ONT

$28 Find Cheap Flights to Ontario - Compare and Save

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Everything you should know

Cheapest round-trip
$64
Typical prices: $240-$497
Frontier
Mon 10/15Fri 10/19
SFO - ONT • Non-stop
Cheapest one-way
$28
Typical prices: $139-$314
Frontier
Sat 10/20
DEN - ONT • Non-stop
Nonstop flights
You can fly direct with Southwest, American Airlines and others. Average duration is 2h 19m.
FAQs
FAQs
Top airlines
Most flights • 228 per week
Best reviews • 8.0 score
Airline reviews
+1
Airline reviews
+1
Top routes
Cheapest • 61% average savings
Most popular
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 7 weeks in advance save around 30% compared to booking last minute.
Insights
Insights
When to travel
Cheapest • 18% price drop
Most popular
Good to know
+1
Good to know
+1
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We hope you love your trip to Ontario!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights to Ontario

 
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals to Ontario

Fri, Nov 6 - Mon, Nov 9
Frontier Logo
6:02 pm - 7:28 pmSFO  San Francisco-ONT Ontario
1h 26mnonstop
Frontier Logo
12:01 pm - 1:36 pmONT  Ontario-SFO San Francisco
1h 35mnonstop
$64Frontier
Thu, Oct 15 - Mon, Oct 19
Frontier Logo
6:02 pm - 7:40 pmSFO  San Francisco-ONT Ontario
1h 38mnonstop
Frontier Logo
12:01 pm - 1:32 pmONT  Ontario-SFO San Francisco
1h 31mnonstop
$64Frontier
Wed, Nov 4 - Wed, Nov 4
United Airlines Logo
11:00 am - 12:29 pmSFO  San Francisco-ONT Ontario
1h 29mnonstop
United Airlines Logo
1:35 pm - 3:05 pmONT  Ontario-SFO San Francisco
1h 30mnonstop
$113United Airlines
Sat, Oct 24 - Sat, Oct 31
United Airlines Logo
9:25 pm - 10:51 pmSFO  San Francisco-ONT Ontario
1h 26mnonstop
United Airlines Logo
6:00 am - 7:30 amONT  Ontario-SFO San Francisco
1h 30mnonstop
$117United Airlines
Wed, Oct 14 - Sat, Oct 17
Multiple Airlines Logo
10:29 pm - 11:50 pmDEN  Denver Intl-ONT Ontario
2h 21mnonstop
Multiple Airlines Logo
2:13 pm - 10:37 pmONT  Ontario-DEN Denver Intl
7h 24m1 stop Seattle/Tacoma Intl
$122Multiple Airlines
Tue, Oct 20 - Tue, Oct 27
Multiple Airlines Logo
9:01 am - 10:29 amDEN  Denver Intl-ONT Ontario
2h 28mnonstop
Multiple Airlines Logo
7:25 am - 2:32 pmONT  Ontario-DEN Denver Intl
6h 07m1 stop Portland
$123Multiple Airlines
Tue, Oct 20 - Wed, Oct 21
Southwest Logo
5:20 am - 9:45 amSFO  San Francisco-ONT Ontario
4h 25m1 stop Phoenix Sky Harbor Intl
Southwest Logo
4:15 pm - 9:40 pmONT  Ontario-SFO San Francisco
5h 25m1 stop Las Vegas Harry Reid Intl
$151Southwest
Wed, Nov 4 - Wed, Nov 4
Southwest Logo
5:05 am - 9:20 amSFO  San Francisco-ONT Ontario
4h 15m1 stop Phoenix Sky Harbor Intl
Southwest Logo
5:00 pm - 9:25 pmONT  Ontario-SFO San Francisco
4h 25m1 stop Las Vegas Harry Reid Intl
$151Southwest
Sat, Oct 24 - Mon, Oct 26
American Airlines Logo
1:30 pm - 6:43 pmLAS  Las Vegas Harry Reid Intl-ONT Ontario
5h 13m1 stop Phoenix Sky Harbor Intl
American Airlines Logo
1:05 pm - 6:25 pmONT  Ontario-LAS Las Vegas Harry Reid Intl
5h 20m1 stop Phoenix Sky Harbor Intl
$199American Airlines
Sat, Oct 17 - Mon, Oct 19
American Airlines Logo
1:30 pm - 6:43 pmLAS  Las Vegas Harry Reid Intl-ONT Ontario
5h 13m1 stop Phoenix Sky Harbor Intl
American Airlines Logo
1:05 pm - 6:22 pmONT  Ontario-LAS Las Vegas Harry Reid Intl
5h 17m1 stop Phoenix Sky Harbor Intl
$199American Airlines
Booking Insights

