What is the cheapest airline that flies from Ontario to United States?

Frontier, Southwest, and Delta are the most popular carriers operating from Ontario to United States

How many flights depart from Ontario to United States on average per day?

As of December 2025, there are 40 flights per day flying from Ontario to United States. The most common time of day flights depart is 7:00AM, with 48% of flights taking off at noon.

What airlines fly to United States?

Frontier, Spirit Airlines and American Airlines are the top three most popular airlines that fly to United States from Ontario according to our data. Frontier is the first choice among our users, with 33% of people opting to fly with this airline when traveling to United States. Keep in mind that there are 12 different airlines that fly to United States on a routine basis, so you have a few additional options to choose from.

How many flights depart from Ontario to United States on average per week?

As of December 2025, there are 280 flights per week flying from Ontario to United States. The most common day of the week flights depart is Thu, with 26% of flights taking off on this day.

What day of the week experiences the fewest flight delays on this route?

Saturday is statistically the day of the week which experiences the fewest number of delays on this flight route. Thursday has historically seen more delays on average compared to the rest of the week.

How often are flights from Ontario to the United States delayed?

Historically, on average around 12% of flights between Ontario and United States have experienced a delay on any given week. The average delay length over the past 12 months has been 125 minutes.

What is the most punctual flight time for Ontario to the United States flights?

Generally, flights departing in the morning tend to experience fewer delays. Flights in the evening have, in the past, seen delays more frequently in comparison.

Which airline has the best punctuality record on Ontario to the United States flights?

According to our data, Delta have had the least number of delays on this route over the last 12 months; with about 4% of their flights experiencing any sort of delay.

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?

As of December 2025, there are 9 operators available to choose from 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.

$35 Cheap Flights from Ontario to the United States in 2025/26

1 adult

0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from Ontario to the United States

