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$126+ Cheap flights from Ontario to San Diego (ONT - SAN)

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 4/4. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Apr 2 — Apr 91
Wed 4/2
Wed 4/9
1 adult, Economy
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Cheap flight deals from Ontario to San Diego

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to San Diego (SAN). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 28, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$303
(American Airlines)

One-way from

$126
(eDestinos)

Popular in

February

Cheapest in

January

Average price

$223
Provider with most accurate pricing for Ontario-San Diego flight deals.
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Provider most trusted by Cheapflights users for Ontario-San Diego flights.
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From Ontario to San Diego
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One-way flight from Ontario to San Diego
Search Deals
Highest demand for flights based on searches. 0% potential increase in price ($2 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($3 potential savings vs. average RT price).
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Average for round-trip flights in March 2025
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Find flight deals from Ontario to San Diego

Cheapest flights from Ontario to San Diego
Explore the most affordable flight options available from Ontario to San Diego. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 28, 2025.

This American Airlines deal was found by Cheapflights users on 3/26. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1712:50 pmONT - SAN
1 stop8h 47mAmerican Airlines
Mon 4/214:30 pmSAN - ONT
1 stop19h 29mAmerican Airlines
Deal found 3/26$303
This Alaska Airlines deal was found by Cheapflights users on 3/27. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/2311:46 amONT - SAN
1 stop8h 58mAlaska Airlines
Wed 4/309:00 amSAN - ONT
1 stop6h 32mAlaska Airlines
Deal found 3/27$343
This United Airlines deal was found by Cheapflights users on 3/27. 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.
Fri 4/111:20 pmONT - SAN
1 stop10h 58mUnited Airlines
Tue 4/1510:00 amSAN - ONT
1 stop7h 51mUnited Airlines
Deal found 3/27$403
This United deal was found by Cheapflights users on 3/27. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/127:05 amONT - SAN
1 stop4h 51mMultiple Airlines
Sat 4/122:00 pmSAN - ONT
1 stop9h 59mMultiple Airlines
Deal found 3/27$764

Cheapflights Fare Finder

Customize your flight search to find flights from Ontario to San Diego 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, Cheapflights users made 2,558,603 searches. Data last updated March 28, 2025.
Use the filters below to find and compare flights from Ontario to San Diego that are best for you.

Fly from

Ontario

Fly to

San Diego

Route

Depart

Return

Price

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 4/17

12:50 pm-9:37 pm

1 stop8h 47m

San Diego

Mon 4/21

4:30 pm-11:59 am

1 stop19h 29m

$303

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 4/23

11:46 am-8:44 pm

1 stop8h 58m

San Diego

Wed 4/30

9:00 am-3:32 pm

1 stop6h 32m

$343

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Fri 4/11

1:20 pm-12:18 am

1 stop10h 58m

San Diego

Tue 4/15

10:00 am-5:51 pm

1 stop7h 51m

$403

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sat 4/12

7:05 am-11:56 am

1 stop4h 51m

San Diego

Sat 4/12

2:00 pm-11:59 pm

1 stop9h 59m

$764

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Fri 4/4

9:41 pm-7:16 pm

1 stop21h 35m

$126

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 4/23

12:50 pm-9:37 pm

1 stop8h 47m

$157

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 5/7

11:46 am-6:59 pm

1 stop7h 13m

$172

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Mon 5/5

6:00 am-2:34 pm

1 stop8h 34m

$180

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 6/12

1:36 pm-12:15 am

1 stop10h 39m

$217

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 4/8

1:20 pm-5:44 pm

1 stop4h 24m

$337

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/28

Compare providers for flights from Ontario to San Diego

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 to San Diego in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*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: When it comes to deals on Ontario-San Diego flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-San Diego flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-San Diego flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-San Diego flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-San Diego flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Ontario to San Diego

Have a flexible travel schedule? Discover the best time to fly to San Diego 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.

Cheapflights Insights

Everything you need to know about your flight from Ontario to San Diego

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

Currently, August is the cheapest month in which you can book a flight from Ontario to San Diego (average of $286). Flying from Ontario to San Diego in March is currently the most expensive (average of $366). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from ONT to SAN?

Find hourly flight availability from Ontario to San Diego. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 28, 2025.

It’s typically best to fly out from Ontario to San Diego in the morning. Doing so could potentially save you 28% on the flight price compared to flying at noon, which is usually more expensive.

Rainfall in San Diego by month

Plan your trip to San Diego by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in San Diego ranges from 0.0 - 2.3 inches per month. February is typically the wettest month, when rainfall can reach 2.3 in. July is typically the driest time to visit San Diego when rainfall is around 0.0 in.

Temperature in San Diego by month

Plan your trip to San Diego by taking into account the average temperature totals by month.

If weather is an important factor for your trip to San Diego, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 71.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 57.2 F).

Reviews of airlines servicing San Diego

Get insights into the airlines that provide service to San Diego. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to San Diego. Reviews last updated March 28, 2025.
Alaska Airlines
8.0
Very good
9,798 reviews

Entertainment

7.1

Overall

8.0

Food

7.1

Comfort

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot
Alaska Airlines
8.0
Very good
9,798 reviews
Alaska Airlines
8.0
Very good
9,798 reviews

Entertainment

7.1

Overall

8.0

Food

7.1

Comfort

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot
Hawaiian Airlines
7.9
Good
2,336 reviews
Alaska Airlines
8.0
Very good
9,798 reviews

Entertainment

7.1

Overall

8.0

Food

7.1

Comfort

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot
United Airlines
7.4
Good
8,603 reviews
Alaska Airlines
8.0
Very good
9,798 reviews

Entertainment

7.1

Overall

8.0

Food

7.1

Comfort

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
9,798 reviews

Entertainment

7.1

Overall

8.0

Food

7.1

Comfort

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot
Frontier
6.0
Okay
3,271 reviews
Alaska Airlines
8.0
Very good
9,798 reviews

Entertainment

7.1

Overall

8.0

Food

7.1

Comfort

7.9

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Seleste,Dec 2024

FAT - SAN

The attention and efficiency of the staff and the good handling of the pilot

Related info for your journey

Find useful and relevant information for your journey from Ontario to San Diego. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What are the cheapest airlines flying from Ontario to San Diego round-trip?

    Cheapflights users have booked flights from Ontario to San Diego round-trip from $303. Other airlines that can offer you cheap pricing are Alaska Airlines, from $343, and United Airlines, from $403.

  • What are the cheapest airlines to fly from Ontario to San Diego one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $126. American Airlines flights start at $157 while deals on Alaska Airlines start at $172 one-way.

  • Can I find deals for flights from Ontario to San Diego that include hotel bookings?

    Yes. In addition to deals on Ontario to San Diego flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to San Diego?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to San Diego.

  • Can I find deals for business class flights from Ontario to San Diego?

    Yes. Cheapflights offers flight deals from Ontario to San Diego by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, August is the cheapest month in which you can book a flight from Ontario to San Diego (average of $286). Flying from Ontario to San Diego in March is currently the most expensive (average of $366). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Ontario?

Book flights to Ontario if you plan to visit one of these locations
El Cajon
Chula Vista
Lemon Grove
National City
Imperial Beach
La Mesa
Alpine
Poway
Santee
Coronado
Borrego Springs

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