Price, demand and travel trends for flights to Ontario

Use KAYAK data on prices, travel dates, airlines and seasonal trends to compare options and book flights with more confidence.

What is the cheapest flight to Ontario?

San Francisco to Ontario is the cheapest route at $64 round-trip, found in the past 5 days on KAYAK. KAYAK data shows this is also the most popular route.

How much is a flight to Ontario?

On average, a round-trip flight from the United States to Ontario costs $358, based on KAYAK data over the past 12 months. Round-trip fares from Las Vegas average $130, while San Francisco runs a bit higher at $198.

What is the cheapest day to fly to Ontario?

Thursday is the cheapest day to fly to Ontario at $365 round-trip on average over the past 12 months on KAYAK. Sunday is the most expensive at $435.

What’s the cheapest month to fly to Ontario?

•October is the cheapest month to fly to Ontario with an average price of $294 round-trip.
•June ($423) and July ($407) are the most expensive.

Based on KAYAK data over the past 12 months.

What is the cheapest time of day to fly to Ontario?

Night flights to Ontario are the cheapest at $344 round-trip on average. Evening flights are the most expensive at $397.

What is a good deal for flights to Ontario?

Flights under $240 are considered a good deal. 25% of KAYAK users found round-trip flights to Ontario at or below these prices, with the lowest fares from:
•Las Vegas $78
•Denver $134
•San Francisco $136.

When are flights to Ontario the cheapest?

Flights to Ontario are cheapest 7 weeks before departure. Booking in this window typically costs about 30% less than the average last-minute fare (within 2 weeks of the flight), based on KAYAK data.

Expert advice

Expert advice for your flight to Ontario

 
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Frontier, United Airlines and Delta

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Harriet Baskas

Harriet Baskas

Expert on American Airlines and Alaska Airlines

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Jennifer Simonson

Jennifer Simonson

Expert on ONT

Jennifer Simonson is driven by her lifelong commitment to exploring the globe. Her insatiable curiosity had led her to immerse herself into diverse locations like Oklahoma City and Pismo. Her hotel recommendations are the result of the myriad hotels she's stayed at across her travels. Along her journey, she cherishes engaging conversations with locals, indulging in the finest ice cream, trying her hand at surfing, and embarking on nature-filled hikes.

Key details for flights to Ontario

Low season

February

Cheapest flight

$28
Beat the crowds with an average 16% drop in travelers.
The most popular month to fly with an average 23% increase in travelers.
One-way flight from Denver to Ontario

When to book flights to Ontario

Are your dates flexible? Find out the best times to travel to Ontario based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

Flights to Ontario: the best tips from KAYAK users' own experiences

Insights shared by verified travelers who flew to Ontario 
StevenFlew with Southwest-Jun 2026
Ontario airport is always easy to access, quick security lines, organized airport.
FraxysFlew with American Airlines-Feb 2026
Bring your own snacks or sandwich for dinner in the plane.

Your questions about flights to Ontario, answered

Find helpful route details based on KAYAK data, including flight times, airports, airlines and booking questions.

  • How do I know if a flight to Ontario is a good deal?

    A good deal on a flight to Ontario is around $240 round-trip. This fare is in the lowest 25% of round-trip prices searched on KAYAK, averaged across the cities most often searched as origins by KAYAK users.

