Cheap flights from the United States to Ontario from $34
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from the United States to Ontario departing on 4/17. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags
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Recent round-trip flight deals from the United States to Los Angeles
These are some of the best round-trip flight deals from the United States to Los Angeles that have been recently found on momondo from popular airlines, departing in the coming months.
Recent one-way flight deals from the United States to Los Angeles
Flying one-way? These are some of the best deals recently discovered on momondo for flights from the United States to Los Angeles.
Recent last minute flight deals from the United States to Los Angeles
Planning a quick getaway from the United States to Los Angeles? These are the last-minute flight deals available now.
Recent direct flight deals from the United States to Los Angeles
If you prefer a non-stop journey, check out our latest direct flight deals to Los Angeles, so you can enjoy a seamless trip without layovers.
Frontier flights from United States to Ontario
Our best Frontier deals on United States to Ontario flight tickets
Frontier![Frontier]()
May 15![Frontier]()
May 18
SFO8:34 amSan Francisco
1h 28m
ONT10:02 amOntario
ONT8:24 amOntario
1h 38m
SFO10:02 amSan Francisco
Frontier![Frontier]()
Apr 15![Frontier]()
Apr 21
DEN10:37 pmDenver Intl
2h 22m
ONT11:59 pmOntario
ONT12:59 amOntario
2h 17m
DEN4:16 amDenver Intl
Alaska Airlines flights from United States to Ontario
Our best Alaska Airlines deals on United States to Ontario flight tickets
Alaska Airlines![Alaska Airlines]()
Apr 18![Alaska Airlines]()
Apr 20
DEN5:38 pmDenver Intl
7h 21m
1 stop
ONT11:59 pmOntario
ONT7:00 amOntario
6h 53m
1 stop
DEN2:53 pmDenver Intl
Alaska Airlines![Alaska Airlines]()
Apr 18![Alaska Airlines]()
Apr 20
DEN7:57 pmDenver Intl
15h 42m
1 stop
ONT10:39 amOntario
ONT7:00 amOntario
6h 53m
1 stop
DEN2:53 pmDenver Intl
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How to get the cheapest flight ticket from United States to Ontario
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
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Other information
What is the cheapest month to fly to Ontario?
In general, September is the cheapest month to fly from United States to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $298. If you aren’t able to travel during the month of September, then book flights to Ontario from United States during October instead. Flights to Ontario in October, while not as cheap as those in September, still average around $318.
What is the cheapest day to depart on your flight to Ontario?
The cheapest day to depart on your flight to Ontario is on a Saturday when prices can be found for as low as $380. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from United States to Ontario for around $511.
What is the cheapest time of day to depart on your flight to Ontario?
At noon is the cheapest time of day to fly from United States to Ontario when you can find flight prices for as low as $334. Flying to Ontario at noon is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying in the evening when prices are $414 on average. Flights to Ontario from United States in the evening are generally more expensive because this time of day is more convenient for travelers’ schedules.
What is the cheapest United States to Ontario flight route?
Fly from Las Vegas Harry Reid Intl to Ontario for the best United States - Ontario flight prices
How far in advance should I book a flight to Ontario?
You are more likely to see cheaper flights to Ontario from United States when booking 21 weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $403 when searching 21 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from United States for as low as $305 on momondo.
What cabin class options are available on United States to Ontario flights?
There are 4 cabin classes available to choose from on United States to Ontario flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
What is the cheapest airline that flies from United States to Ontario?
Frontier, United Airlines, and Southwest are the most popular carriers operating from United States to Ontario
What airlines fly to Ontario?
Frontier, Delta and United Airlines are the top three most popular airlines that fly to Ontario from United States according to our data. Frontier is the first choice among our users, with 30% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 13 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.
How many flights depart from United States to Ontario on average per day?
The number of flights available between United States and Ontario is 46 per day as of March 2025. The most frequent departure time is 7:00PM, with 37% of daily flights leaving in the evening.
How many flights depart from United States to Ontario on average per week?
326 flights are operational weekly from United States to Ontario as of March 2025. The most popular departure day for this route is Thu, with 19% of flights per week taking off on this day.
Cheap United States to Ontario flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from United States to Ontario
When did momondo last update prices for flights from United States to Ontario Airport?
Prices for flights from United States to Ontario Airport refresh daily.
How many operators does momondo search for flights from United States to Ontario Airport?
There are 10 operators available for flights from United States to Ontario Airport as of March 2025.
How old do you have to be to fly from United States to Ontario Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from United States to Ontario Airport.
What documentation or ID do you need to fly to Ontario Airport?
The travel and health documents required for your trip to Ontario Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Ontario Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular plane model from United States to Ontario?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from United States to Ontario is Airbus A320neo (23.18% of total bookings). The next most popular plane models are Airbus A321neo (8.58%), Boeing 737-800 Passenger/BBJ2 (winglets) (7.99%), and Boeing 737 MAX 8 (7.85%).
Best airlines flying from United States to Ontario
Compare and see reviews for airlines that fly from United States to Ontario with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $26 | Free Cancellation | Rating 6.3 7,894 reviews | |||
| PriceFrom $38 | Free Cancellation | Rating 6.0 3,293 reviews | |||
| PriceFrom $45 | Free Cancellation | Rating 8.0 9,734 reviews | |||
| PriceFrom $45 | Free Cancellation | Rating 8.0 7,944 reviews | |||
| PriceFrom $78 | Free Cancellation | Rating 8.0 155 reviews | |||
| PriceFrom $95 | Free Cancellation | Rating 7.9 2,318 reviews | |||
| PriceFrom $100 | Free Cancellation | Rating 7.4 8,623 reviews | |||
| PriceFrom $117 | Free Cancellation | Rating 8.0 4,292 reviews | |||
| PriceFrom $176 | Free Cancellation | Rating 7.3 2,953 reviews | |||
| PriceFrom $216 | Free Cancellation | Rating 7.2 10,000 reviews |
Why use momondo?
Why should I use momondo to find a flight deal from United States to Ontario?
momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from United States to Ontario. Millions of users trust and use momondo every year so you are in good hands.
Can I find flights from United States to Ontario with flexible booking policies on momondo?
All flight searches from United States to Ontario on momondo can be filtered to show those which offer flexible booking policies.
How can momondo help me find flights from United States to Ontario?
Once all potential United States to Ontario flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.
I’m not ready to book a flight from United States to Ontario right now. Can momondo alert me if prices change?
Price alerts on flights to Ontario from United States are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.