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Cheap flights from Ontario to the United States from $29

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to the United States departing on 1/12. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
6:15 am - 7:22 amONT-LAS
1h 07mnonstop
Frontier Logo
12:56 pm - 2:04 pmLAS-ONT
1h 08mnonstop
$51Frontier
Find Deal
Wed, Dec 3 - Thu, Dec 4
Frontier Logo
3:30 pm - 4:42 pmONT-LAS
1h 12mnonstop
Frontier Logo
1:22 pm - 2:33 pmLAS-ONT
1h 11mnonstop
$57Frontier
Find Deal
Thu, Jan 15 - Sun, Jan 18
Frontier Logo
6:15 am - 7:22 amONT-LAS
1h 07mnonstop
Frontier Logo
8:13 pm - 9:17 pmLAS-ONT
1h 04mnonstop
$58Frontier
Find Deal
Tue, Dec 9 - Tue, Dec 16
United Airlines Logo
6:00 am - 7:24 amONT-SFO
1h 24mnonstop
United Airlines Logo
9:28 pm - 10:49 pmSFO-ONT
1h 21mnonstop
$77United Airlines
Find Deal
Thu, Dec 4 - Sat, Dec 6
Delta Logo
4:49 pm - 11:25 pmONT-SEA
6h 36m1 stop
Delta Logo
7:45 pm - 10:29 pmSEA-ONT
2h 44mnonstop
$129Delta
Find Deal
Sat, Dec 13 - Mon, Jan 5
Delta Logo
4:49 pm - 11:25 pmONT-SEA
6h 36m1 stop
Delta Logo
8:30 am - 11:13 amSEA-ONT
2h 43mnonstop
$131Delta
Find Deal
Sat, Dec 6 - Sun, Dec 7
Southwest Logo
3:30 pm - 10:05 pmONT-HOU
4h 35m1 stop
Southwest Logo
5:10 am - 9:10 amHOU-ONT
6h 00m1 stop
$173Southwest
Find Deal
Fri, Dec 5 - Sun, Dec 7
American Airlines Logo
11:59 pm - 8:32 amONT-HOU
6h 33m1 stop
American Airlines Logo
8:22 pm - 11:55 pmHOU-ONT
5h 33m1 stop
$187American Airlines
Find Deal
Thu, Dec 4 - Sun, Dec 7
American Airlines Logo
9:59 am - 8:18 pmONT-HOU
8h 19m2 stops
American Airlines Logo
5:44 am - 9:54 amHOU-ONT
6h 10m1 stop
$192American Airlines
Find Deal
Sat, Dec 6 - Sun, Dec 7
Southwest Logo
11:00 am - 9:30 pmONT-LGA
7h 30m1 stop
Southwest Logo
9:50 am - 5:35 pmLGA-ONT
10h 45m1 stop
$193Southwest
Find Deal
Thu, Jan 8 - Sun, Jan 11

Frontier flights from Ontario to United States

Our best Frontier deals on Ontario to United States flight tickets
Frontier
Dec 3
ONT6:15 amOntario
1h 07m
LAS7:22 amLas Vegas Harry Reid Intl
Dec 4
LAS12:56 pmLas Vegas Harry Reid Intl
1h 08m
ONT2:04 pmOntario
$51
Find similar
Frontier
Jan 15
ONT3:30 pmOntario
1h 12m
LAS4:42 pmLas Vegas Harry Reid Intl
Jan 18
LAS1:22 pmLas Vegas Harry Reid Intl
1h 11m
ONT2:33 pmOntario
$57
Find similar
Frontier
Dec 9
ONT6:15 amOntario
1h 07m
LAS7:22 amLas Vegas Harry Reid Intl
Dec 16
LAS8:13 pmLas Vegas Harry Reid Intl
1h 04m
ONT9:17 pmOntario
$58
Find similar

United Airlines flights from Ontario to United States

Our best United Airlines deals on Ontario to United States flight tickets
United Airlines
Dec 4
ONT6:00 amOntario
1h 24m
SFO7:24 amSan Francisco
Dec 6
SFO9:28 pmSan Francisco
1h 21m
ONT10:49 pmOntario
$77
Find similar
United Airlines
Dec 5
ONT6:41 pmOntario
1h 24m
SFO8:05 pmSan Francisco
Dec 5
SFO9:28 pmSan Francisco
1h 21m
ONT10:49 pmOntario
$107
Find similar
United Airlines
Dec 4
ONT6:00 amOntario
1h 24m
SFO7:24 amSan Francisco
Dec 4
SFO10:55 amSan Francisco
1h 23m
ONT12:18 pmOntario
$132
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Ontario to United States that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated November 12, 2025.
Use the filters below to find and compare flights from Ontario to the United States that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Wed 12/3

