$43 Find Cheap Flights from Ontario to the United States

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to the United States departing on 7/19. 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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Cheap Flights from Ontario to the United States

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
New York
Newark2 stops$232
Los Angeles
Los Angeles1 stop$126
Las Vegas
Las Vegasnonstop$75
Chicago
Chicago2 stops$266
San Francisco
San Franciscononstop$111
Miami
Miami1 stop$230
Boston
Boston1 stop$197
Fort Lauderdale
Fort Lauderdale1 stop$185
Denver
Denvernonstop$101
Seattle
Seattlenonstop$131
Atlanta
Atlanta1 stop$300
Dallas
Dallas1 stop$185
Tampa
Tampa1 stop$160
Houston
Houstonnonstop$146
San Diego
San Diego1 stop$153
Honolulu
Honolulu1 stop$337
Philadelphia
Philadelphia1 stop$160
New York
Newark2 stops$232
Los Angeles
Los Angeles1 stop$126
Las Vegas
Las Vegasnonstop$75
Chicago
Chicago2 stops$266
San Francisco
San Franciscononstop$111
Miami
Miami1 stop$230
Boston
Boston1 stop$197
Fort Lauderdale
Fort Lauderdale1 stop$185
Denver
Denvernonstop$101
Seattle
Seattlenonstop$131
Atlanta
Atlanta1 stop$300
Dallas
Dallas1 stop$185
Tampa
Tampa1 stop$160
Houston
Houstonnonstop$146
San Diego
San Diego1 stop$153
Honolulu
Honolulu1 stop$337
Philadelphia
Philadelphia1 stop$160

Book Cheap Ontario to the United States Plane Tickets

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

Sun, May 10 - Tue, May 12
Frontier Logo
4:04 pm - 5:14 pm
ONT
-
LAS
1h 10mnonstop
Frontier Logo
2:32 pm - 3:44 pm
LAS
-
ONT
1h 12mnonstop
$75Frontier
Tue, Jun 9 - Wed, Jun 17
Frontier Logo
1:33 pm - 2:44 pm
ONT
-
LAS
1h 11mnonstop
Frontier Logo
6:43 pm - 7:51 pm
LAS
-
ONT
1h 08mnonstop
$76Frontier
Thu, May 28 - Fri, May 29
Frontier Logo
11:51 am - 1:02 pm
ONT
-
LAS
1h 11mnonstop
Frontier Logo
7:00 am - 8:04 am
LAS
-
ONT
1h 04mnonstop
$77Frontier
Mon, May 11 - Wed, May 13
Southwest Logo
9:55 pm - 4:50 am
ONT
-
HOU
4h 55m
1 stop
Southwest Logo
9:00 pm - 10:25 pm
HOU
-
ONT
3h 25mnonstop
$280Southwest
Tue, May 5 - Thu, May 7
American Airlines Logo
12:19 pm - 11:18 pm
ONT
-
JFK
7h 59m
1 stop
American Airlines Logo
11:00 am - 6:23 pm
JFK
-
ONT
10h 23m
2 stops
$282American Airlines
Tue, May 5 - Thu, May 7
Alaska Airlines Logo
10:39 am - 10:59 pm
ONT
-
JFK
9h 20m
1 stop
Alaska Airlines Logo
7:00 am - 2:32 pm
JFK
-
ONT
10h 32m
1 stop
$288Alaska Airlines
Sat, Sep 12 - Mon, Sep 21
American Airlines Logo
7:20 am - 8:45 pm
ONT
-
JFK
10h 25m
1 stop
American Airlines Logo
6:59 am - 11:29 am
JFK
-
ONT
7h 30m
1 stop
$291American Airlines
Fri, May 8 - Tue, May 12
Southwest Logo
1:50 pm - 6:50 pm
ONT
-
HOU
3h 00mnonstop
Southwest Logo
9:00 pm - 10:25 pm
HOU
-
ONT
3h 25mnonstop
$297Southwest
Wed, Sep 16 - Mon, Sep 21
United Airlines Logo
1:44 pm - 6:30 pm
ONT
-
HNL
7h 46m
1 stop
United Airlines Logo
9:40 pm - 12:12 pm
HNL
-
ONT
11h 32m
2 stops
$339United Airlines
Sun, Sep 13 - Thu, Sep 17
Alaska Airlines Logo
7:20 am - 10:22 am
ONT
-
HNL
6h 02mnonstop
Alaska Airlines Logo
12:43 pm - 9:20 pm
HNL
-
ONT
5h 37mnonstop
$365Alaska Airlines
Booking Insights

KAYAK's insights & trends for Ontario to the United States flights

Get data-powered insights and trends into flights from Ontario to the United States to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest Ontario to the United States flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to the United States from Ontario found in the last 72 hours was to Las Vegas, at $74 round-trip. The most popular route is from Ontario (ONT) to Dallas/Fort Worth Airport (DFW), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $231.

What is the cheapest time of day to fly to the United States?

