it would not have hurt anyone at all for her to just give me an extra cover because I'm sure they have all types of medical issues in people that fly every day.

Flight was late - I was downgraded from first class to coach

Movie selection is good. Crew did not understand mileage program and were no help. Sick later. Food?

United needs to step up their game. Delayed flight leaving Seattle, San Francisco. Older aircraft, not very comfortable.

The flight attendants were very rude, beyond comprehension. I took a business class from London to SFO for the first time on United. When I asked for a second piece of bread during dinner, the serving attendant threw a 3rd bread on my plate and said, “here. You can have this one too”! I couldn’t believe the rudeness of the attendant. Most all attendants were very rude, unhelpful, sing the food was absolutely disgusting. Never fly United internationally in business class. My flight back to SFO was a nightmare!!

Plane boarded early a quickly, was mostly full. We left close to on time. And landed early.

7 hours delayed due to operational issues on United’s end. Basically laziness.

Flight from Rome to SFO was excellent compared To our flight to Europe from SFO. The food was much tastier. You can see how UNITED is skimping, though. Instead of getting something mid flight you had to ask for it. It was not automatically served. There was a cookie at the end of the arrival meal, for example that tasted like it just came out of a box. They used to serve a little container of nuts, now … a tiny container of nuts, mixed with pretzels. This was business class that you really have to pay for! But this is minor complaints compared to the overall. My major complaint is the position of the even numbered seats by the windows. You have to turn around to see your window & the positioning as some other controls are harder to get at. This is compared to the odd number seat that are perfectly aligned.

The food quality sucks. One must starve if they do not eat flesh Or wheat based products Some variety would be expected. The trivial amount of snacks and or food is inhumane

Flight was timely, relatively comfortable, with decent entertainment and food served. Only problem encountered was with the free messaging which I highly appreciate, but it did not work from iphone to non-iphones.

The internet service I paid for didn’t work at all and the flight crew was not very friendly.

We were told the flight was delayed 5 times, then it was moved to the next day.

The experience with American Airlines was good, although the Philippines Airlines flight was much better (better seats, better food, better entertainment options, overall better). Again, the MIA to LAX flight was fine, but nothing in comparison to the comfort and accommodations of the Philippines Airlines flight from LAX to MNL.

Loved the crew . Absolutely no complaints. Except for luggage lost

Wish some foods provided rather than just biscuit/cookie for flight more than 2 hours

We are too tired and frustrated to comment politely at this point

The business class seats are dated and uncomfortable. The space is bare minimum and there is absolutely no privacy. For $4K, this is not what I expect.

The flight crew was rude. We were in first class and no one even offered water until an hour after we were in the air. Horrible experience

Great. Quick and quiet and east. The breakfast choices were a welcome surprise!

The stewardess hit me with the food kart twice on the head and didn't say I'm sorry once. The same stewardess gave me a warm Apple Juice with No ice. The Flight was delayed for Departure 6 times, starting from 2:36pm, finally taking off 7:50pm. I was late picking up my child from the sitter by 3 hours.

Did not get the seat I selected and paid for.

Not clean and was told I would get a great seat and it was not great at all

Good- no snacks on a 4+ hour flight is painful but more painful was the lack of WiFi.

Flight got delayed for 5 hours no good explanation was offered ;(

Horrible. I would never fly Frontier again. The booking process is tricky at best, but fraudulent in my opinion. Frontier customer service did nothing to rectify my purchase -- I ended up paying more than double what I could have gotten from other airlines and nearly triple what I thought I was buying from Frontier. Their booking practices are unfair to the consumer.

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

Better than expected. Staff were friendly and nice on both flights.

There was no one at the counter to assist with our check in. The app didn’t work, so I arrived at the airport with time to check in and I couldn’t because no employees were there. When I finally got someone on the phone, it was inside the 60min rule and they said I could no longer check in and they could sell me another ticket. We had to scramble and pay an additional $800 for tickets and THEN AFTER (about 60 min from my original convo with customer service and 10min after original departure time) I had boarded my new flight, there was email saying my original flight from Frontier was delayed and leaving 2hr 50min later, but I STILL wouldn’t have been able to check in. Which means customer service should have been able to see it and let me check in because I was well within my check in time. When I call Frontier, they hang up on me. So their app didn’t work and they employees left and they take zero responsibility or assistance with their “customer service”

Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.

No fault of Frontier staff: plane was very late, reached Orlando at 1 am, took a while to get luggage. Weather, gov financial shutdown impact on TSA, air controllers seemed to have multiple flights backed up. Frontier staff seemed to cope as gracefully as possible. It did reassure me that I and my new hip could adapt to travel challenges. Food/entertainment were irrelevant to my trip.

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario