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Ontario

$42+ Cheap flights from Ontario

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/27. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
Dec 13 — Dec 201
Sat 12/13
Sat 12/20
1 adult, Economy
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What to know about flights from Ontario

Discover essential information about flights departing from Ontario, including flight schedules, destinations, airlines operating at the Ontario airport, and any specific guidelines or requirements for travelers. Please note that the information is based on the most recent updates available. Data last updated November 13, 2025.

Cheapest one-way flight

$31

Cheapest round-trip flight

$51

Cheapest airline

LEVEL

Most popular destination

New York John F Kennedy Intl (JFK)

Good round-trip deal

$119 or less

Good one-way deal

$43 or less
The cheapest one-way flight from Ontario is currently to Vancouver Intl.
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The cheapest round-trip flight from Ontario is currently to Sacramento Intl.
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On average, LEVEL currently has the cheapest one-way flight from Ontario (avg. price of $638).
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New York John F Kennedy Intl (JFK) is currently the most popular flight destination from Ontario (average round-trip price of $914).
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Price to beat on a round-trip flight from Ontario.
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Price to beat on a one-way flight from Ontario.
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Find flights from Ontario

Cheapest flights from Ontario
Explore the most affordable flight options available from Ontario. Find the lowest fares based on data from user searches, with prices last updated on November 13, 2025.

This Kiwi.com deal was found by Cheapflights users on 11/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/1910:12 pmONT - SFO
Nonstop1h 40mFrontier
Sun 12/2110:31 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/11$75
This United Airlines deal was found by Cheapflights users on 11/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/46:00 amONT - SFO
Nonstop1h 24mUnited Airlines
Sat 12/69:28 pmSFO - ONT
Nonstop1h 21mUnited Airlines
Deal found 11/11$77
This Super.com deal was found by Cheapflights users on 11/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/249:59 pmONT - SFO
Nonstop1h 30mFrontier
Thu 11/2710:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/12$79
This Frontier deal was found by Cheapflights users on 11/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/249:59 pmONT - SFO
Nonstop1h 30mFrontier
Fri 11/2810:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/12$80
This Super.com deal was found by Cheapflights users on 11/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Sat 12/66:30 amSFO - ONT
1 stop7h 55mFrontier
Deal found 11/11$82
This Super.com deal was found by Cheapflights users on 11/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/42:59 pmONT - SFO
1 stop5h 04mFrontier
Mon 12/810:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/13$83
This CheapOair deal was found by Cheapflights users on 11/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/510:12 pmONT - SFO
Nonstop1h 40mFrontier
Mon 12/86:30 amSFO - ONT
1 stop7h 55mFrontier
Deal found 11/12$84
This Frontier deal was found by Cheapflights users on 11/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/112:59 pmONT - SFO
1 stop7h 04mFrontier
Mon 12/1510:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/12$85
This Frontier deal was found by Cheapflights users on 11/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/133:20 pmONT - SFO
1 stop16h 33mFrontier
Mon 12/1510:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/13$86
This CheapOair deal was found by Cheapflights users on 11/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/36:15 amONT - SFO
1 stop10h 36mFrontier
Sun 12/710:03 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/11$87
This Kiwi.com deal was found by Cheapflights users on 11/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/710:12 pmONT - SFO
Nonstop1h 40mFrontier
Fri 12/1210:20 pmSFO - ONT
Nonstop1h 28mFrontier
Deal found 11/11$88
This Super.com deal was found by Cheapflights users on 11/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/77:00 amONT - DEN
Nonstop2h 22mFrontier
Mon 1/1210:29 pmDEN - ONT
Nonstop2h 27mFrontier
Deal found 11/13$89

Find flights from Ontario within your budget

 
Find flights departing from Ontario that match your specified budget. Filter results by price range, allowing you to narrow down options and find flights that fit within your financial constraints. Please note that the search results are based on data from user searches, with fares last updated on November 13, 2025. In the last 7 days, Cheapflights users made a total of 2,558,603 searches