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

4:04 pm - 5:11 pm

ONT

LAS

1h 07mnonstop

4:45 pm - 5:54 pm

LAS

ONT

1h 09mnonstop

$57Frontier

Tue, Jan 6 - Tue, Jan 13

7:52 am - 9:00 am

ONT

LAS

1h 08mnonstop

2:00 pm - 3:09 pm

LAS

ONT

1h 09mnonstop

$58Frontier

Tue, Jan 6 - Tue, Jan 6

7:52 am - 9:00 am

ONT

LAS

1h 08mnonstop

8:45 am - 9:50 am

LAS

ONT

1h 05mnonstop

$59Frontier

Tue, Jan 6 - Wed, Jan 7

3:30 pm - 6:35 pm

ONT

SEA

3h 05mnonstop

5:00 am - 12:16 pm

SEA

ONT

7h 16m1 stop

$129Delta

Wed, Jan 21 - Sat, Jan 24

11:53 am - 2:44 pm

ONT

SEA

2h 51mnonstop

8:15 am - 10:59 am

SEA

ONT

2h 44mnonstop

$138Alaska Airlines

Tue, Jan 20 - Sun, Jan 25

5:07 pm - 11:22 pm

ONT

SEA

6h 15m1 stop

5:25 am - 12:16 pm

SEA

ONT

6h 51m1 stop

$139Delta

Fri, Jan 9 - Sun, Jan 11

5:15 am - 10:15 am

ONT

HOU

3h 00mnonstop

3:35 pm - 5:10 pm

HOU

ONT

3h 35mnonstop

$333Southwest

Thu, Jan 29 - Thu, Jan 29

6:00 am - 12:45 pm

ONT

HOU

4h 45m1 stop

9:30 pm - 11:05 pm

HOU

ONT

3h 35mnonstop

$339Southwest

Wed, Mar 18 - Wed, Mar 18

7:10 am - 3:50 pm

ONT

HOU

6h 40m1 stop

12:17 pm - 4:24 pm

HOU

ONT

6h 07m1 stop

$353American Airlines

Sat, Feb 14 - Tue, Feb 17

6:00 am - 6:06 pm

ONT

HOU

10h 06m1 stop

6:36 pm - 10:48 pm

HOU

ONT

6h 12m1 stop

$359American Airlines

Sun, Jan 18 - Mon, Jan 26

Delta flights from Ontario to United States

Our best Delta deals on Ontario to United States flight tickets

Delta

Jan 21

ONT5:10 pmOntario

6h 59m

1 stop

SEA12:09 amSeattle/Tacoma Intl

Jan 25

SEA11:15 amSeattle/Tacoma Intl

2h 41m

ONT1:56 pmOntario

$129

Find similar

Delta

Feb 26

ONT6:00 amOntario

6h 33m

1 stop

SEA12:33 pmSeattle/Tacoma Intl

Feb 28

SEA5:30 amSeattle/Tacoma Intl

6h 37m

1 stop

ONT12:07 pmOntario

$139

Find similar

Delta

Jan 18

ONT7:30 amOntario

3h 06m

SEA10:36 amSeattle/Tacoma Intl

Jan 22

SEA8:07 pmSeattle/Tacoma Intl

2h 44m

ONT10:51 pmOntario

$159

Find similar

Frontier flights from Ontario to United States

Our best Frontier deals on Ontario to United States flight tickets

Frontier

Jan 6

ONT4:04 pmOntario

1h 07m

LAS5:11 pmLas Vegas Harry Reid Intl

Jan 13

LAS4:45 pmLas Vegas Harry Reid Intl

1h 09m

ONT5:54 pmOntario

$57

Find similar

Frontier

Jan 6

ONT7:52 amOntario

1h 08m

LAS9:00 amLas Vegas Harry Reid Intl

Jan 6

LAS2:00 pmLas Vegas Harry Reid Intl

1h 09m

ONT3:09 pmOntario

$58

Find similar

Frontier

Jan 6

ONT7:52 amOntario

1h 08m

LAS9:00 amLas Vegas Harry Reid Intl

Jan 7

LAS8:45 amLas Vegas Harry Reid Intl

1h 05m

ONT9:50 amOntario

$59

Find similar

Fly from

Fly to

Route

Depart

Return

Price

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Tue 1/6

4:04 pm-5:11 pm

Nonstop1h 07m

Las Vegas Harry Reid Intl

Tue 1/13

4:45 pm-5:54 pm

Nonstop1h 09m

$57

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Tue 1/6

7:52 am-9:00 am

Nonstop1h 08m

Las Vegas Harry Reid Intl

Tue 1/6

2:00 pm-3:09 pm

Nonstop1h 09m

$58

OntarioLas Vegas

ONT - LAS

ONTLAS

Ontario

Tue 1/6

7:52 am-9:00 am

Nonstop1h 08m

Las Vegas Harry Reid Intl

Wed 1/7

8:45 am-9:50 am

Nonstop1h 05m

$59

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 1/21

3:30 pm-6:35 pm

Nonstop3h 05m

Seattle/Tacoma Intl

Sat 1/24

5:00 am-12:16 pm

1 stop7h 16m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 1/20

11:53 am-2:44 pm

Nonstop2h 51m

Seattle/Tacoma Intl

Sun 1/25

8:15 am-10:59 am

Nonstop2h 44m

$138

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 1/9

5:07 pm-11:22 pm

1 stop6h 15m

Seattle/Tacoma Intl

Sun 1/11

5:25 am-12:16 pm

1 stop6h 51m

$139

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Thu 1/29

5:15 am-10:15 am

Nonstop3h 00m

Houston Hobby

Thu 1/29

3:35 pm-5:10 pm

Nonstop3h 35m

$333

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Wed 3/18

6:00 am-12:45 pm

1 stop4h 45m

Houston Hobby

Wed 3/18

9:30 pm-11:05 pm

Nonstop3h 35m

$339

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Sat 2/14

7:10 am-3:50 pm

1 stop6h 40m

Houston Hobby

Tue 2/17

12:17 pm-4:24 pm

1 stop6h 07m

$353

OntarioHouston

ONT - HOU

ONTHOU

Ontario

Sun 1/18

6:00 am-6:06 pm

1 stop10h 06m

Houston Hobby

Mon 1/26

6:36 pm-10:48 pm

1 stop6h 12m

$359

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

Delays

Other information

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 $258. 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 $292.

