ONT

$29 Find Cheap Flights from California 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 2/6. 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
$57
Overall average: $71
Frontier
Sat 2/7Sat 2/7
LAS - ONT • Non-stop
Cheapest non-stop
$57
Typical prices: $52-$102
Frontier
Fri 1/30Sun 2/1
LAS - ONT • Non-stop
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Flight Deals
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Flight Deals

Cheap Flights from California to Ontario

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

Sat, Feb 7 - Sat, Feb 7
Frontier Logo
12:23 pm - 1:34 pm
LAS
-
ONT
1h 11mnonstop
Frontier Logo
7:35 pm - 8:44 pm
ONT
-
LAS
1h 09mnonstop
$57Frontier
Wed, Jan 28 - Fri, Feb 6
Frontier Logo
1:01 pm - 2:12 pm
LAS
-
ONT
1h 11mnonstop
Frontier Logo
8:48 pm - 9:56 pm
ONT
-
LAS
1h 08mnonstop
$58Frontier
Thu, Jan 29 - Sun, Feb 1
Frontier Logo
6:45 pm - 7:53 pm
LAS
-
ONT
1h 08mnonstop
Frontier Logo
5:21 pm - 6:32 pm
ONT
-
LAS
1h 11mnonstop
$59Frontier
Thu, Feb 5 - Sun, Feb 8
American Airlines Logo
4:23 pm - 10:13 pm
STS
-
ONT
5h 50m1 stop
American Airlines Logo
6:22 am - 12:25 pm
ONT
-
STS
6h 03m1 stop
$170American Airlines
Mon, Mar 23 - Tue, Mar 24
Southwest Logo
6:00 am - 7:20 am
OAK
-
ONT
1h 20mnonstop
Southwest Logo
5:45 am - 7:10 am
ONT
-
OAK
1h 25mnonstop
$189Southwest
Mon, Mar 23 - Tue, Mar 24
Southwest Logo
6:00 am - 7:20 am
OAK
-
ONT
1h 20mnonstop
Southwest Logo
4:25 pm - 9:35 pm
ONT
-
OAK
5h 10m1 stop
$199Southwest
Wed, Jan 28 - Thu, Jan 29
American Airlines Logo
5:32 am - 12:03 pm
MFR
-
ONT
6h 31m1 stop
American Airlines Logo
12:57 pm - 7:38 pm
ONT
-
MFR
6h 41m1 stop
$217American Airlines
Tue, Feb 17 - Tue, Feb 24
Delta Logo
11:30 am - 11:49 pm
MFR
-
ONT
12h 19m2 stops
Delta Logo
7:30 am - 10:50 am
ONT
-
MFR
27h 20m1 stop
$230Delta
Sat, Feb 7 - Sat, Feb 14
United Airlines Logo
6:40 am - 12:17 pm
MRY
-
ONT
5h 37m1 stop
United Airlines Logo
1:53 pm - 5:20 pm
ONT
-
MRY
3h 27m1 stop
$239United Airlines
Tue, Feb 10 - Sat, Feb 14
United Airlines Logo
5:00 am - 12:47 pm
MRY
-
ONT
7h 47m1 stop
United Airlines Logo
1:53 pm - 5:20 pm
ONT
-
MRY
3h 27m1 stop
$299United Airlines
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$29
Best time to beat the crowds with an average 7% drop in price.
Most popular time to fly with an average 3% increase in price.
Flight from Las Vegas to Ontario

FAQs for booking flights from California to Ontario

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

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Ontario from California 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 California 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 California with another airline.

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

 
Need help choosing which airline to fly with from California 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 4249 reviews
8.0Comfort
7.5Entertainment
8.1Boarding
7.0Food
8.6Crew
Airline reviews

The flight crew was extremely rude and especially not helpful when our flight was delayed.

2.0 MediocreMatthew, Jan 2026
DAL - SAN
Read more Southwest reviews

The flight crew was extremely rude and especially not helpful when our flight was delayed.

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.

I really liked the legroom. I am 6’4”.a at For some reason our seats were not together and using the app to fix it didn’t work. Passengers were nice enough to move for us but you should absolutely ensure a parent sits with their child.

The flight was delayed for about 2 hrs. Other than it, it was good.

I am extremely disappointed that delta internal pilot manuals now refer to the Gulf of Mexico as the “gulf of America”. You can bow down to the Orange turd on your own. I will never fly delta again

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

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.

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.

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

Teeny tiny bathrooms, crew was not realistic about when we'd arrive.

Unbelievably poor service from flight attendants. They didn’t even do water service on a four hour flight. Just disrespectful.

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

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

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 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.

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.

Everything about the flight was lovely. My only suggestion would be to offer a few more options of tv series from Apple TV or HBO.

After the door had been closed, the cockpit makes an announcement that catering is running late and it is not the airline's fault. It is their fault in the sense that we had to sit for 2 hours or more when we could have stayed in the terminal. Poor communications between catering and airline. This caused a young man to lose his temper and he went storming out hitting objects. He had complained to the gate agent that he had already waited at the gate 7 hours and when can the airplane leave? Airilnes do a poor job of explaining delays, maintenance issues, etc. whereas being truthful may gain more sympathy or understanding.

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 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.

It was ok. It was expensive to check 2 bags ($75.00 per bag), and then it took a long time to wait for shuttle to take us from one terminal to the terminal where the plane was taking off at LAX. And all of this for a flight where we had to pay for any food or drink that was not water.

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.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

i was unable to check in the flight. refund requested

I think Frontier was very good at communication. Their app worked very well. Loading was great and the flight was nice and easy.

This airline sucks. They offer low rates then charge you for everything, the app does not work well, the seats are the most uncomfortable. Maintenance issues on the flight, and you still have to sit through their credit card commercials. People are nice enough but does not make up for overall poor experience.

Great for the price. No wifi or entertainment, but gate agents and crew were fantastic and we boarded quickly and left on time.

Decent clean onboard experience. Okay discount airline experience. Unfortunately, any customer service interactions are difficult and unhelpful. There is no service. Also, a premium seat only gets you premium boarding if you line up first. Once they start general boarding you must go to the back of the line. Not very premium

The crew was mostly okay. The flight attendant who answered our questions was curt and unhelpful unfortunately. He seemed upset and I understand having off days.

Very bad! No good service delayed my second connection flight

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario