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Find cheap flights from Ontario to the United States from $36

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 9/5. 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
0 bags
Tue 6/4
Tue 6/11

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Best United States Flight Deals

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours

New York
New York1 stop$189
Las Vegas
Las Vegasnonstop$33
Miami
Miami1 stop$178
San Francisco
San Franciscononstop$38
Chicago
Chicago1 stop$117
Boston
Boston1 stop$274
Washington, D.C.
Baltimore1 stop$188
Denver
Denvernonstop$58
Seattle
Seattlenonstop$58
Fort Lauderdale
Fort Lauderdale1 stop$306
Atlanta
Atlanta1 stop$178
Dallas
Dallasnonstop$103
Tampa
Tampa1 stop$179
Houston
Houstonnonstop$78
Honolulu
Honolulunonstop$343
San Diego
San Diego1 stop$347
Philadelphia
Philadelphia1 stop$152

Good to know

Low season

January

High season

July

Cheapest flight

$36
Best time to beat the crowds with an average 11% drop in price.
Most popular time to fly with an average 11% increase in price.
Flight from Ontario to San Francisco

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

See more FAQs

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 $85 one-way - $135 round-trip; Dallas $138 one-way - $275 round-trip; Las Vegas $35 one-way - $66 round-trip
  • Morning departure is around 12% cheaper than an evening flight, on average*.
*Average of the lowest prices shown in KAYAK’s search results for departures within the next 30 days

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
Alaska AirlinesOverall score based on 9134 reviews
8.2Boarding
7.3Food
8.6Crew
7.3Entertainment
7.9Comfort
Airline reviews

Boarded the plain and had to wait 1 hour for crew Captain to arrive from another flight

4.0 OkayRandy, May 2024SFO - SEA
Read more about Alaska Airlines reviews

Boarded the plain and had to wait 1 hour for crew Captain to arrive from another flight

The space for legs in coach is better than other Airlines you can even cross your legs!!

Comfortable seat, plenty of leg room which is so rare, overhead bin comfortably accommodated my carry-on bag. Deli box was tasty, service was good, bathrooms were clean. Uneventful flight, which I appreciate. Departed on time and landed early.

Honestly, there was not much they could do. Due to wind, the flight was delayed for several hours because we had to be diverted to San Jose where we needed to refuel before departing to Hawaii. Wish they had offered some snacks during the delays/diversion because we had to wait such a long time to finally get our food served during the flight after leaving California.

They canceled the flight 30 minutes prior to departure without any heads up.

All parts were excellent, especially staff at bag tag printing and inflight crew. Just the normal differences from past air travel could be improved but we’ve learned to accept those—cramped seats, minimal food/beverage, etc.

Better organizing of entry and exit onto the plane regarding all of the baggage people haul on. There should be a better system so those with no baggage can get in and out more quickly. The baggage haul-on situation is absurd.

Attentive crew. Best of all was the empty seat between me and my rowmate.

We had a very scary attempted landing in Palm Springs and were redirected to Ontario. It was a stressful flight.

Every thing means , crew, service, timing, boarding is very good.

There was a loud squeaky sound the whole time we were flying.

I didn’t not like that I could not select my seat and ended up with the worse seat.

The landing was bad and the hostess came two times and i was sleeping but when she served the person that nexts to me I woke up and she didn’t even asked me if I need any drink or snacks two times!!!!

Plane was late because of a mechanical malfunction and the food listed as available was not. Flight attendants seem over worked and under paid. They just done seem happy. And that can be seen in their faces.

Waited 3 hours on a plane to de-ice due to manpower issues. Waited another hour and a half once we landed because of a gate issue. Missed my connections. Created. A total of 13 hours of delay.

Great, on time departure, friendly and accommodating crew, great leg room, Smith flight

Plane was turned around due to fog half way into the flight, Delta did not properly direct passengers to stay on same flight and instead failed to properly rebook on Alaska

Like most domestic flights in the US, you are basically on your own with this airline when it comes to food, so be sure to purchase meals and drinks ahead of time or expect to arrive starving and dehydrated (like I was).

You need to be a hacker to get the (Free) WiFi

I guess they don’t serve drinks on planes anymore

I paid $380 for my one-way ticket from California to Minnesota. The fair did not include online check-in. I received instructions from their app to check in at a kiosk. At the kiosk, the boarding pass would not print until an actual person came to verify that I had a personal item and not a carry-on item, On the plane, the person next to me was drunk and allowed to continue to order alcohol. United is garbage I’d rather fly spirit.

Do not like the feeling of being in the basic economy. Everyone should feel good no matter what.

Terrible! The plane was old and you are required to connect your own device to their Wi-Fi rather than have entertainment options in the back of the seat in front of you. The Wi-Fi went out during the flight and there was only one plug for the devices every two seats. Three out of five surrounding my family did not work. The seats and spaces under them were so small I could not fit my backpack, which I’ve always brought on flights and fit before no problem. The crew were unpleasant and patronizing.

