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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 2/20. 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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Find the cheapest flights from Ontario to the United States

Cheap round-trip flights

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Frontier Logo
9:43 pm - 10:53 pm
ONT
-
LAS
1h 10mnonstop
Frontier Logo
12:00 pm - 1:11 pm
LAS
-
ONT
1h 11mnonstop
$59Frontier
Fri, Feb 27 - Tue, Mar 3
Frontier Logo
10:57 am - 12:10 pm
ONT
-
LAS
1h 13mnonstop
Frontier Logo
7:55 pm - 9:03 pm
LAS
-
ONT
1h 08mnonstop
$60Frontier
Mon, Mar 9 - Wed, Mar 11
Delta Logo
5:00 pm - 12:09 am
ONT
-
SEA
7h 09m
1 stop
Delta Logo
4:40 pm - 11:49 pm
SEA
-
ONT
7h 09m
1 stop
$119Delta
Tue, Feb 17 - Mon, Feb 23
Alaska Airlines Logo
12:02 pm - 2:52 pm
ONT
-
SEA
2h 50mnonstop
Alaska Airlines Logo
8:56 pm - 11:32 pm
SEA
-
ONT
2h 36mnonstop
$128Alaska Airlines
Wed, Feb 25 - Sat, Feb 28
Alaska Airlines Logo
12:02 pm - 2:52 pm
ONT
-
SEA
2h 50mnonstop
Alaska Airlines Logo
8:30 am - 11:08 am
SEA
-
ONT
2h 38mnonstop
$129Alaska Airlines
Fri, Feb 27 - Tue, Mar 3
Southwest Logo
3:45 pm - 5:05 pm
ONT
-
PHX
1h 20mnonstop
Southwest Logo
4:40 pm - 10:40 pm
PHX
-
ONT
6h 00m
1 stop
$154Southwest
Wed, Apr 15 - Thu, Apr 16
American Airlines Logo
11:58 pm - 11:31 am
ONT
-
JFK
8h 33m
1 stop
American Airlines Logo
2:30 pm - 7:45 pm
JFK
-
ONT
8h 15m
1 stop
$237American Airlines
Sun, Feb 15 - Wed, Feb 18
American Airlines Logo
11:58 pm - 11:31 am
ONT
-
JFK
8h 33m
1 stop
American Airlines Logo
8:15 am - 6:42 pm
JFK
-
ONT
13h 27m
2 stops
$242American Airlines
Wed, Feb 18 - Sat, Feb 21
Southwest Logo
11:50 am - 4:55 pm
ONT
-
HOU
3h 05mnonstop
Southwest Logo
8:00 am - 9:30 am
HOU
-
ONT
3h 30mnonstop
$333Southwest
Sat, Apr 11 - Mon, Apr 13
Delta Logo
5:00 pm - 10:01 am
ONT
-
HOU
15h 01m
2 stops
Delta Logo
5:25 am - 12:02 pm
HOU
-
ONT
8h 37m
1 stop
$358Delta
Mon, Mar 2 - Wed, Mar 4

United Airlines flights from Ontario to United States

Our best United Airlines deals on Ontario to United States flight tickets
United Airlines
Mar 25
ONT6:37 pmOntario
6h 22m
1 stop
SEA12:59 amSeattle/Tacoma Intl
Mar 31
SEA7:12 amSeattle/Tacoma Intl
5h 02m
1 stop
ONT12:14 pmOntario
$177
United Airlines
May 8
ONT6:59 pmOntario
6h 13m
1 stop
SEA1:12 amSeattle/Tacoma Intl
May 16
SEA11:39 amSeattle/Tacoma Intl
6h 13m
1 stop
ONT5:52 pmOntario
$183
United Airlines
Mar 3
ONT6:10 amOntario
1h 33m
SFO7:43 amSan Francisco
Mar 7
SFO9:30 pmSan Francisco
1h 27m
ONT10:57 pmOntario
$192

