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Cheap flights from the United States to Los Angeles from $39

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 Los Angeles departing on 1/6. 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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Find the cheapest flights from the United States to Los Angeles

Recent round-trip flight deals from the United States to Los Angeles

Enter your travel dates to find the best prices.
Frontier Logo
1:34 pm - 3:07 pm
DEN
-
ONT
2h 33mnonstop
Frontier Logo
6:20 am - 9:40 am
ONT
-
DEN
2h 20mnonstop
$71Frontier
Tue, Jan 27 - Fri, Jan 30
Frontier Logo
9:45 pm - 11:24 pm
DEN
-
ONT
2h 39mnonstop
Frontier Logo
6:20 am - 9:40 am
ONT
-
DEN
2h 20mnonstop
$72Frontier
Sat, Jan 24 - Sun, Feb 8
Frontier Logo
1:34 pm - 3:07 pm
DEN
-
ONT
2h 33mnonstop
Frontier Logo
6:20 am - 9:40 am
ONT
-
DEN
2h 20mnonstop
$73Frontier
Wed, Jan 21 - Sun, Jan 25
Delta Logo
7:00 pm - 11:58 pm
SEA
-
ONT
4h 58m1 stop
Delta Logo
3:30 pm - 6:35 pm
ONT
-
SEA
3h 05mnonstop
$129Delta
Fri, Jan 23 - Sat, Jan 24
Delta Logo
5:25 am - 12:16 pm
SEA
-
ONT
6h 51m1 stop
Delta Logo
7:30 am - 10:36 am
ONT
-
SEA
3h 06mnonstop
$130Delta
Sat, Jan 17 - Sun, Jan 18
Alaska Airlines Logo
8:05 pm - 10:44 pm
SEA
-
ONT
2h 39mnonstop
Alaska Airlines Logo
6:14 am - 9:09 am
ONT
-
SEA
2h 55mnonstop
$138Alaska Airlines
Tue, Feb 24 - Sat, Feb 28
American Airlines Logo
7:00 am - 2:18 pm
LGA
-
ONT
10h 18m1 stop
American Airlines Logo
11:59 pm - 11:29 am
ONT
-
LGA
8h 30m1 stop
$236American Airlines
Tue, Feb 10 - Fri, Feb 13
Southwest Logo
3:35 pm - 5:10 pm
HOU
-
ONT
3h 35mnonstop
Southwest Logo
5:15 am - 10:15 am
ONT
-
HOU
3h 00mnonstop
$333Southwest
Wed, Jan 21 - Tue, Feb 3
Southwest Logo
8:05 am - 12:30 pm
HOU
-
ONT
6h 25m1 stop
Southwest Logo
2:45 pm - 7:40 pm
ONT
-
HOU
2h 55mnonstop
$339Southwest
Thu, Mar 26 - Mon, Mar 30
American Airlines Logo
12:17 pm - 10:49 pm
HOU
-
ONT
12h 32m1 stop
American Airlines Logo
6:10 am - 3:50 pm
ONT
-
HOU
7h 40m1 stop
$346American Airlines
Wed, Feb 18 - Tue, Mar 3

Frontier flights from United States to Ontario

Our best Frontier deals on United States to Ontario flight tickets
Frontier
Jan 27
DEN1:34 pmDenver Intl
2h 33m
ONT3:07 pmOntario
Jan 30
ONT6:20 amOntario
2h 20m
DEN9:40 amDenver Intl
$71
Find similar
Frontier
Jan 24
DEN9:45 pmDenver Intl
2h 39m
ONT11:24 pmOntario
Feb 8
ONT6:20 amOntario
2h 20m
DEN9:40 amDenver Intl
$72
Find similar
Frontier
Jan 21
DEN1:34 pmDenver Intl
2h 33m
ONT3:07 pmOntario
Jan 25
ONT6:20 amOntario
2h 20m
DEN9:40 amDenver Intl
$73
Find similar

Delta flights from United States to Ontario

Our best Delta deals on United States to Ontario flight tickets
Delta
Jan 23
SEA7:00 pmSeattle/Tacoma Intl
4h 58m
1 stop
ONT11:58 pmOntario
Jan 25
ONT7:30 amOntario
3h 06m
SEA10:36 amSeattle/Tacoma Intl
$129
Find similar
Delta
Jan 17
SEA5:25 amSeattle/Tacoma Intl
6h 51m
1 stop
ONT12:16 pmOntario
Jan 18
ONT7:30 amOntario
3h 06m
SEA10:36 amSeattle/Tacoma Intl
$130
Find similar
Delta
Jan 17
SEA5:25 amSeattle/Tacoma Intl
6h 51m
1 stop
ONT12:16 pmOntario
Jan 18
ONT7:30 amOntario
3h 06m
SEA10:36 amSeattle/Tacoma Intl
$131
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from United States to Ontario 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 December 14, 2025.
Use the filters below to find and compare flights from the United States to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 1/27

