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$77+ 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 8/7. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SAN
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
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 June 12, 2025.

Round-trip from

$163
(FlightHub)

One-way from

$77
(Frontier)

Popular in

February

Cheapest in

January

Average price

$219
From Ontario to San Diego
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One-way flight from Ontario to San Diego
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Highest demand for flights based on searches. 0% potential increase in price ($1 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).
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Average for round-trip flights in June 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 June 12, 2025.

This FlightHub deal was found by Cheapflights users on 6/11. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/186:00 amONT - SAN
1 stop12h 10mFrontier
Tue 8/268:00 amSAN - ONT
1 stop8h 18mFrontier
Deal found 6/11$163

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 June 12, 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

Mon 8/18

6:00 am-6:10 pm

1 stop12h 10m

San Diego

Tue 8/26

8:00 am-4:18 pm

1 stop8h 18m

$163

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Wed 7/16

6:00 am-2:38 pm

1 stop8h 38m

San Diego

Wed 7/16

6:18 pm-11:59 pm

1 stop5h 41m

$497

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Sun 6/29

12:55 pm-7:29 pm

1 stop6h 34m

San Diego

Tue 7/1

6:25 am-4:13 pm

1 stop9h 48m

$627

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Thu 8/7

6:00 am-12:08 pm

1 stop6h 08m

$77

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Tue 8/19

4:00 pm-11:59 pm

1 stop7h 59m

$172

OntarioSan Diego

ONT - SAN

ONTSAN

Ontario

Mon 8/4

1:19 pm-8:16 pm

1 stop6h 57m

$177

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/12

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 June 12, 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 June 12, 2025.
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Frontier
6.0
Okay
3,295 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Overall

8.0

Food

7.1

Boarding

8.1

Comfort

7.8

Entertainment

7.1

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

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 $163. Other airlines that can offer you cheap pricing are Alaska Airlines, from $497, and American Airlines, from $627.

  • 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 $77. Alaska Airlines flights start at $172 while deals on United Airlines start at $177 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
National City
Imperial Beach
La Mesa
Alpine
Lemon Grove
Poway
Santee
Coronado

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