Due to one crew member not showing up to work, our flight was significantly delayed causing us to miss our connecting flight in Houston to Mississippi causing us to be delayed by more than 6 hours and missing our event all together. Very disappointing. All because ONE crew member called in sick. United did grant us a $15 meal voucher, which was a small but appreciated concession that I wasn’t able to use because I ordered my lunch and paid for it before applying the concession, and the staff said it was too late to use it. Ugh! We also had a TWO delay coming back from Mississippi, but that was on American Airlines and it was due to weather, so not their fault. Anyway, not at all impressed with United’s handling of our flight and the HUGE disappointment of missing our important family event for our 90 year old mother. All that money and all that stress and emotions for nothing. Having to wait the hour to bring an employee from LAX seemed like something that should not have happened. Why don’t you have a local back-up? Santa Ana is not a little airport in a rural area.

Crew was great and did their best to make us comfortable and captain came out at the beginning to announce why the flight was delayed, weather situation up ahead, and kept us updated throughout the flight.

United WiFi is consistently unusable (it can take 10 mins to load a single web page). If you need Wifi to do work, be prepared to lose half a day of productivity.

Awful. I got stuck next to a person carrying a dog and behind someone with a dog. People need to board these dogs downstairs. The cabin is crowded enough with your pets

Packed in like sardines, very uncomfortable. Sitting the aisle my shoulder was rammed into numerous times by rushing flight attendants. Also flight was very cold.

the head jack on my seat didn't work and the power outlet didn't work for my seat

Left 2 hours later for delayed I had to take care a kid with special need since people don’t want to move to accommodate the rest of the family. . It wasn’t bad but that made me upset that people can be that selfish.

Horrible - they lied to me about baggage & boarding, even though I specifically spoke to their agents the day before my flight about my issue. When I showed up they did not let me board and stranded me at my airport until I bought a new flight with money I did not have to spend.

The experience was great and much better than the flight going out. of course I was in first class but the service was excellent

Comfort of seats, ease of boarding. Food selection could be better

Food options were limited which is absolutely embarrassing for a Flight of this size The staff did not come around as much and I am not accustomed to such poor service from American Airlines Drinks I believe were limited to soda and water

Crew were attentive and friendly. Flight was smooth and early! I enjoyed the less crowded plane. Thank you!

We are gluten free, there were not any available complimentary gluten free options.

No meal on a cross country flight? SFO-MiA is pretty much the definition of a coast to coast flight. No meal provided. Sky high wi-fi rates too. Stop nickel and diming your customers.

The staff was unprofessional and didn’t communicate very well. The boarding process was very disheveled, potentially due to a power outage the previous day but there was no contingency plan to properly get passengers boarded the following day. Once boarded the aircraft stayed on the tarmac for over 45 minutes due to high winds. The communication was sporadic but an announcement was finally made an additional 30 minutes later that the flight was cancelled but we couldn’t get off the plane. Prior to deplaning one of the gate agents came on the plane and made an announcement for everyone to pickup their checked bags and take a card to rebook a new reservation because they didn’t have adequate staff. Flights were missed, passengers went to different airports and there was little to no assistance from AA.

Apart from the delay due to unforeseen circumstances. The leg from sjc to dfw was fine. It was the leg from dfw to orf that we encountered issues mainly due to the flight attendant crew not being friendly. We had two small children and we needed some assistance to warm up milk so the baby would sleep. The crew just didn’t get it and made things very difficult. One made a remark that the baby’s dirty diaper smell was a “gift” to the plane in a rude way. Normally I’d brush that off as a funny comment if the rest of the trip the attendants were helpful or understanding of the difficulty we faced. But that wasn’t the case. We were met with rudeness on the second leg. Whereas on the first leg the crew were so nice and helpful.

Flight From PHX to CVG was on time, very professional staff

Not good 😐 Over priced baggage fees Small hard seats No wifi or entertainment options 😕

Didn't like anything!! Horrible flight. Small seating area and hard seats. Butt was sore after 2 hour flight to Seattle No entertainment or free refreshments No wifi or USB charging receptacles to charge phone entoute like other airliners Luggage rates were 3 times as much as competitors. Difficult to navigate online luggue process to pre pay before flight Overall bad experience WILL NEVER RIDE OR RECOMMEND FRONTIER TO FRIENDS OR FAMILY MEMBERS!!! THIS IS A SHAME!! MOST MESERIBLE FLIGHT OF MY LIFE!! AND I THOUGHT SPIRIT WAS 👎 YOU GOT THEM BEAD HANDS DOWN!!

Flight was a little late taking off. Seats are too upright, no ports to charge devices, no wifi, no entertainment

Six hour delay. Poor customer service. No voucher. Bad communication. Missed important appointments.

Our flight was delayed an hour, then when we got to board our flight finally, we were waiting in our seats for take off for 45 minutes before it was communicated that there was a maintenance issue therefore we waited on the plane for over an hour while that was resolved. We did not get to Phoenix until almost 3 hours after we were originally supposed to. This was the first and last time I will be flying Frontier.

Flight was canceled with little warning. Flight was rebooked through Ontario, California and connecting flight was delayed by over three hours. Frontier is living up to their Greyhound of the skies reputation for sure.

