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 3/6. 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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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

Thu, Apr 2 - Thu, Apr 2
Frontier Logo
7:00 am - 8:04 am
LAS
-
ONT
1h 04mnonstop
Frontier Logo
10:50 am - 12:03 pm
ONT
-
LAS
1h 13mnonstop
$54Frontier
Wed, Apr 15 - Tue, Apr 21
Frontier Logo
5:41 pm - 6:49 pm
LAS
-
ONT
1h 08mnonstop
Frontier Logo
7:44 pm - 8:54 pm
ONT
-
LAS
1h 10mnonstop
$56Frontier
Thu, Apr 2 - Mon, Apr 6
Alaska Airlines Logo
2:12 pm - 3:42 pm
STS
-
ONT
1h 30mnonstop
Alaska Airlines Logo
4:22 pm - 6:22 pm
ONT
-
STS
2h 00mnonstop
$95Alaska Airlines
Thu, Apr 2 - Mon, Apr 6
Alaska Airlines Logo
2:12 pm - 3:42 pm
STS
-
ONT
1h 30mnonstop
Alaska Airlines Logo
4:22 pm - 6:22 pm
ONT
-
STS
2h 00mnonstop
$97Alaska Airlines
Wed, Apr 15 - Wed, Apr 22
United Airlines Logo
10:50 am - 12:20 pm
SFO
-
ONT
1h 30mnonstop
United Airlines Logo
11:05 am - 12:34 pm
ONT
-
SFO
1h 29mnonstop
$117United Airlines
Tue, Apr 7 - Tue, Apr 14
Southwest Logo
6:25 pm - 7:40 pm
SJC
-
ONT
1h 15mnonstop
Southwest Logo
12:30 pm - 1:45 pm
ONT
-
SJC
1h 15mnonstop
$117Southwest
Tue, Apr 7 - Tue, Apr 14
Southwest Logo
7:15 am - 8:30 am
SJC
-
ONT
1h 15mnonstop
Southwest Logo
4:30 pm - 8:30 pm
ONT
-
SJC
4h 00m
1 stop
$127Southwest
Tue, Apr 7 - Thu, Apr 9
United Airlines Logo
6:00 am - 9:56 am
SMF
-
ONT
3h 56m
1 stop
United Airlines Logo
6:00 am - 9:38 am
ONT
-
SMF
3h 38m
1 stop
$188United Airlines
Wed, Mar 25 - Tue, Mar 31
Delta Logo
6:00 am - 4:28 pm
MFR
-
ONT
10h 28m
2 stops
Delta Logo
5:09 pm - 10:33 am
ONT
-
MFR
17h 24m
2 stops
$194Delta
Wed, Mar 25 - Tue, Mar 31
Delta Logo
11:13 am - 5:13 pm
MFR
-
ONT
6h 00m
1 stop
Delta Logo
5:09 pm - 10:33 am
ONT
-
MFR
17h 24m
2 stops
$245Delta
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Good to know

Low seasonJanuary
Cheapest flight$29
Best time to beat the crowds but there is an average 1% increase 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
Alaska AirlinesOverall score based on 11948 reviews
8.5Crew
7.0Entertainment
8.1Boarding
7.1Food
7.8Comfort
Airline reviews

I bought tickets MONTHS ago for a flight that left SAN at 14:30. That is what it says on our tickets. I was never notified of any time changes. During online check-in. I discovered the flight time had been changed to 15:45. This was unacceptable and had I been notified, I would have changed flights, or airlines. That departure time was unworkable with our plans. We called Alaska and asked for an explanation. They said flight time was changed 11/08/25. No proof of notification could be offered. We asked to be moved to an earlier flight. After much pleading, the rep said she would allow a “one time exception..” While I appreciate being moved, this was YOUR fault Alaska Airlines.

2.0 MediocreLinda, Feb 2026
SAN - SMF
Read more Alaska Airlines reviews

I bought tickets MONTHS ago for a flight that left SAN at 14:30. That is what it says on our tickets. I was never notified of any time changes. During online check-in. I discovered the flight time had been changed to 15:45. This was unacceptable and had I been notified, I would have changed flights, or airlines. That departure time was unworkable with our plans. We called Alaska and asked for an explanation. They said flight time was changed 11/08/25. No proof of notification could be offered. We asked to be moved to an earlier flight. After much pleading, the rep said she would allow a “one time exception..” While I appreciate being moved, this was YOUR fault Alaska Airlines.

I love Alaska! We arrived on the later side without seat assignments only to find the had oversold the flight by 1. The attendants worked extra hard to find a way for our party of 7 to stay together and we made it on the flight! Loved the free WiFi also!

The he whole flight was very smooth on every aspects.

Due to plane delays on both legs of my flight home, I had to be rerouted from Santa Rosa to Las Vegas on Skywest and then to DCA on American. SkyWest airlines sat on runway in Las Vegas for 20 minutes waiting for gate to clear. My boarding pass for American that I was given by Alaska was incomplete and the Las Vegas airport lacked signage and departure boards. I barely made my flight bc it was so confusing. American Airlines has a much better wireless connection. I’ll never fly Alaska again. It clearly has problems.

I paid for wifi and it never worked... it was miserable. I couldn't access my shared files to work on the plane, it didn't work on my phone. I paid for nothing but frustration and continual refreshing, hoping it would work

Again, very smooth and all of the Alaska folks were great. They continue to meet all my needs.

Overall it was fine, however one of my two checked bags did not arrive and I was told it was left in Palm Springs. I don't understand how one of the two bags made it through fine but the other got lost .

The whole experience went smoothly with no hitches along the way.

The flight was excellent and very friendly and helpful staff. Will travel again and recommend to friends. Thank you

Did not have In flight service on my round trip due to turbulence. I did not partake in In flight entertainment. Flight descending into LAX was very turbulent. It would have been nice if the pilot communicated with us during that rough descent into LAX to ease the minds of some of us more nervous flyers.

The charges were ridiculous for an hour flight and the turbulence was very scary.

3 hour delay. Had to change plans and was still delayed.

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!

Overall we had a good experience during our flight from San Francisco to Houston.

it was a very short flight so my expectations were low.

Very disappointing given gate agent behavior. Filed a formal complaint with United.

Flight delayed. WiFi connectivity very poor if not existant. Last minute arrival forced me to run to catch my connection.

The power at the seat didn't work and the seat itself was difficult to adjust - this was a business class seat. Flight attendant gave me miles to compensate. The attendant was very professional and on top of his game the entire flight.

the whole trip was smooth, and as comfortable as flying is these days. flight crew was friendly and very courteous and helpful.

First class ticket gets you a choice of chips or nuts. . Just like economy Southwest. Also no screen in the seats. This is first class???!

Flight arrived 30 min early and bag was waiting at the baggage pickup. United Club HNL was one of the nicest in the system

Yet another flight in which beverage and snack service was skipped. Other that that, firmly mediocre. Landed early, to gate late due to congestion at the gates. Airline's fault or airports fault: unknown.

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

The flight was significantly delayed for 6.5 hours because of snow. There was no communication once the plane returned to the gate regarding when the flight would resume. Other flights were departing while our flight was being unloaded for reasons unknown. Our flight also seemed out of the queue regarding further deicing, refueling, and waiting to Taxi to the runway.

They are always late and seats was also not having working charger

did not have enough meal for first class passengers so offer us snack

Amazing I love American. I’ll never fly anyone else if I can help it.

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

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

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.

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario