HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$77+ Cheap flights from San Diego to Ontario (SAN - ONT)

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 8/18. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — ONT
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from San Diego to Ontario with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from San Diego to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from San Diego (SAN) to Ontario (ONT). 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

$153
(Frontier)

One-way from

$77
(Frontier)

Popular in

April

Cheapest in

February

Average price

$545
From San Diego to Ontario
Search Deals
One-way flight from San Diego to Ontario
Search Deals
Highest demand for flights based on searches. 14% potential increase in price ($82 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($20 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2025
Search Deals

Find flight deals from San Diego to Ontario

Cheapest flights from San Diego to Ontario
Explore the most affordable flight options available from San Diego to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 12, 2025.

This Frontier 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/28:00 amSAN - ONT
1 stop8h 18mFrontier
Thu 9/117:35 pmONT - SAN
1 stop3h 29mFrontier
Deal found 6/11$153
This United Airlines deal was found by Cheapflights users on 6/10. 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.
Wed 9/178:00 amSAN - ONT
1 stop9h 37mUnited Airlines
Sun 9/211:42 pmONT - SAN
1 stop18h 13mUnited Airlines
Deal found 6/10$354
This KAYAK deal was found by Cheapflights users on 6/10. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/1712:48 pmSAN - ONT
1 stop3h 25mAmerican Airlines
Thu 6/1912:55 pmONT - SAN
1 stop6h 34mAmerican Airlines
Deal found 6/10$859

Cheapflights Fare Finder

Customize your flight search to find flights from San Diego 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, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
Use the filters below to find and compare flights from San Diego to Ontario that are best for you.

Fly from

San Diego

Fly to

Ontario

Route

Depart

Return

Price

San DiegoOntario

SAN - ONT

SANONT

San Diego

Tue 9/2

8:00 am-4:18 pm

1 stop8h 18m

Ontario

Thu 9/11

7:35 pm-11:04 pm

1 stop3h 29m

$153

San DiegoOntario

SAN - ONT

SANONT

San Diego

Tue 6/17

12:48 pm-4:13 pm

1 stop3h 25m

Ontario

Thu 6/19

12:55 pm-7:29 pm

1 stop6h 34m

$859

San DiegoOntario

SAN - ONT

SANONT

San Diego

Mon 8/18

8:13 am-11:53 am

1 stop3h 40m

$77

San DiegoOntario

SAN - ONT

SANONT

San Diego

Tue 8/12

4:20 pm-11:32 am

1 stop19h 12m

$171

San DiegoOntario

SAN - ONT

SANONT

San Diego

Wed 8/6

6:20 am-10:52 pm

1 stop16h 32m

$177

San DiegoOntario

SAN - ONT

SANONT

San Diego

Fri 8/29

8:22 pm-9:26 am

1 stop13h 04m

$187

San DiegoOntario

SAN - ONT

SANONT

San Diego

Wed 6/18

8:10 am-6:38 pm

1 stop10h 28m

$251

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/12

Best time to book a flight from San Diego to Ontario

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

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

Currently, August is the cheapest month in which you can book a flight from San Diego to Ontario (average of $246). Flying from San Diego to Ontario in March is currently the most expensive (average of $328). 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 SAN to ONT?

Find hourly flight availability from San Diego to Ontario. 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 optimal to fly from San Diego to Ontario in the morning. By choosing this option you can save up to 13% on the cost of your flight, compared to a flight at noon.

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Ontario, 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 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated June 12, 2025.
Alaska Airlines
8.0
Very good
10,000 reviews

Food

7.1

Entertainment

7.1

Boarding

8.1

Overall

8.0

Comfort

7.8

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

Food

7.1

Entertainment

7.1

Boarding

8.1

Overall

8.0

Comfort

7.8

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

Food

7.1

Entertainment

7.1

Boarding

8.1

Overall

8.0

Comfort

7.8

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

Food

7.1

Entertainment

7.1

Boarding

8.1

Overall

8.0

Comfort

7.8

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

Food

7.1

Entertainment

7.1

Boarding

8.1

Overall

8.0

Comfort

7.8

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 San Diego to Ontario. 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 San Diego to Ontario round-trip?

    Our cheapest airline available from San Diego to Ontario is Frontier. Our recent data shows that you can find tickets from as low as $153 on this airline. An additional option worth looking into is American Airlines, starting at $859. Frontier is priced at 67% lower than the current average price of a flight leaving 3 months from now.

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

    One-way options have recently been found by users for as low as $77 on Frontier. Other airlines that offer cheap prices include American Airlines from $171 and United Airlines from $177 one-way.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from San Diego to Ontario 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 San Diego to Ontario?

    Currently, August is the cheapest month in which you can book a flight from San Diego to Ontario (average of $246). Flying from San Diego to Ontario in March is currently the most expensive (average of $328). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for San Diego to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to San Francisco flights
San Francisco to Las Vegas flights
Los Angeles to Las Vegas flights
San Jose to Los Angeles flights
San Francisco to Los Angeles flights
Los Angeles to San Jose flights
Oakland to Santa Ana flights
Santa Ana to Las Vegas flights
Oakland to Las Vegas flights
Oakland to Los Angeles flights
Burbank to Las Vegas flights
Los Angeles to Oakland flights
San Jose to Las Vegas flights
Ontario to San Francisco flights
San Francisco to Santa Ana flights
Santa Ana to Oakland flights
San Francisco to Ontario flights
Santa Ana to San Francisco flights
San Jose to San Diego flights
Burbank to Oakland flights
San Francisco to San Diego flights
Los Angeles to Sacramento flights
Ontario to Las Vegas flights
Sacramento to Los Angeles flights
Oakland to Burbank flights
San Jose to Santa Ana flights
Burbank to San Francisco flights
Oakland to San Diego flights
Sacramento to Las Vegas flights
Los Angeles to Reno flights
Las Vegas to Los Angeles flights
Sacramento to San Diego flights
Santa Ana to San Jose flights
San Jose to Ontario flights
San Diego to San Francisco flights
San Diego to Las Vegas flights
San Francisco to Burbank flights
Ontario to San Jose flights
Stockton to Las Vegas flights
San Diego to San Jose flights
Burbank to Sacramento flights
Las Vegas to San Francisco flights
Santa Ana to Sacramento flights
San Diego to Sacramento flights
Sacramento to Santa Ana flights
San Francisco to Palm Springs flights
Ontario to Sacramento flights
Burbank to San Jose flights
Fresno to Las Vegas flights
Sacramento to Ontario flights

Top airline flying from San Diego to Ontario

Discover the top airline that operate flights from San Diego to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapest$281Average$412FlexibilityNo cancel feeOn-time75%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.