$33 Find Cheap Flights from Ontario to the United States - Compare and Save

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Cheap Flights from Ontario to the United States

Cheapest round-trip prices found by our users on KAYAK in the last 5 days
New York
New York2 stops$306
Los Angeles
Los Angeles1 stop$180
Las Vegas
Las Vegasnonstop$120
San Francisco
San Franciscononstop$75
Chicago
Chicago1 stop$201
Miami
Miami1 stop$218
Boston
Boston1 stop$251
Fort Lauderdale
Fort Lauderdale2 stops$248
Washington, D.C.
Baltimore1 stop$172
Denver
Denvernonstop$97
Seattle
Seattlenonstop$158
Atlanta
Atlanta1 stop$321
Tampa
Tampa1 stop$188
San Diego
San Diego2 stops$178
Honolulu
Honolulu2 stops$352
Philadelphia
Philadelphia1 stop$190
New York
New York2 stops$306
Los Angeles
Los Angeles1 stop$180
Las Vegas
Las Vegasnonstop$120
San Francisco
San Franciscononstop$75
Chicago
Chicago1 stop$201
Miami
Miami1 stop$218
Boston
Boston1 stop$251
Fort Lauderdale
Fort Lauderdale2 stops$248
Washington, D.C.
Baltimore1 stop$172
Denver
Denvernonstop$97
Seattle
Seattlenonstop$158
Atlanta
Atlanta1 stop$321
Tampa
Tampa1 stop$188
San Diego
San Diego2 stops$178
Honolulu
Honolulu2 stops$352
Philadelphia
Philadelphia1 stop$190
Booking Insights

Price, demand and travel trends for Ontario to the United States flights

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

Are flights from Ontario to the United States cheaper or more expensive than last year?

Fares from Ontario to the United States are running about 18% higher than they were around this time last year, averaging $376 round-trip.

What are the cheapest fares from Ontario to the United States right now?

Here are the cheapest round-trip fares from Ontario to the United States on KAYAK in the last week:

• San Francisco (SFO) from $75
• Denver Intl (DEN) from $99
• Phoenix Sky Harbor Intl (PHX) from $118
• San Jose (SJC) from $118
• Las Vegas Harry Reid Intl (LAS) from $120

What’s the cheapest month to fly from Ontario to the United States?

February is the cheapest time of year to fly, with average fares of $316. Prices are highest in June, when average flight costs increase to around $430.

When is the best time to book flights from Ontario to the United States?

Book your flights 5 weeks before your trip. KAYAK data collected over the past 12 months shows that booking in this window can save you around 30% compared to booking last-minute (within 2 weeks of departure).

Which airport in the United States is the cheapest to fly to from Ontario?

Based on KAYAK data from the past 12 months, the cheapest airports to fly into the United States are:

• Las Vegas Harry Reid Intl (LAS) from $168
• San Francisco (SFO) from $211
• Denver Intl (DEN) from $238

What’s the cheapest day to fly from Ontario to the United States?

Saturday tends to be the cheapest day to fly from Ontario to the United States, while Monday is the most expensive. Fares run about 12% higher that day, based on the past 12 months of KAYAK data.

What's the cheapest time of day to fly from Ontario to the United States?

Data from the past 12 months shows it's cheapest to fly to the United States during the evening with average prices of $311. The night is the most expensive time to fly, with average prices of $436.

Key details for Ontario to the United States flights

Low season

February

Cheapest flight

$33
Beat the crowds with an average 20% drop in travelers.
The most popular month to fly with an average 24% increase in travelers.
One-way flight from Ontario to Denver