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 $346 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 $279 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	$85
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 $85. The best round-trip flight deal from Ontario to United States found on momondo in the last 72 hours is $118.

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?
As of December 2025, there are 9 operators available to choose from 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?
Based on momondo bookings for flights between Ontario and United States, the leading plane model is Airbus A320neo, making up 13.09% of the total bookings. Other popular models include Boeing 737 MAX 8 with 11.65%, Airbus A321neo with 9.41%, and Boeing 737-800 Passenger/BBJ2 (winglets) with 9.37%.

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 Airlines	PriceFrom $24	Free Cancellation	Rating 6.3 8,190 reviews	Search Spirit Airlines flights
Frontier	PriceFrom $34	Free Cancellation	Rating 5.8 3,082 reviews	Search Frontier flights
United Airlines	PriceFrom $58	Free Cancellation	Rating 7.4 9,092 reviews	Search United Airlines flights
Alaska Airlines	PriceFrom $67	Free Cancellation	Rating 8.0 11,474 reviews	Search Alaska Airlines flights
Southwest	PriceFrom $97	Free Cancellation	Rating 7.9 4,249 reviews	Search Southwest flights
Delta	PriceFrom $153	Free Cancellation	Rating 7.9 8,006 reviews	Search Delta flights
American Airlines	PriceFrom $183	Free Cancellation	Rating 7.2 11,053 reviews	Search American Airlines flights
JetBlue	PriceFrom $223	Free Cancellation	Rating 7.2 2,895 reviews	Search JetBlue 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.

An easier way to manage your United States trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Start using Trips

Find my bookings

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

1 adult

Sat 1/17

Sat 1/24

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States

Popular cities in the United States

Flights to New Yorkfrom $45

Flights to Los Angelesfrom $48

Flights to Miamifrom $49

Flights to Chicagofrom $58

Flights to Orlandofrom $40

Flights to San Franciscofrom $58

Flights to Las Vegasfrom $49

Flights to Washington, D.C.from $57

Flights to Bostonfrom $51

Flights to Atlantafrom $46

Flights to Dallasfrom $57

Flights to Seattlefrom $58

Cheap flights from Ontario to the United States from $35

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 1/8. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from Ontario to the United States

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Cheap direct flights

Delta flights from Ontario to United States

Our best Delta deals on Ontario to United States flight tickets

Frontier flights from Ontario to United States

Our best Frontier deals on Ontario to United States flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Ontario to the United States that are best for you.

See travel insights to the United States from

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

What is the cheapest month to fly to United States?

What is the cheapest day to depart on your flight 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?

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.

What is the cheapest airline that flies from Ontario to United States?

Frontier, Southwest, and Delta are the most popular carriers operating from Ontario to United States

What airlines fly to United States?

How often are flights from Ontario to the United States delayed?

Historically, on average around 12% of flights between Ontario and United States have experienced a delay on any given week. The average delay length over the past 12 months has been 125 minutes.

What is the most punctual flight time for Ontario to the United States flights?

Generally, flights departing in the morning tend to experience fewer delays. Flights in the evening have, in the past, seen delays more frequently in comparison.

What day of the week experiences the fewest flight delays on this route?

Saturday is statistically the day of the week which experiences the fewest number of delays on this flight route. Thursday has historically seen more delays on average compared to the rest of the week.

Which airline has the best punctuality record on Ontario to the United States flights?

According to our data, Delta have had the least number of delays on this route over the last 12 months; with about 4% of their flights experiencing any sort of delay.

How many flights depart from Ontario to United States on average per day?

As of December 2025, there are 40 flights per day flying from Ontario to United States. The most common time of day flights depart is 7:00AM, with 48% of flights taking off at noon.

How many flights depart from Ontario to United States on average per week?

As of December 2025, there are 280 flights per week flying from Ontario to United States. The most common day of the week flights depart is Thu, with 26% of flights taking off on this day.

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

Direct flights

Airports in United States

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

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?

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

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

Why use momondo?

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

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

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

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

An easier way to manage your United States trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Popular cities in the United States

Popular flights according to clicks in the last 7 days on momondo