6:15 am-7:22 am

Nonstop1h 07m

Las Vegas Harry Reid Intl

Thu 12/4

12:56 pm-2:04 pm

Nonstop1h 08m

$51

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Thu 1/15

3:30 pm-4:42 pm

Nonstop1h 12m

Las Vegas Harry Reid Intl

Sun 1/18

1:22 pm-2:33 pm

Nonstop1h 11m

$57

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Tue 12/9

6:15 am-7:22 am

Nonstop1h 07m

Las Vegas Harry Reid Intl

Tue 12/16

8:13 pm-9:17 pm

Nonstop1h 04m

$58

OntarioSan Francisco

ONT - SFO

ONTSFO

Ontario

Thu 12/4

6:00 am-7:24 am

Nonstop1h 24m

San Francisco

Sat 12/6

9:28 pm-10:49 pm

Nonstop1h 21m

$77

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 12/13

4:49 pm-11:25 pm

1 stop6h 36m

Seattle/Tacoma Intl

Mon 1/5

7:45 pm-10:29 pm

Nonstop2h 44m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 12/6

4:49 pm-11:25 pm

1 stop6h 36m

Seattle/Tacoma Intl

Sun 12/7

8:30 am-11:13 am

Nonstop2h 43m

$131

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Fri 12/5

3:30 pm-10:05 pm

1 stop4h 35m

Houston Hobby

Sun 12/7

5:10 am-9:10 am

1 stop6h 00m

$173

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Thu 12/4

11:59 pm-8:32 am

1 stop6h 33m

Houston Hobby

Sun 12/7

8:22 pm-11:55 pm

1 stop5h 33m

$187

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Sat 12/6

9:59 am-8:18 pm

2 stops8h 19m

Houston Hobby

Sun 12/7

5:44 am-9:54 am

1 stop6h 10m

$192

OntarioNew York

ONT - LGA

ONTLGA

Ontario

Thu 1/8

11:00 am-9:30 pm

1 stop7h 30m

New York LaGuardia

Sun 1/11

9:50 am-5:35 pm

1 stop10h 45m

$193

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to the United States from

How to get the cheapest flight ticket from Ontario to United States

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

What is the cheapest month to fly to United States?

In general, January is the cheapest month to fly from Ontario to United States. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $257. If you aren’t able to travel during the month of January, then book flights to United States from Ontario during September instead. Flights to United States in September, while not as cheap as those in January, still average around $313.

What is the cheapest day to depart on your flight to United States?

According to our data, Saturday is the cheapest day to fly to United States from Ontario. The lowest ticket price found for a Saturday departure recently was $335. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. If your travel schedule is flexible, try to avoid departing on a Wednesday because tickets tend to average around $387. These prices are subject to change though, so be sure to set up a Price Alert for flights to United States.

What is the cheapest time of day to depart on your flight to United States?

The cheapest time of day to fly to United States is in the afternoon when flights can be purchased for as low as $309. Try not to purchase tickets in the evening because they tend to be around $359. Of course, these prices can vary depending on the time of year and what airport you fly to.

What is the cheapest Ontario to United States flight route?

Fly from Ontario to Las Vegas Harry Reid Intl for the best Ontario - United States flight prices

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

You are more likely to see cheaper flights to United States from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to United States for around $349 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to United States from Ontario for as low as $274 on momondo.

What cabin class options are available on Ontario to United States flights?

There are 4 cabin classes available to choose from on Ontario to United States flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Ontario to United States flights?

No. A direct flight is the cheapest option for a flight between Ontario to United States.

Cheap Ontario to United States flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to United States

Best Price Found

$78

Fastest flight time

1h 05m

Direct flights

Every day

Airports in United States

1 airport
The best one-way flight to United States from Ontario in the past 72 hours is $78. The best round-trip flight deal from Ontario to United States found on momondo in the last 72 hours is $119.
The fastest flight from Ontario to United States takes 1h 05m
Direct flights go from Ontario to United States every day.
There is 1 airport near United States: Las Vegas Harry Reid Intl (LAS)
Search flight deals

  • When did momondo last update prices for flights from Ontario Airport to United States?

    Prices for flights from Ontario Airport to United States refresh daily.

  • How many operators does momondo search for flights from Ontario Airport to United States?

  • How old do you have to be to fly from Ontario Airport to United States?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Ontario Airport to United States.

  • What documentation or ID do you need to fly to United States?

    The necessary travel and health documents for your United States trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Ontario to United States?

Best airlines flying from Ontario to United States

Compare and see reviews for airlines that fly from Ontario to United States with momondo
Airline
Rating
Free Cancellation
Price
Spirit AirlinesPriceFrom $24Free CancellationRating
6.3
8,137 reviews
Search Spirit Airlines flights
FrontierPriceFrom $36Free CancellationRating
5.8
3,113 reviews
Search Frontier flights
United AirlinesPriceFrom $58Free CancellationRating
7.4
9,015 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $67Free CancellationRating
8.0
11,279 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $97Free CancellationRating
8.0
4,235 reviews
Search Southwest flights
DeltaPriceFrom $178Free CancellationRating
7.9
8,009 reviews
Search Delta flights
JetBluePriceFrom $237Free CancellationRating
7.2
2,906 reviews
Search JetBlue flights
American AirlinesPriceFrom $242Free CancellationRating
7.2
11,048 reviews
Search American Airlines flights

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to United States?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Ontario to United States for you.

Can I find flights from Ontario to United States with flexible booking policies on momondo?

Yes. All flights to United States from Ontario on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Ontario to United States?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to United States from Ontario.

I’m not ready to book a flight from Ontario to United States right now. Can momondo alert me if prices change?

If you are simply researching potential flights to United States, momondo offers a useful price alert feature which will track prices for flights to United States from Ontario and alert you when they change.

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1 adult
Fri 12/12
Fri 12/19
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