I purchased a carry on bag online…was supposed to cost $72 but after a whole slew of bs charges, the total was over $175.00. Because of these hidden charges, I will not even consider flying Frontier ever again. It’s just not worth the hassle. I’m scratching this company off my list forever.

There were 3 leg for the trip and each leg was delayed by 90 minutes or more. The boarding process takes forever with people waiting on the jetway even though most folks do not have carry-on. The whole process is poorly managed.

They cancelled the flight then did nothing to help us rebook. It was awful - I won’t fly with them again

The process of buying the ticket and navigating all the hidden charges that Frontier throws at you was a terrible experience. The actual airport experience and flying was fine.

Book cheap flights from Ontario to the United States

Recent round-trip flight deals

6/1Sat
nonstopFrontier
1h 28mONT-SFO
6/4Tue
nonstopFrontier
1h 24mSFO-ONT
$40
5/15Wed
nonstopFrontier
1h 27mONT-SFO
5/17Fri
nonstopFrontier
1h 24mSFO-ONT
$43
6/4Tue
nonstopUnited Airlines
1h 25mONT-SFO
6/4Tue
nonstopUnited Airlines
1h 35mSFO-ONT
$163
6/4Tue
1 stopDelta
5h 06mONT-SEA
6/5Wed
1 stopDelta
6h 43mSEA-ONT
$176
5/25Sat
nonstopAmerican Airlines
3h 00mONT-DFW
6/1Sat
nonstopAmerican Airlines
3h 06mDFW-ONT
$189
6/3Mon
nonstopUnited Airlines
1h 25mONT-SFO
6/4Tue
nonstopUnited Airlines
1h 32mSFO-ONT
$189
6/20Thu
1 stopDelta
5h 27mONT-SEA
6/25Tue
1 stopDelta
4h 29mSEA-ONT
$196
6/3Mon
nonstopAlaska Airlines
2h 41mONT-SEA
6/5Wed
nonstopAlaska Airlines
2h 30mSEA-ONT
$202
5/31Fri
nonstopAlaska Airlines
2h 45mONT-SEA
5/31Fri
nonstopAlaska Airlines
2h 32mSEA-ONT
$217
10/9Wed
1 stopAmerican Airlines
7h 14mONT-SEA
10/19Sat
1 stopAmerican Airlines
7h 27mSEA-ONT
$221

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Recent one-way flight deals

9/5Thu
nonstopFrontier
1h 26mONT-SFO
$36
6/21Fri
nonstopFrontier
2h 20mONT-DEN
$36
5/28Tue
nonstopDelta
3h 00mONT-SEA
$89
6/5Wed
1 stopDelta
4h 56mONT-DEN
$98
6/4Tue
nonstopAlaska Airlines
2h 45mONT-SEA
$100
6/4Tue
1 stopAlaska Airlines
8h 07mONT-DEN
$100
10/1Tue
1 stopAmerican Airlines
4h 04mONT-DEN
$101
9/28Sat
1 stopAmerican Airlines
5h 48mONT-SFO
$113
6/4Tue
nonstopUnited Airlines
1h 25mONT-SFO
$115
5/29Wed
1 stopUnited Airlines
4h 40mONT-SEA
$119

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Last minute flights from Ontario to the United States

Last minute flight, train and bus deals

5/9Thu
nonstopFrontier
1h 27mONT-SFO
5/13Mon
nonstopFrontier
1h 29mSFO-ONT
$89
5/8Wed
nonstopFrontier
1h 27mONT-SFO
5/12Sun
nonstopFrontier
1h 29mSFO-ONT
$92
5/10Fri
multi-stopAmerican Airlines
6h 09mONT-SFO
5/13Mon
multi-stopAmerican Airlines
5h 52mSFO-ONT
$246
5/10Fri
multi-stopAmerican Airlines
6h 09mONT-SFO
5/13Mon
multi-stopAmerican Airlines
6h 14mSFO-ONT
$260
5/7Tue
multi-stopDelta
9h 09mONT-DFW
5/29Wed
multi-stopDelta
5h 53mDFW-ONT
$265
5/7Tue
multi-stopDelta
7h 54mONT-LGA
5/13Mon
multi-stopDelta
10h 47mLGA-ONT
$286
5/10Fri
multi-stopUnited Airlines
25h 52mONT-DEN
5/11Sat
nonstopUnited Airlines
2h 25mDEN-ONT
$296
5/10Fri
nonstopUnited Airlines
1h 28mONT-SFO
5/12Sun
nonstopUnited Airlines
1h 34mSFO-ONT
$324
5/7Tue
multi-stopAlaska Airlines
10h 09mONT-JFK
6/5Wed
multi-stopAlaska Airlines
11h 01mJFK-ONT
$352
5/10Fri
nonstopAlaska Airlines
2h 37mONT-SEA
5/10Fri
nonstopAlaska Airlines
2h 33mSEA-ONT
$361

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Ontario - United States Flights

Departure:

Ontario (ONT)United States

Return flight deals:

United States - Ontario

Cabin classes:

$358
$153
$296
$38

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