Flights from Ontario to the United States: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from Ontario to the United States 
Verified travelerFlew with Alaska Airlines-Mar 2026
TSA security isn’t bad, sometimes gets crowded right before another flight goes out. Smaller airport but has many flight options.
AdrianaFlew with American Airlines-Apr 2026
Check on your flight status often, as things can change and you may not be notified promptly
Verified travelerFlew with United Airlines-Feb 2026
1 hr is doable if you're transferring at sfo but probably just get something to go food wise
FraxysFlew with American Airlines-Jun 2025
Bring an empty refillable water bottle/container through TSA and fill it up as soon as you pass the security check. The water station is available to the left and to the right of it.
Verified travelerFlew with Frontier-Dec 2024
Pack light and arrive earlier.. Also download the App and check your flight and check in..
LeoFlew with American Airlines-Sep 2024
Have plenty of patience for the casual travelers! They are oblivious of rules and etiquettes that slows down the process for everyone. Case in point, a guy held up the line trying to place both his personal item (should be UNDER the seat in front of you) and his carry on case horizontally. Obviously not aware of the big poster right in front of his displaying the proper way of placing his case on it's side. Slowed the whole line of people behind him. Also be mindful the agents in Ontario airport (or any smaller airports) might not be the most knowledgeable on the rules and regulations of air travel, luggage specification allowances etc. Stay patient!! Also the seats do not recline that well anymore on AA flights. So if you have back problems, be sure to bring some back supports.
Verified travelerFlew with Alaska Airlines-Oct 2024
Portland is a big airport, give yourself time.
MariFlew with American Airlines-Jan 2024
Bring a blanket it's very cold on plane

Your Ontario to the United States flight questions, answered

Find helpful answers about this route, including flight times, airports, airlines and booking tips.

  • Is now a good time to book a flight from Ontario to the United States?

    Yes. Fares from Ontario to the United States are low right now. As a rule of thumb, a round-trip under $249 (cheaper than most fares this year) is a good deal, so if you spot one at or below that, it's a good time to book.

  • How much should I budget for a flight from Ontario to the United States?

    Over the past 12 months, round-trip fares from Ontario to the United States have ranged from $249 to $515.

  • What are the main airports serving the United States?

    The United States has 50 airports. The three busiest are Seattle/Tacoma Intl (SEA) (8% of arrivals), San Francisco (SFO) (6%) and Las Vegas Harry Reid Intl (LAS) (6%).

  • What airlines fly nonstop from Ontario to the United States?

    Based on the flight schedule for the next 3 months, 7 airlines operate nonstop flights from Ontario to the United States, including:

    • Southwest
    • American Airlines
    • Delta
    • United Airlines
    • Alaska Airlines
    • Frontier

  • Where in the United States can I fly nonstop from Ontario?

    You can fly nonstop from Ontario to 20 destinations in the United States. Some of the most popular among KAYAK travelers include Seattle, Dallas, San Francisco, Las Vegas and New York.

  • Is it cheaper to fly with a layover from Ontario to the United States?

    No, nonstop flights from Ontario to the United States are typically the cheaper option, averaging $306 over the past 12 months.

  • How long is a flight from Ontario to the United States?

    Nonstop flights take 2h 15m on average. The fastest scheduled flight takes 1h, from Ontario (ONT) to Las Vegas Harry Reid Intl (LAS).

  • How often are flights from Ontario to the United States delayed and what's the average delay?

    11% of flights on this route are delayed by at least 15 minutes. The average delay is 2h 14m.

  • Which cabin classes are available on flights from Ontario to the United States?

    On flights from Ontario to the United States you can book Economy Class, Premium Economy Class, Business Class or First Class.

  • What are some popular landmarks in the United States?

    KAYAK travelers' favorite landmarks in the United States include:

    • Times Square
    • Universal Orlando Resort
    • New York City Center
    • San Antonio River Walk

  • What are the earliest and latest flights from Ontario to the United States?

    The earliest nonstop flight from Ontario to the United States departs at 5:00 am and the latest departs at 11:59 pm. Nonstop flights take about 2h 15m.

Your guide to booking Ontario to the United States flights

Get tips on when to book, when to fly and what to know before your trip.
  • If you can plan ahead, the sweet spot for booking your flight is 5 weeks before your trip. KAYAK data shows fares in this window are around 30% lower than last-minute bookings (made within 2 weeks of departure). Not ready to commit? Set a Price Alert and we'll let you know when prices change.
  • If your travel dates are flexible, book your trip for February when flights are typically cheapest and avoid June when prices are at their highest.
  • Flying on Saturday is usually the cheapest. Flights on Monday cost about 12% more on average, so being flexible with your travel dates could help you save.
  • If arriving on time matters more than price, consider flying with one of the most punctual airlines on this route: Delta, United Airlines, Alaska Airlines, American Airlines and Frontier.
  • If you're looking to save, Las Vegas Harry Reid Intl (LAS) is the cheapest airport to fly into from Ontario. If you have onward travel, don't forget to factor in the cost of your journey by train, bus or domestic flight.
  • Start your trip in New York, which is the most popular destination in the United States. From there, it's easy to continue on to other popular destinations such as Las Vegas, Chicago and Orlando.
  • Whether you're trying to save time or money, the Ontario to the United States nonstop route is usually your best option.