  • How far is Ontario from downtown Ontario?

    Ontario is 3.1 mi from downtown Ontario.

  • How long are nonstop flights to Ontario from different departure cities?

    Nonstop flight time to Ontario varies depending on your departure city:

    • From Portland: 2h 16m
    • From Houston Hobby Airport: 3h 10m
    • From Atlanta: 4h 22m
    • From Charlotte: 5h 09m
    • From Honolulu: 5h 15m

  • How expensive are last-minute flights to Ontario?

    Last-minute fares to Ontario (booked within 2 weeks of departure) are typically 5% higher than the average round-trip fare of $358.

  • What is the difference between the most popular and the most frequent airline at Ontario?

    Southwest operates the most flights from the United States to Ontario at 228 per week, while Frontier is the airline most often selected by KAYAK users searching for flights from the United States to Ontario. The two are often different because flight volume reflects an airline's schedule, while popularity reflects traveler choice.

  • Which airlines should I consider for flights to Ontario?

  • How many flights serve Ontario?

    Ontario receives 76 flights per day and 529 per week from across the world. Phoenix Sky Harbor Intl Airport has the most flights to Ontario, with 62 weekly flights.

  • Are there good restaurants in Ontario International Airport?

    Passengers with flights to Ontario have several options when it comes to where to eat. Look for Schlotzsky’s Deli, El Paseo Cafe and Bar, and Route 66. You will find the restaurants and vending machines in Terminals 2 and 4.

  • Are there good malls or shopping places close to Ontario International Airport?

    Ontario Mills is the largest shopping mall and outlet mall in the Ontario area. Look for a variety of shops at Ontario Mills including Bath & Body Works, North Face, Coach, Polo, and Saks. Or, stop by the movie theater and enjoy a movie in between flights.

  • What kind of services does Ontario International Airport offer?

    At the airport, you can find shopping and dining options, free WiFi for up to 4 hours, cell phone parking lots, an inter-terminal shuttle, and a military lounge. Baggage carts are located for your use throughout the airport.

  • Do hotels in Ontario offer free shuttle service from Ontario International Airport?

    If you are looking for free shuttle service from the airport to a local hotel, you have two choices. Both Azure Hotel and Suites and Red Roof Inn Ontario offer free shuttle service to guests. They are both located approximately 5 minutes from the airport.

  • What is the best way to get from Ontario International Airport to Salt Oasis?

    Salt Oasis is located 6.1 miles from Ontario International Airport. The trip will take approximately 10 minutes by taxi by I-15N. Once you arrive, you can enjoy a salt bath and the salt caves. This is a relaxing way to spend time between flights or a way to de-stress before heading on to your final destination.

  • Can I take a rideshare from the Ontario International Airport (ONT) to my final destination?

    Yes, you can order an app-based rideshare once you land and have claimed your baggage. After baggage claim, follow the signs for “Ride-Share Pickup Location” and these are located near the east end of each passenger terminal.

  • Does the Ontario International Airport (ONT) have services for travelers with limited mobility?

    Yes, ONT offers several services for passengers with reduced mobility. These include wheelchair rental and assistance navigating the airport after landing, as well as services for deaf and visually impaired travelers. Contact your airline in advance if you will need to utilize any of these services.

  • Can I fly directly to the Ontario International Airport (ONT) from any other major US hubs?

    Yes, you will find plenty of direct flights to Ontario from major US cities. For example, United Airlines and Frontier Airlines both operate direct flights from Denver (DEN) to Ontario. You will also find direct flights on board JetBlue from New York City’s JFK airport. Alaska Airlines also offers a direct flight from Seattle to Ontario.

  • What other cities are served by the Ontario International Airport (ONT)?

    The ONT airport mostly serves the city of Ontario, but there are many cities and attractions nearby that it serves, as well. These include Riverside and San Bernardino, as well as the San Bernardino National Forest. It is also quite close to Anaheim, Los Angeles, and Pasadena, California.