The average price for all round-trip flights from Ontario to the United States depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to the United States is generally at night, when round-trip flights cost $366 on average. The most expensive time of day to fly to the United States is generally at night, which is peak travel time and where the average cost of a ticket is $366.

Can I save money by flying with a layover from Ontario to the United States?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $359, prices are generally cheapest when you fly direct.

What is the cheapest month to fly from Ontario to the United States?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to the United States, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ontario to the United States is January, when tickets cost $277 (return) on average. On the other hand, the most expensive months are March and December, when the average cost of round-trip tickets is $479 and $362 respectively.

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

The average price of all round-trip flights from Ontario to the United States clicked on KAYAK for each day over the last 12 months.

When flying from Ontario to United States, you should consider leaving on a Sunday and avoid Thursdays if you are looking for the best rates. For your return to Ontario, you’ll find the best rates on Fridays and the most expensive ones on Mondays.

How far in advance should I book a flight from Ontario to the United States?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to the United States, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ontario to the United States, you should book around 2 weeks before departure, which saves you about 26% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 4 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$43
Most popular time to fly and prices are also 2% lower on average.
Flight from Ontario to Las Vegas

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
ONT
-
PDX
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
ONT
-
PHX
Apr 2026
Check on your flight status often, as things can change and you may not be notified promptly
Verified travelerFlew with United Airlines
ONT
-
SFO
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
ONT
-
DFW
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
ONT
-
LAS
Dec 2024
Pack light and arrive earlier.. Also download the App and check your flight and check in..
LeoFlew with American Airlines
ONT
-
CLT
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
ONT
-
PDX
Oct 2024
Portland is a big airport, give yourself time.
MariFlew with American Airlines
ONT
-
CLT
Jan 2024
Bring a blanket it's very cold on plane

FAQs - booking United States flights

  • How does KAYAK find such low prices on flights from Ontario to the United States?

    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 Ontario to the United States.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Ontario to the United States 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 Ontario to the United States?

    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 from Ontario to the United States with an airline and back with another airline.

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

    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 from Ontario to the United States up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Top tips for finding cheap flights to the United States

  • Looking for a cheap flight? 25% of our users found tickets from Ontario to the following destinations at these prices or less: Denver $145 one-way - $239 round-trip; Dallas $161 one-way - $336 round-trip; Las Vegas $125 one-way - $178 round-trip

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.
8.0
SouthwestOverall score based on 4331 reviews
8.1Boarding
7.0Food
8.6Crew
7.5Entertainment
8.0Comfort
Airline reviews

Terrible. Even though there’s assigned seating now, they are still the slowest boarding airline of anyone.

2.0 MediocreJames, Apr 2026
LAX - MCO
Read more Southwest reviews

Terrible. Even though there’s assigned seating now, they are still the slowest boarding airline of anyone.

It was good from LAX to Phoenix, But the connection in Phoenix to Tulsa was not that great. The staff on both flights were great. The choice of free entertainment was ok nothing to brag about. The 45 min delay because of some electrical issue wasn't great from Phoenix to Tulsa. We sat there with hardly any air, The seat I had was between windows so the side of the plane pushed in on you. My being a bigger man it then made the seating area uncomfortable. The seats on the plane had no power to connect to recharge your phone or anything. I would recommend that they should look into a slot or clamp to hold your phone to enjoy while watching the entertainment choices hands-free. Also make it possible to raise the inner seat by the window be able to raise the arm rest up to make more room for larger people to set more comfortably. I would also say other then that stop price gouging the airfare or nickel and diming everything. Not fair for people having to fly for emergencies and be paying for higher prices due to the season or holidays. Your making your money either way and the cost of flying is still going to be the same regardless if there's 100 people or 200 people.

Southwest was greaat! The most expensive but the least upsetting for those we were flying to see.

Boarding was easy. The seats are small and fairly uncomfortable

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

The Southwest experience has definitely taken a dive from its early days. You can no longer deferentiate from other airlines. Air travel is too expensive. Southwest is no longer budget friendly. They have lost me as a loyal customer.

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

The seats are now more narrow. I paid for front row the seats in the front are even more narrow than before.

The flight would have been very good , if not dor the constantly screaming baby in the row behind me. Is there a way to isolate people traveling with infants? This is not the first time this has happened to me.

No headphones provided. No gf food. Only 1 beverage cart run sAN to HNL. Rarely saw crew members

I was on flight #3022 departed from San Diego, California to Medford, Oregon. I had Denise & Damaris as my flight attendants. I didn’t have much interaction with Damaris, but I did with Denise who had, this calm, cool collective voice when she spoke about the emergency exit plans before takeoff. I travel often and I’ve never met a flight attendant that can put you at ease. I felt she respects and takes pride in her position and more airlines need to adopt the integrity and respect that she has for Alaska Airlines. Debbie

They treat me well because of my one world status. Crew is attentive and professional. One of the best airlines out there.