Reviews of the top 5 airlines serving from Ontario to the United States

 
Need help choosing which airline to fly with from Ontario to the United States? 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.
7.9
Alaska AirlinesOverall score based on 13028 reviews
8.1Boarding
7.8Comfort
7.0Food
8.5Crew
7.0Entertainment
Airline reviews

Seat didn’t recline at all- very uncomfortable after three hours

6.0 GoodAnonymous, Sep 2026
Read more Alaska Airlines reviews

Seat didn’t recline at all- very uncomfortable after three hours

The seat on row 11 was a little hard cause my butt was hurting a little bit from sitting after and hour.

The first flight was fine, great crew, but the plane was delayed 45 minutes to go to Seattle because of they were missing a ramp. That would make sense if the plane was actually at the gate. Not if we’re still waiting for a plane. After we landed we waited 30-45 minutes on the tarmac just to get off the plane. Alaska made me miss my connecting flight, wasting my time, and my money. I should honestly be reimbursed, but hey, when does the airline ever actually take accountability? Never.

Wish there were more complimentary drinks available - only had water and apple juice. Also - no snacks were provided during the flight, but we were offered some items as we exited the plane.

My daughter has anxiety and became nauseous after boarding the plane and before take off. She went to the plane bathroom and ended up having to vomit, and your staff promptly removed us from the flight. We explained that it was due to my daughter’s anxiety, and that the condition would not continue in the air, but they removed us anyway. We have flown many many times before on many different airlines and my daughter’s anxiety has resulted in nausea and sickness before takeoff, and every airline has been accommodating and professional. This is was our first time flying with your airline, and also the first time we have ever been removed from a flight. This was the worst service we have ever experienced. This was a special surprise trip we gifted to my daughter for graduating college. I had also paid to upgrade the family to first class and sit all together which we had never done before and can’t afford on a normal basis. Our removal from the flight was not only extremely embarrassing, but devastating for my daughter. My daughter and I were removed from the plane and a call was made by your staff to medical personnel, a few questions were asked of my daughter, and then she was magically cleared. All of this took mere minutes. Why this could not have been performed while we were on the plane, or why this could not have been performed off the plane and then us allowed to reboard is beyond me. My wife and youngest daughter continued on the original flight alone and were very upset and crying due to the situation, yet the staff did nothing to console or assist them. My wife states that upon arrival in Portland and as they were exiting the plane, one of the stewardesses involved said “byyyyeeeee” to them sarcastically and laughed. Myself and my oldest daughter had to wait 4 hours for an alternate flight and were sat in regular seats because our first class seat purchase could not be honored. My wife wasn’t allowed to pick up our rental car and had to wait 4 hours with our luggage until I arrived. The delay prevented us from being able to carry out planned events and ruined the first day of our trip. Upon explaining all of this to your customer service, we received no sympathy, assistance, or compensation other than your staff submitting a request for a reimbursement of my and my daughters first class upgrade cost. When checking in early for our flight back home, the luggage cost for myself and my eldest daughter was no longer discounted as it was for my wife and youngest daughter. Customer service once again could not assist me over the phone and rectify what should have been a minor adjustment. Instead they stated I would have to wait until we physically checked bags in at the airport and then ask staff to adjust the luggage cost. With everything else we had experienced, I was not going to leave that to chance and instead paid full price for the luggage ahead of time. Or experience with Alaska Airlines was a complete disaster and I am baffled at the lack of empathy and assistance from your staff. I’m not sure of what else to say other than the fact that unless we are compensated by Alaska Airlines in some form to offset the horrendous service we received, we will be relaying our experience to family and friends and on social media, and doing all we can to urge everyone to avoid utilizing your services.

I got an email 3 hours before the flight letting me know it got canceled

Boarding was easy and quick. Staff was very friendly. Service of snacks and drinks by staff was outstanding.

It was ok! Not fond of sitting in middle seat. Tried to upgrade with my Atmos card but it was a new account and they weren’t able to look up my account details.