Your guide to booking Ontario flights

From booking to airport arrival, find tips to help you plan your flight with more confidence.
  • For the best chance at a low fare to Ontario, book around 7 weeks before departure. Based on KAYAK data from the last 12 months, fares are historically about 30% lower during this window than last-minute fares.
  • For flights to Ontario, a good round-trip fare is around $240. If you find a fare below that, you're getting a strong deal.
  • If your travel dates are flexible, consider flying to Ontario in October. Round-trip fares historically average $294, making October the cheapest month to travel based on KAYAK data from the last 12 months.
  • Before you book:

    • Check the route's typical price range so you can spot a deal.
    • Confirm baggage fees and seat-selection costs on budget carriers.
    • Verify whether you need any travel documents beyond ID.
    • Pick a departure airport, since your nearest may not be the cheapest origin.
  • Shift your departure to evening to save up to $53 per round-trip. Evening flights to Ontario average $344 compared to $397 for afternoon flights.
  • Bag allowances vary by airline, fare type, cabin class and route. On flights to Ontario, some airlines may include bags at no extra cost. For example, Frontier includes a cabin bag and a checked bag in Economy Class, Southwest includes a cabin bag and a checked bag in Economy Class and Alaska Airlines includes a cabin bag and a checked bag in Economy Class. Always check the fare details before booking, since bag policies can change by ticket type.
  • Once you arrive in Ontario, a few great places to start are Ontario Convention Center and Cucamonga-Guasti Regional Park. These are popular with first-time visitors and can give you a good feel for the area.
  • Passengers that book flights to Ontario will want to take advantage of the free shuttle provided by the airport. The Ontario Courtesy Shuttle will take passengers between the terminals, parking lot 5, and the Consolidated Rental Car Facility. Shuttle services operate 24 hours a day.
  • Those that are in the military will want to stop by the USO Lounge. Access to the lounge is free to all active military and their families. In the lounge, you can find a TV, snacks, computers, a child care area, and a library. It is open from 6 a.m. to 10 p.m. and can be found in the West Wing for passengers who want somewhere quiet to wait between flights.
  • If you’re picking up or dropping people off at Ontario International Airport, check out the free cell phone lots. You can park there for free while you drop off or wait for your passengers. This area is designed to prevent people from circling the airport endlessly. You can park for free for one hour. No overnight parking allowed.
  • It’s easy to get to and from Ontario International Airport using a variety of transportation options. Look for the car rental services in ConRac which can be reached using the free shuttle service. Or, look for the shuttle, bus, taxi, or train services near the baggage claim area.
  • If you’re looking for business services while you’re at Ontario International Airport, you’ll want to visit the airport hotel located 6 minutes away. The Ontario Airport Holiday Inn offers fully equipped meeting rooms as well as printing, copying, scanning and office supplies.
  • If you are picking up a rental car when you land at the Ontario International Airport (ONT), you will need to take the free shuttle bus to the offsite rental car center. You can find the shuttle bus pickup points in front of terminals 2 and 4 at the Terminal Islands.
  • If you are flying into ONT with a pet, you will be happy to find several pet relief areas both inside and outside the terminal buildings. You will find them at terminal 2 gate 210 and terminal 4 gate 410. Otherwise, they are at the far end of each terminal building.
  • If you need to relax after your flight to Ontario, you can take advantage of the Aspire Lounge, which is open to all travelers flying into and departing from the ONT airport. You will find these in terminal 2 at gate 210 and in terminal 4 at gate 410.
  • Landed at the Ontario International Airport (ONT) and not sure where to go next? Visit one of the Travelers Aid desks. The desks are located both in terminal 2 and terminal 4 and are staffed by volunteers committed to helping you get the most out of your trip to Ontario.
  • Have you arrived at the Ontario International Airport (ONT) but your luggage has not? Head to the baggage claim counters in the arrivals area to report the incident to the representatives on duty. They will be able to track your luggage and arrange a delivery to your accommodation address once your luggage arrives in Ontario for your convenience. Just be sure to report it before you leave the airport.