Fly to

San Francisco

Route

Depart

Return

Price

OntarioDenver

ONT - DEN

ONTDEN

Ontario

Sat 12/27

6:45 am-10:06 am

Nonstop2h 21m

Denver Intl

Sat 1/3

6:21 pm-11:21 pm

1 stop6h 00m

$102

OntarioDenver

ONT - DEN

ONTDEN

Ontario

Fri 12/5

6:15 am-9:04 am

1 stop25h 49m

Denver Intl

Tue 12/9

9:33 am-9:17 pm

1 stop12h 44m

$124

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 2/27

4:54 pm-12:09 am

1 stop7h 15m

Seattle/Tacoma Intl

Mon 3/2

11:15 am-1:56 pm

Nonstop2h 41m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 12/16

4:49 pm-11:25 pm

1 stop6h 36m

Seattle/Tacoma Intl

Thu 1/8

11:15 am-1:56 pm

Nonstop2h 41m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Mon 12/15

6:40 am-9:45 am

Nonstop3h 05m

Seattle/Tacoma Intl

Wed 1/7

6:05 pm-10:38 pm

1 stop4h 33m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 2/4

5:03 pm-12:09 am

1 stop7h 06m

Seattle/Tacoma Intl

Sun 2/8

7:45 pm-10:29 pm

Nonstop2h 44m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 12/18

6:00 am-12:57 pm

1 stop6h 57m

Seattle/Tacoma Intl

Wed 1/7

11:15 am-1:56 pm

Nonstop2h 41m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 12/5

5:49 pm-8:50 pm

Nonstop3h 01m

Seattle/Tacoma Intl

Mon 12/8

7:11 pm-11:58 pm

1 stop4h 47m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 12/11

1:29 pm-6:36 pm

1 stop5h 07m

Seattle/Tacoma Intl

Tue 12/16

8:05 pm-10:47 pm

Nonstop2h 42m

$129

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 12/6

12:40 pm-3:38 pm

Nonstop2h 58m

Seattle/Tacoma Intl

Sun 12/7

5:25 am-12:34 pm

1 stop7h 09m

$129

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/13

Showing 1-10 of 60 results
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Compare providers for flights from Ontario

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario in November
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
CheapOairPrice Accuracy3 starsTrust Score*3 stars
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
CheapTicketsDealPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
JustAirTicketPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: Among all the travel providers offering deals on flights from Ontario, CheapOair has been found to have the most accurate pricing. Users can find the same prices on deals on Cheapflights as CheapOair about >95% of the time. This is based on searches for flights from Ontario made on Cheapflights over the past month and is updated monthly.
  • Most trusted provider: In terms of trustworthiness, Cheapflights users rate CheapOair the highest out of those offering flight deals from Ontario. CheapOair has a user feedback rating of 3 out of 3 stars (3 being the best) and has received the most positive sentiment from Cheapflights users searching for flights from Ontario. This info is gathered from Cheapflights searches over the past month.

Ontario travel tips

Get helpful tips and advice for traveling to or from Ontario. Find recommendations for transportation, accommodations, local attractions, dining options, and other practical tips to enhance your travel experience. Please note that the travel tips are based on general knowledge and recommendations. Data last updated November 13, 2025.
  • If you are a member of the military, you can always go to the USO Lounge at Ontario International Airport (ONT), which provides free drinks, snacks, and access to high-speed Wi-Fi. It can be found directly across from Parking Lot F.
  • Parents will want to take note of the nursing rooms that are scattered throughout Ontario International Airport (ONT). These rooms provide parents with a comfortable place to tend to their children and contain amenities like padded benches, changing tables, and outlets.
  • Ontario International Airport (ONT) has several dining options to choose from, including a few fast-food restaurants, and sit-down restaurants that serve cuisines like American and Italian.