This was my first time flying first class. I was really disappointed with the food option and lack of entertainment. I wasn’t given an option of what to eat. The breakfast was less than desirable. It was a bowl of some type of granola cereal, dried fruit, almond butter and 3 biscuits that we pretty much tasteless. There was so much fiber in that meal I was afraid I would poop myself in the flight. There was absolutely ZERO entertainment available. No tv screen to watch a movie or listen to music. No charging port for my phone. I recently flew Delta Airlines Comfort class and I had a tv screen with numerous options of music to listen to and movies to watch. Also I had a charging port for my phone. I expected more quality from first class. Please understand I am not some prima donna that feels entitled. But the price I paid for first class wasn’t worth what I experienced.

Crew were bad Didn’t help with luggage When asked for a glass of wine, I was told that they will serve later , which they didn’t to Me and didn’t serve anyone else in First class . Didn’t offer any snacks , Chips or Nuts to anyone . Flight was not crowded either. Worst Service/ or No Service !

A solidly good experience, but would’ve appreciated more communication with regards to travel delays.

Alaska is consistently the best in all categories. Excellent airlines and employees

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.

All airlines should board planes back to front, instead of catering to higher priced tickets. The boarding groups are inefficient and delay takeoff time

It was a red-eye, but the flight felt surprisingly quick. The seats were very comfortable, and that made resting much easier. I also want to thank the gentleman seated next to me, who graciously moved so my mom could sit beside me. We slept almost the entire way. The cabin crew was respectful in not disturbing us, while also being courteous and professional throughout. Thank you, United.

Boarding was again a "free for all". We were boarding group 4, and almost the entire plane was able to board before us. It's a shame that someone who follows the rules, gets the short end of the stick. Not fair.

It was perfect! I've never flown with United before, but I definitely will in the future

I had a cancelled flight because of technical issues going to my destination, and a delayed flight coming home. All told it wasn’t a total bust.

They delayed the flight from 9:00 to 11:55 At 11:45 they canceled the flight. I paid a premium price for the tickets with poor service

My flight was canceled a few hours before boarding. I was rebooked on Copa airlines and missed an important meeting .

OK, we were delayed and had to de plane and reboard.

Seats are uncomfortable. This has been a trend in the industry for decades. Trying to fit more seats on each plane to increase profits at the expense of the passenger.

Staff were good. My seat was in need of repair, but for a short flight was not problematic. Usual basic snack and drink setup that you'll find on any US carrier. Over, a decent, basic flight.

Complimentary light meal would be appreciated. But great flight crew service on all legs

The SFO Lounge crew were amazing. The bartender Faris was great. Thanks!

Was not able to do a online check-in because the American Airlines system doesn't store our visa or other passport information, allowing us to have a trouble-free check-in. We were forced to have to check-in at the counter which Changes are upgrade status given that we were not able to check in much earlier.

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

We left at 1030 am pacific from LA and supposed to land at 7 pm Eastern in NY. They made a detour, stopped in Philadelphia and didn’t land till 1130 PM Eastern!!! Worst flight experience with no pilot communication with no explanation as to what was going on. Everyone was very frustrated to say the least.

Flight boarded from Gate 159B, the farthest gate in the LAX Bradley Terminal. While the flight operated on time, the first class cabin attendant made no recognition of my being an Advantage Executive Platinum member.

The flight itself was excellent but the gate attendant made me check my carryon since she said it was an inch too big. I’ve had no problems with this carryon on recent flights on Qantas, Delta, Austrian, Southwest Airlines even though the overhead bins are the same size. there were other carryons in the bins that also looked larger than mine and there was room left in the bins for more. When I picked up my carryon from baggage claim one of the wheels had broken off.

I was in last row so that is never great bc the person in front of me leaned his seat all the way back into me.

The experience at checkin for my American Airlines flight from Sacramento to LAX was very good including the assistance I received in getting my bags checked in and boarding passes printed. Was pleasantly surprised the my bags were checked through all the way to my destination at Clark International Airport in Angeles, Philippines.

Terrible planning. And even worse gate agents. Absolutely rude behavior.

Flight was scheduled at 11:26am but they keep Delaying until midnight. They waited at airport restless.

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

The crew acted like they had never done this and kept barking passive aggressive orders at people. + the security line + the delay + sitting on the tarmac for 2 hours + none of the apps or signage updating with correct times

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

My flight was originally from SAT to MCO connecting from MCO to ORD. We got diverted to ATL and than Frontier staff there was sooo un helpful first they said they couldn’t give us any accommodation since our flight first got delayed that cancelled and now it’s 221am and I am still in ATL since they said they need to create a new flight my final destination is ORD and I have been delayed twice and cancelled. With no real help the frontier app didn’t work no email updates over all such a horrible experience

Remind customers of the need to have passport or new ID for boarding.

The flight never took off and we spent 7 hours at the airport

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.

Everything you need to know for your flight from Ontario to the United States

Information on your arrival and departure airports