Not bad. Due to not buying a seat, on the way back, my seat was not assigned till 2 hrs before the flight left. Got me worried I wouldn’t have a seat.

There is no entertainment on the plane. The snack is minimal. The crew was nice and professional.

I liked how it boarded fast. I do not like how the seats are just too narrow, and I’m not a big person.

Despite paying for an ‘upgraded’ seat in row 1, I had to put my luggage in the middle of the plane. Snacks were bleh and seat was small and uncomfortable and I am not large. Attendants were fine but not super helpful. Plane just seemed outdated.

Southwest has been a nightmare. Delayed flights, missed connections, systems down. Never again am I flying southwest.

had to check bag at gate when there was still overhead bin space. As usual the WIFI didn't really work.

The Southwest airline was ok. A big thank you to Kayak team (David), who worked with me on Sunday afternoon to rebook my travel from Burbank, CA, to CVG. My original flight on Sunday was delayed, so I had to cancel Sunday flight and rebook my travel to Monday. Could not have done it without help from David from Kayak team. Ante Soda GE Aerospace

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.

Red eye from San Diego. Temperature of the cabin was way too warm and the air duct flowed very little air.

I think Southwest is the number one airline that anyone can fly I have flown for the first time Frontier and what a joke and their customer service United was a very strange experience I'm only sticking to Southwest from here on out for sure

Flight was delayed, full flight and I had to change gates. Southwest flights are always late later in the day.

I liked receiving attention from aged and well experienced flight attendants. I disliked the non-gluten-free snack but I brought my own so I was OK.

Wifi is very frustrating - could not connect and therefore unable to work on the trip

Entertainment was great. Seats were good. They did not have my pre-ordered hot food product available but did comp me something cold in place of the item.

Santa Barbara is a super small and easy airport. Breezed through rental car return, breezed through Security, ordered a coffee and muffin and to my gate in less than 30 minutes. Maybe because it was a small airport we got the oldest plane. Hardly any overhead space and absolutely zero internet. Its NFL Sunday man! That hurt.

We were delay because so many bags needed to be gate checked and it was disappointing not to have outlets in the seats for such a long flight.

Excellent. I had a medical emergency on flight SNA-ORD and the attendants were very helpful.

Smooth flight, easy boarding process. Made up time in the air with initial delay due to weather pass through

awesome team work seen since on board till off plane in my destination. thanks you so much.

Flight was on time, clean, etc. Despite connecting to your wi fi I was unable to use your app to watch entertainment.

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

Seat pitch is horrible especially on the 15 hour flight. Gate crew at SFO was Outstanding. The flight crew was also great.

I was truly shocked at how poor this flight went. The crew was not friendly during the checking process. The asked for people to gate check and were rude about it. They didn't handle my luggage with care. When I got to my seat I noticed a large section of the ceiling vent area was, no joke, TAPED TOGETHER WITH CLEAR PACKING TAPE! To add insult to injury, the back rest button was disabled on my seat and all the seats I could see. The wifi, never connected for me, despite troubleshooting it for a while. I did everything from restarting my wifi/phone to forgetting the network and restarting the app. But that didn't stop the mandatory 2 ads from playing every single time. Even the bags took over 45 mins to arrive at the carousel. Everything about this flight was a flop and I am beginning to notice that some of these events are becoming a trend. Perhaps it's time I switch loyalty programs.

Little communication with passengers after sitting over 1 hour for a maintenance issue Then we had to deplane- no crew communication Poor gate information after deplaned WiFi would not connect AT ALL

Had to pay for WiFi, delayed start, and sat on the runway forever.