Best time to book a flight from Ontario

Have a flexible travel schedule? Discover the best time to fly from Ontario with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Travel insights for flights from Ontario

Get recent, data-driven insights about flights from Ontario including ideal travel times, pricing trends, and more.

When is the best time to book a flight from Ontario?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to San Francisco. Price data was last updated on November 7, 2025.

To ensure you get the cheapest price possible for a flight from Ontario, you should look to book at least 75 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Ontario?

Currently, December is the cheapest month in which you can book a flight from Ontario (average of $17). Flying from Ontario in July will prove the most costly (average of $51). There are multiple factors that influence the price of a flight so comparing airlines, departure airports and times can help keep costs down.

When is the cheapest time to fly from Ontario?

Use this chart to determine the cheapest time to fly round-trip from Ontario to San Francisco. Price data was last updated on November 2, 2025.

Those who are seeking the cheapest fare on flights departing from Ontario would be wise to consider leaving during Thursday evenings when prices are typically at their lowest. When considering other options, price-conscious travelers should avoid Monday at noon when fares are usually the most expensive.

Which airlines fly from Ontario?

For flights departing from Ontario check dates and pricing for the following: United Airlines, Frontier, Alaska Airlines, Southwest. These airlines depart to the following popular destinations: San Francisco.

Frontier
Frontier
From $34
American Airlines
American Airlines
From $122
Southwest
Southwest
From $97
China Airlines
China Airlines
From $602

What are popular destinations to fly to from Ontario?

Some of the most frequent flights departing from Ontario everyday are: Seattle (94 flights per day), Dallas (93 flights per day), and Atlanta (83 flights per day).

Denver Intl
Denver Intl
From $75
Las Vegas Harry Reid Intl
Las Vegas Harry Reid Intl
From $35
Taipei City Taiwan Taoyuan Intl
Taipei City Taiwan Taoyuan Intl
From $381
Dallas/Fort Worth
Dallas/Fort Worth
From $79

What is the cheapest place to fly to from Ontario?

The cheapest city to fly to from Ontario is Las Vegas Harry Reid Intl, with prices starting at $35. Explore other affordable destinations below.

Las Vegas Harry Reid Intl
Las Vegas Harry Reid Intl
From $35
San Francisco
San Francisco
From $38
San José del Cabo Los Cabos
San José del Cabo Los Cabos
From $41
Morelia
Morelia
From $43

Airline reviews for flights from Ontario

Read reviews and ratings of airlines operating flights from Ontario. Gain insights into the quality of service, in-flight amenities, customer experiences, and overall satisfaction to choose the best airline for your Ontario travel. Please note that the reviews are sourced from user searches and were last updated on November 13, 2025. In the last 7 days, Cheapflights users made a total of 2,558,603 searches.
Peruse reviews from past customers who have flown Alaska Airlines, Southwest, and United Airlines from Ontario to help guide your decision. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
11,287 reviews

Entertainment

7.0

Crew

8.5

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Alaska Airlines
8.0
Very good
11,287 reviews
Alaska Airlines
8.0
Very good
11,287 reviews

Entertainment

7.0

Crew

8.5

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Southwest
8.0
Very good
4,242 reviews
Alaska Airlines
8.0
Very good
11,287 reviews

Entertainment

7.0

Crew

8.5

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
United Airlines
7.4
Good
9,017 reviews
Alaska Airlines
8.0
Very good
11,287 reviews

Entertainment

7.0

Crew

8.5

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.
Frontier
5.8
Fair
3,109 reviews
Alaska Airlines
8.0
Very good
11,287 reviews

Entertainment

7.0

Crew

8.5

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Reviews

1 / 20
6.0
Good

Hannah,Aug 2025

SFO - SAN

Ticket said TSA pre check, but then the TSA agent said that Alaska Airlines has not actually entered the pre check information for the ticket, so I had to use regular security. During boarding, I have a disability and need to board early. The Alaska Airlines employee announced disability boarding, but then immediately announced 2 other groups to board, so I still had to fight the crowds. On the plane, the stewardess was brusk and rude. Seats were very uncomfortable, especially on lower back.