American Airlines flights from Ontario to United States

Our best American Airlines deals on Ontario to United States flight tickets
American Airlines
Feb 21
ONT5:02 pmOntario
1h 23m
PHX7:25 pmPhoenix Sky Harbor Intl
Feb 23
PHX11:07 amPhoenix Sky Harbor Intl
1h 21m
ONT11:28 amOntario
$172
American Airlines
Feb 21
ONT9:53 amOntario
1h 20m
PHX12:13 pmPhoenix Sky Harbor Intl
Feb 23
PHX9:48 pmPhoenix Sky Harbor Intl
1h 19m
ONT10:07 pmOntario
$173
American Airlines
Feb 18
ONT5:02 pmOntario
1h 23m
PHX7:25 pmPhoenix Sky Harbor Intl
Feb 21
PHX11:15 amPhoenix Sky Harbor Intl
1h 21m
ONT11:36 amOntario
$174

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 January 24, 2026.
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

Fri 2/27

9:43 pm-10:53 pm

Nonstop1h 10m

Las Vegas Harry Reid Intl

Tue 3/3

12:00 pm-1:11 pm

Nonstop1h 11m

$59

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Mon 3/9

10:57 am-12:10 pm

Nonstop1h 13m

Las Vegas Harry Reid Intl

Wed 3/11

7:55 pm-9:03 pm

Nonstop1h 08m

$60

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 2/17

5:00 pm-12:09 am

1 stop7h 09m

Seattle/Tacoma Intl

Mon 2/23

4:40 pm-11:49 pm

1 stop7h 09m

$119

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 2/25

12:02 pm-2:52 pm

Nonstop2h 50m

Seattle/Tacoma Intl

Sat 2/28

8:56 pm-11:32 pm

Nonstop2h 36m

$128

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 2/27

12:02 pm-2:52 pm

Nonstop2h 50m

Seattle/Tacoma Intl

Tue 3/3

8:30 am-11:08 am

Nonstop2h 38m

$129

OntarioPhoenix

ONT - PHX

ONTPHX

Ontario

Wed 4/15

3:45 pm-5:05 pm

Nonstop1h 20m

Phoenix Sky Harbor Intl

Thu 4/16

4:40 pm-10:40 pm

1 stop6h 00m

$154

OntarioNew York

ONT - JFK

ONTJFK

Ontario

Sun 2/15

11:58 pm-11:31 am

1 stop8h 33m

New York John F Kennedy Intl

Wed 2/18

2:30 pm-7:45 pm

1 stop8h 15m

$237

OntarioNew York

ONT - JFK

ONTJFK

Ontario

Wed 2/18

11:58 pm-11:31 am

1 stop8h 33m

New York John F Kennedy Intl

Sat 2/21

8:15 am-6:42 pm

2 stops13h 27m

$242

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Sat 4/11

11:50 am-4:55 pm

Nonstop3h 05m

Houston Hobby

Mon 4/13

8:00 am-9:30 am

Nonstop3h 30m

$333

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Mon 3/2

5:00 pm-10:01 am

2 stops15h 01m

Houston Hobby

Wed 3/4

5:25 am-12:02 pm

1 stop8h 37m

$358

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 $280. If you aren’t able to travel during the month of January, then book flights to United States from Ontario during February instead. Flights to United States in February, while not as cheap as those in January, still average around $286.

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

According to our data, Sunday is the cheapest day to fly to United States from Ontario. The lowest ticket price found for a Sunday departure recently was $336. 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 Thursday because tickets tend to average around $389. 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 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 $335 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 $267 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

$107

Fastest flight time

1h 05m

Direct flights

Every day

Airports in United States

4,296 airports
The best one-way flight to United States from Ontario in the past 72 hours is $107. The best round-trip flight deal from Ontario to United States found on momondo in the last 72 hours is $84.
The fastest flight from Ontario to United States takes 1h 05m
Direct flights go from Ontario to United States every day.
There are 4,296 airports in United States. From Ontario there are direct flights to 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
8,370 reviews
Search Spirit Airlines flights
FrontierPriceFrom $30Free CancellationRating
5.7
3,058 reviews
Search Frontier flights
United AirlinesPriceFrom $58Free CancellationRating
7.4
9,194 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $67Free CancellationRating
8.0
11,785 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $97Free CancellationRating
8.0
4,268 reviews
Search Southwest flights
JetBluePriceFrom $155Free CancellationRating
7.2
2,895 reviews
Search JetBlue flights
DeltaPriceFrom $178Free CancellationRating
7.9
8,110 reviews
Search Delta flights
American AirlinesPriceFrom $190Free CancellationRating
7.2
11,192 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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Find better results for your trip to the United States

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