1:34 pm-3:07 pm

Nonstop2h 33m

Ontario

Fri 1/30

6:20 am-9:40 am

Nonstop2h 20m

$71

DenverOntario

DEN - ONT

DENONT

Denver Intl

Sat 1/24

9:45 pm-11:24 pm

Nonstop2h 39m

Ontario

Sun 2/8

6:20 am-9:40 am

Nonstop2h 20m

$72

DenverOntario

DEN - ONT

DENONT

Denver Intl

Wed 1/21

1:34 pm-3:07 pm

Nonstop2h 33m

Ontario

Sun 1/25

6:20 am-9:40 am

Nonstop2h 20m

$73

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Fri 1/23

7:00 pm-11:58 pm

1 stop4h 58m

Ontario

Sat 1/24

3:30 pm-6:35 pm

Nonstop3h 05m

$129

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Sat 1/17

5:25 am-12:16 pm

1 stop6h 51m

Ontario

Sun 1/18

7:30 am-10:36 am

Nonstop3h 06m

$130

SeattleOntario

SEA - ONT

SEAONT

Seattle/Tacoma Intl

Tue 2/24

8:05 pm-10:44 pm

Nonstop2h 39m

Ontario

Sat 2/28

6:14 am-9:09 am

Nonstop2h 55m

$138

New YorkOntario

LGA - ONT

LGAONT

New York LaGuardia

Tue 2/10

7:00 am-2:18 pm

1 stop10h 18m

Ontario

Fri 2/13

11:59 pm-11:29 am

1 stop8h 30m

$236

HoustonOntario

HOU - ONT

HOUONT

Houston Hobby

Wed 1/21

3:35 pm-5:10 pm

Nonstop3h 35m

Ontario

Tue 2/3

5:15 am-10:15 am

Nonstop3h 00m

$333

HoustonOntario

HOU - ONT

HOUONT

Houston Hobby

Thu 3/26

8:05 am-12:30 pm

1 stop6h 25m

Ontario

Mon 3/30

2:45 pm-7:40 pm

Nonstop2h 55m

$339

HoustonOntario

HOU - ONT

HOUONT

Houston Hobby

Wed 2/18

12:17 pm-10:49 pm

1 stop12h 32m

Ontario

Tue 3/3

6:10 am-3:50 pm

1 stop7h 40m

$346

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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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

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 $287. 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 $287.

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 Friday when prices can be found for as low as $302. This is often the case because there is less demand to fly during this day of the week. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from United States to Ontario for around $387.

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 morning when prices are $362 on average. Flights to Ontario from United States in the morning 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 San Francisco 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 weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $354 when searching 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 $275 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.

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

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

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

Best Price Found

$77

Fastest flight time

1h 00m

Direct flights

Every day

Airports in Ontario

1 airport
The best one-way flight to Ontario from United States in the past 72 hours is $77. The best round-trip flight deal from United States to Ontario found on momondo in the last 72 hours is $76.
The fastest flight from United States to Ontario takes 1h 00m
Direct flights go from United States to Ontario every day.
There is 1 airport in Ontario. From United States there are direct flights to Ontario (ONT).
Search flight deals

  • 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?

  • 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?

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
FrontierPriceFrom $38Free CancellationRating
5.8
3,081 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $44Free CancellationRating
6.3
8,185 reviews
Search Spirit Airlines flights
United AirlinesPriceFrom $58Free CancellationRating
7.4
9,092 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $59Free CancellationRating
8.0
11,450 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $84Free CancellationRating
7.9
4,250 reviews
Search Southwest flights
DeltaPriceFrom $108Free CancellationRating
7.9
8,007 reviews
Search Delta flights
American AirlinesPriceFrom $163Free CancellationRating
7.2
11,052 reviews
Search American Airlines flights
JetBluePriceFrom $250Free CancellationRating
7.2
2,895 reviews
Search JetBlue flights

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.

An easier way to manage your Ontario trip

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