Reviews of the top 5 airlines flying to Ontario

 
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.
8.0
SouthwestOverall score based on 4201 reviews
7.5Entertainment
7.0Food
8.0Comfort
8.6Crew
8.1Boarding
Airline reviews

Flight was fine. Only thing was flight was delayed nearly 2 hours. Flight was originally scheduled to depart at 7:50pm but didn't depart until 9:50pm. I got home around midnight. It was later than desired and I had to get up early next day to take kids to practice. I have noticed that last flight of day on West Coast for Southwest always tend to have delays.

6.0 GoodAnonymous, Sep 2026
Read more Southwest reviews

Flight was fine. Only thing was flight was delayed nearly 2 hours. Flight was originally scheduled to depart at 7:50pm but didn't depart until 9:50pm. I got home around midnight. It was later than desired and I had to get up early next day to take kids to practice. I have noticed that last flight of day on West Coast for Southwest always tend to have delays.

Terrible delay today. also, waited 90 minutes for baggage to unload in Seattle earlier in the week.

Seated at front bulkhead for a smidge extra leg room away from home and on flight back home. Away crew was very proactive about assuring our carryons had space close behind us (because no seat in front of us our personal items had to be in a small bin overhead). They actively required passengers place overhead luggage on its side so more items could fit in bins. Home crew made no such efforts. I had to struggle back rows to get overhead bags upon landing, no crew help then either, and some disgruntled passengers as I and others retrieved our bags. There was a system that worked pretty well. The home bound crew just didn't feel like working.

Flight left on time and was early landing. Seats not comfortable and not enough space…

It would have been better if the flight was on time

No wifi, seems to be very common with Southwest currently. Everything else was normal.

Poor customer service, no accommodation for passengers when the flight was delayed over 5 hours.

It was just okay, no frills, basic transportation with no luxury. No screens on the seats, no water or drinks on a short flight. Full flight but at least it was on time.

Our flight to Oakland was great bc the plane was new but it was delayed by 15min not bad at all. Over all it was an 8/10

The flight in it self was good. The delays looking for pilots was unexpected.

My seat was changed without my consent. It wasn’t a major deal but annoying.

The Airline Attendant found us in flight and moved us to seats in the front of economy due to the short time we would have to make our connecting flight. We really appreciated it.

DL486 could not get to the gate due to jet bridge malfunction. We moved gates. The connecting flight of LAX to MCO was not communicated with. Even though we were in the same terminal, DL482 left without about 10 of us, including a mother and her 3 children. I got to the gate at 7:34 am which is past the 7:20 am last call for a 7:35 am departure. Had they waited 5 minutes, all of us would have made it on board.

Delta has joint the nickel and diming airlines. The experience is getting worst by the day. 1,000,000 miles for a trip to Asia in Business Class where I got the same thing for just under 90,000 miles through an Asian airline. Where is Richard Anderson? Please come back!

Very bad multiple confusion and miscommunication which i ended up missing my flight.

The experience was bad. Flight was delayed to handle maintenance (understandable) but still there was some dew forming and dropping as droplets on few seats. Internet at best was allowing some browsing but at a snail pace.

Both of my flights to and from JFK experienced significant delays. Most notably, my first flight was delayed by six hours due to crew members being affected by delays on a previous flight. While I understand that disruptions can occur, Delta’s staffing and operational planning should include sufficient contingency measures to handle situations like this rather than placing the full burden of those delays on customers. Additionally, the $12 meal voucher offered as compensation was inadequate, particularly given the high cost of food and beverages at the airport. Considering the length of the delay and the substantial inconvenience caused, I believe more meaningful compensation would have been appropriate.

Comfortable seats. Nice service online. Short flight, so not a lot of time to enjoy.