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Popular international destinations from Ontario

The most popular international flight routes departing from Ontario we’ve come across at this time.
Flights from Ontario to Guadalajara
Flights from Ontario to San José del Cabo
Flights from Ontario to San Salvador
Flights from Ontario to Morelia
Flights from Ontario to León

Related info for your journey

Access useful and relevant information related to your journey from Ontario. This can include details such as airport transportation, visa requirements, travel insurance, luggage regulations, and any other information that can ensure a smooth and hassle-free travel experience. Please note that the information is based on general guidance and may need to be verified with official sources. Data last updated November 13, 2025.

  • What are the most popular destinations to fly to from Ontario?

    This month, the top selected destinations from Ontario are Dallas/Fort Worth Airport, Denver, Guadalajara. Throughout the year, Dallas/Fort Worth Airport, Denver, Guadalajara are some of the top choices made by users flying from Ontario.

  • What is the cheapest flight from Ontario to anywhere?

    Users have flown out of Ontario for as low as $35 to Las Vegas (prices may vary depending on the airline and departure time). On average, users have booked flights for $443 to fly from Ontario.

  • What are the cheapest airlines flying from Ontario to anywhere?

    Over the past few days, we've found that Spirit Airlines, Frontier, and United Airlines have the cheapest prices from Ontario. Spirit Airlines flights from Ontario to Atlanta Hartsfield-Jackson ($24), Frontier flights from Ontario to Atlanta Hartsfield-Jackson ($34), and United Airlines flights from Ontario to Abuja ($58).

  • What is the cheapest premium economy flight from Ontario?

    Options for some of the cheapest premium economy flights from Ontario we have found on Cheapflights are as follows:
    Fly from Ontario to Las Vegas starting at $73
    Fly from Ontario to Guadalajara starting at $433
    Fly from Ontario to Portland starting at $437
    Fly from Ontario to Salt Lake City starting at $667

  • What is the cheapest first class flight from Ontario?

    If you’re looking for a cheap first-class flight from Ontario, consider Las Vegas. Prices start at $122 so you can fly first-class even on a budget.

  • What is the cheapest month to fly from Ontario?

    December is currently the cheapest month to fly from Ontario. At this moment in time July is the most expensive month. These prices are determined by multiple factors and booking in advance can help keep costs down if your schedule is not as flexible.

  • Where are the cheapest places to fly to from Ontario?

    Check out the cheapest flights from Ontario to embark to:
    Fly from Ontario to Las Vegas from $49 round trip
    Fly from Ontario to Seattle from $50 round trip
    Fly from Ontario to Denver from $57 round trip
    Fly from Ontario to Dallas from $58 round trip
    Fly from Ontario to Houston from $58 round trip

  • What parking options are available at Ontario International Airport (ONT)?

    There are a few parking options available at Ontario International Airport (ONT), including over five different lots that provide short and long-term parking. You can also opt for premium parking, which will put you closer to your terminal.

  • How can I go from downtown Ontario to Ontario International Airport (ONT)?

    If you drive from downtown Ontario to Ontario International Airport (ONT), it will take around 5 to 10 minutes. With public transportation, like bus line 61, it will take you around 30 to 35 minutes instead.

  • Is there a hotel located directly at Ontario International Airport (ONT)?

    Ontario International Airport (ONT) does not have its own on-site hotel, but there are quite a few that are just a short distance from the transportation hub. The DoubleTree by Hilton Hotel Ontario Airport has a free shuttle and is less than a 15-minute drive away.

  • Does Ontario International Airport (ONT) have any pet relief areas?

    Ontario International Airport (ONT) has pet relief areas that are both indoors and outdoors. Indoor areas can be found in Terminals 2 and 4, while outdoor areas are located at the far end of each terminal building.

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