American was the airline that Starlux contracted for this trip. I arrived in time to make the connecting flight on American, and then the baggage-handler debacle happened. For some reason, the first class and premium economy passengers' luggage was unloaded first. Never seen this happen before. They had handlers removing the bags from the carousel for those passengers. Meanwhile, all of the economy passengers were waiting for their bags, including me. And there were a lot of bags because it was an international flight packed full. While waiting for 45 minutes, my bag didn't show. Meanwhile, an American representative showed up asking if anyone has a connecting flight to Phoenix. Of course I spoke up, and they proceeded to try to find my bag because I had to take a bus to the actual terminal to catch my flight. Which I was not informed of before I arrived. After another 15 minutes of searching, my bag was finally found with the first-class passengers' bags because they had pulled it by mistake. So I rushed to the terminal with the American representative to catch my flight, and they informed me that I missed it and could not get another flight until the next day. Of course, after being on an international flight for 18 hours, I was in no mood to hear this. Now, to be fair, there were a few American employees who tried to help me. After hearing about the missed flight, they got a supervisor to talk to. I expressed my situation to the supervisor, and she was not helpful until I asked for compensation. She agreed to get me a hotel room for the night. So I agreed, and she disappeared into her office, and I waited. And waited. And waited. And waited. While waiting, I was asked by three different employees who knew of my situation if I had been helped. I told them I was waiting for the supervisor to get the hotel room, and they said they would check. Finally, after waiting for 75 minutes, one of the employees who had asked me if I had been helped arrived with my hotel room and arranged a ride to the hotel for me. Never saw the supervisor again. It was now 8 o'clock; I arrived at 5:45! My rebooked fight was scheduled for 6:11 this morning and I have now been informed it has been delayed until 10:00. So am I happy with American? NO I'M NOT!! ;

Ontario airport boarding was very easy to park and access, is clean and TSA took 10 minutes total. Check-in was a breeze and cruise was very nice.

Good flight, seated and had a water within 5 minutes. Crew was hospitable.

The flight was on time and arrived early. The crew were friendly and helpful.

The chair cushions may need an upgrade. I have been noticing they are so worn out, thin so you’d sit in a dip 😄. Other than that, all was an enjoyable trip. Thanks AA!

VERY disappointed at the agent checking in my luggage. I know that the weight limit is 23 kg, a little over 50 pounds (50.71 pounds). Yet the agent kept repeating "50 pounds". So I said, the limit is 23 kg, and she had the audacity to say 'no, it is 22 kg!" Imagine my surprise. Was she ignorant or was she poorly trained? Not sure. The boarding process was pretty good. The speakers were loud enough so I still could hear them despite inconsiderate passengers continuing to speak while the announcements were going on. During the flight, the teenage girl sitting behind me kept pressing her feet to the back of my chair. I turned around several times, yet she did not get the hint. I did not make a fuss since I sense I had a bad streak that night with AA, so I just did the best I can to lean forward and not let that bother me.

It was wonderful upgrading to first. Plane was so cold thou. Crew was great. Wish there was a food option in first for such a long flight. Doesnt matter the time of day. Chintzy.

The seats are tiny and they don’t recline. The planes are dirty and very small. You have to pay for carry on and even the personal item that you’re allowed is smaller than with other airlines. Flights are usually delayed and there’s no screens or any amenities or entertainment.

The takeoff was the smoothest I've ever experienced on any airline and this is the first time I've flown on frontier so this was an extremely pleasant surprise!

A lady asked to stop the flight after the tunnel pulled away and we began to depart a flight that was already hours late. The attendance respectfully stopped the the plane and had the tunnel return. After the tunnel returned the passenger claimed to have changed her mind . The tunnel was then put in reverse and the passenger remained on the plane .. They should have sent the sick passenger off the plane like initially replaced. They existed a couple off the plane prior to that situation.. So.. all and all.. it was a long and flight.. .

We understand and comply with Frontier’s bag sizes. We’ve had some problems in past while having to await other passengers who do not understand the baggage restrictions or have not prepaid and that is usually our biggest concern (others delaying us) with flying Frontier. Flying OUT of ONT, however, has always been a great experience. I’ve also noted even on delayed Frontier flights very knowledgeable pilots who manage expectations well.

Long lines, rude staff, everything that's offered you have to pay for.

The last time I flew Frontier was in the 1960s when it was a “real” airline. We flew this time because of the price & schedule. As the saying goes, you get what you pay for.

I appreciated the upgrade to free cary-on bag and seat selection at no charge

Flight was delayed on the runway for 40 minutes the crew did not even offer even water to passengers to compensate for the flight delayed. The flight was delayed due to aircraft mechanical issues. Worst customer service ever

This isna terribly run airlines. If you're one minute late, they will deny your ticket. Don't waste your time or money

Flight was delayed for more than 3 hours, crew at ONT airport was rude, and when we got to DFW the airplane had an issue landing, we had to be taxied to the terminal, and the luggage was hold until the next day.

More options for your flight from Ontario to the United States

Complete your trip to the United States with a hotel stay or car rental