The flight was done by SkyWest only WIFI no entertainment center are available on the CRJ

Delta is always late. Ruined our first day of a short vacation. Timing is important. We pay to stay on an itinerary

The food was horrible. There was no. Wifi, and it was just terrible from bangkok to d. C

My flight got cancelled. Couldn’t get my luggage. It arrived at my destination ahead of me. I didn’t get my preordered meal. Had to spend the night in the airport.

United did nit provide any updated on flight crew not bein available until boarding time started. It was bad. Itws alate night flight and there no proactive communication and iha d an important meeting that i missed due to thus

Delayed too much. 1.5 hrs in the airport and another 1 hr in the runway. Got too late in the night. There was no proper food available.

Job well done, being treated for good and helping a lot . thanks you so much till will meet against.

Even though the incoming flight was delayed by 20 minutes they managed to get us to SFO 15 minutes early.

Boarding, time to take off, in flight offerings, and staff were all great. I recommend using UA for this short flight.

The flight out of Fresno boarded 1.5 hour past scheduled and made me miss my connecting flight from SFO to SEA.

The flight was excellent. Their was no service as we boarded, the flight attendants spent about 30 minutes just taking and not really caring that the cabin was about 80 degrees and did not offered any beverage to first class passengers or any passenger. The flight from DEN to ONT is not long but not under an hour, we received one drink and bag of chips if you were lucky. I was in first class…. I did leave my hat on the plane and it only took less than five minutes for a United rep to locate and bring it to me.

Airline did not explain reasons why flight was delayed two hours. Explanations were badly needed and rarely provided. Problem seemed to clearly be the airline’s fault and not the fault of the weather or airport.

The guy sitting in front of me kept pushing hard his sit against my legs… very uncomfortable

Food was horrid. In my opinion inedible. They did offer some sorbet and one small dish of fruit. Stewards were super stingy with water, coffee, etc.

On-time, direct flight is great. Having one bathroom out of order was unfortunate.

I am absolutely furious with American. they shut the door in my face when I was trying to board the flight and kicked me off of it. They made no attempt to call my name or contact me or anything. They just said they gave my seat away. The customer service response has been atrocious. I will never fly this airline again as long as I live.

The WiFi was out gr entire flight. Had to Diane for almost 1 hour to wait for a gate to open up for plane to dock. Very bad experience.

The plane was late getting to Ontario by half an hour which makes it inconvenient when you have people waiting for you.

Smooth flight. From the early boarding and all were on board before departure time and arrived early in ONT. Great crew. Thank you!!!!

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

Everything was great except for the wifi was junk. Crew was super friendly and helpful

It was fine. I didn't love the food but it was at least a real attempt at serving a meal, unlike my earlier flight from Nashville to Dallas.

Flight was delayed by about an hour, once we arrived at LAX we had to take a shuttle to the baggage claim - it was completely disorganized. The agents at the shuttles were rude and unable to provide any information. Frontier charges extra for everything from bags to drinks - at the end it ends up being more expensive than flying the better airlines

Tiny seats, no entertainment, no amenities, delays, they charge for carry on and their allowed personal item is smaller than in other airlines.

I really didn't like anything. Paid for my checked luggage online ($79) and then was told that I would have to paid another $79 for my carry on. Was not allowed to enter the terminal until 3 hours before my flight and when I finally was allowed to check my bag and enter, my flight was delayed 3 times. When I finally landed, we were all instructed to "run off the plane" as they had to do a quick turn around to Las Vegas. Me and several of my flying companions will never fly Frontier again.

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

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

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.

Flight was cancelled and was not able to get another flight thru Frontier. Per frontier a refund was issued but I do not see a refund on my Afirm account.

The agent at check-in was strident, unwelcoming, and condescending to customers ahead of me.

Was charged 99 dollars for a bag despite agents previously telling me it would be ok. Customer service was unhelpful

I will like you ( Frontier Airlines) to fly into LAX instead of ONT because I live in LA and the subway takes me to my house in just 15 minutes

More options for your flight to Ontario