How popular is this Ontario to San Francisco flight route?

This flight path from Ontario to San Francisco was viewed by 162 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

How long is the flight from Ontario to San Francisco?

A quick flight from Ontario to San Francisco can take about 1h 35m. Frontier provides one of the quickest options available for as low as $87. The distance from Ontario to San Francisco is about 363 mi. All flights are typically nonstop.

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

Flying on Frontier is currently your cheapest option to San Francisco, with prices starting at $35. Additional round-trip tickets that might be worth considering are offered by Spirit Airlines and United Airlines, with the lowest prices starting at $37 and $58, respectively. You may be able to fly from Ontario to San Francisco for 70% less than the average price by searching for these airlines.

How far ahead should I book a flight from Ontario to San Francisco?

Booking 89 days in advance of your planned departure date is, on average, the best time to get cheap flights from Ontario to San Francisco. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, January is the cheapest month in which you can book a flight from Ontario to San Francisco (average of $276). Flying from Ontario to San Francisco in June is currently the most expensive (average of $358). 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 day to fly from Ontario to San Francisco?

Travelers seeking maximum savings on their Ontario to San Francisco flight should consider departing on Wednesday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

In terms of precipitation, rainfall in San Francisco ranges from 0.0 - 4.4 inches per month. January is typically the wettest month, when rainfall can reach 4.4 in. July is typically the driest time to visit San Francisco when rainfall is around 0.0 in.

If weather is an important factor for your trip to San Francisco, use this chart to help with planning. For those seeking warmer temperatures, September is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 51.8 F).

What are the cheapest flights from Ontario to San Francisco?

On average you can expect to pay $537 for a flight from Ontario to San Francisco. The cheapest flight overall is $44 while the most popular route, (Ontario - San Francisco) is currently priced at $53.

What are the most reliable airlines from Ontario to San Francisco?

Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Ontario to San Francisco on time: SkyWest Airlines (90%), Emirates (87%), Air Canada (83%).

What are the most popular airlines that fly from Ontario to San Francisco?

Before booking your flight from Ontario to San Francisco check out the most popular airlines for this route: Alaska Airlines, Delta or Frontier.

What is the cheapest day to fly round-trip from Ontario to San Francisco?

Users have found that flying from Ontario to San Francisco on a Tuesday typically leans towards higher prices. However, this doesn’t mean you still can’t find a deal. Flexibility with other aspects of your flight can still land a great price for your trip.

How far in advance should I book a flight from Ontario to San Francisco?

When searching for a good deal, it’s best to be prepared for potential fluctuations in price. We recommend booking at least 60 days in advance, which can save you up to 80% on flights from Ontario to San Francisco compared to booking the week you need them. Waiting 60 days out may not be for everyone, so we have options available for flights within the next two weeks, with the lowest price starting at $148. For sooner than that we have options available in the next 3 days from $197.

What is the cheapest month to fly from Ontario to San Francisco?

October can be a great time to fly to San Francisco from Ontario with a flight ticket averaging about $146. Cheapflights users have found deals in the month of October for as cheap as $37. The most expensive prices can be found in the month of May.

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

One of the essential ways to save on airfare from Ontario to San Francisco is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the evening could potentially save you up to 59% on airfare.

What airports do I use to fly from Ontario to San Francisco?

To fly from Ontario to San Francisco, you need to book a flight from Ontario (ONT) to San Francisco (SFO). Nonstop flights to San Francisco from Ontario take 1h 19m on average. When it comes time to book airfare, you have a few options: there are 3 outbound flights from Ontario to San Francisco offered by 6 different airlines.

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

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

How can I find direct flights from Ontario to San Francisco?

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

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

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

$51+ Cheap Flights from Ontario to San Francisco

Round-trip from	$79 (Cheapflightsfares)
One-way from	$51 (SmartFares)
Popular in	November
Cheapest in	May
Average price	$132
Good round-trip deal	$124 or less
Good one-way deal	$85 or less

Basic Economy allows a personal item only; no carry-on bags without extra fees.

Economy Plus offers extra legroom seats towards the front of the economy cabin.

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$35	Average$94	FlexibilityNo cancel fee	On-time62%
Spirit Airlines	Cheapest$37	Average$86	FlexibilityNo cancel fee	On-time65%
United Airlines	Cheapest$58	Average$200	FlexibilityNo cancel fee	On-time69%
Alaska Airlines	Cheapest$67	Average$200	FlexibilityNo cancel fee	On-time75%
Delta	Cheapest$85	Average$197	FlexibilityNo cancel fee	On-timeN/A
Southwest	Cheapest$116	Average$345	FlexibilityNo cancel fee	On-time63%

$51+ Cheap flights from Ontario to San Francisco (ONT - SFO)

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 9/28. Fares are subject to change and may not be available on all flights or dates of travel.

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Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in May or February, booked 89 days in advance, depart on a Friday or Thursday and return on a Monday

Cheap flight deals from Ontario to San Francisco

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Find flight deals from Ontario to San Francisco

Cheapest flights from Ontario to San FranciscoExplore the most affordable flight options available from Ontario to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 18, 2025.

Explore the most affordable flight options available from Ontario to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 18, 2025.

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Use the filters below to find and compare flights from Ontario to San Francisco that are best for you.

The best insider tips for Ontario to San Francisco flights

Cheapflights partnered with top experts to bring you the best recommendations for your Ontario to San Francisco trip

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Best time to book a flight from Ontario to San Francisco

Have a flexible travel schedule? Discover the best time to fly to San Francisco from Ontario with our price prediction graph.

Cheapflights Insights

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

How far ahead should I book a flight from Ontario to San Francisco?

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 August 8, 2025.

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

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

Find hourly flight availability from Ontario to San Francisco. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 18, 2025.

What is the cheapest day to fly from Ontario to San Francisco?

Use this chart to determine the cheapest time to fly round-trip from Ontario to San Francisco. Price data was last updated on August 17, 2025.

Reviews of airlines servicing San Francisco

See what other customers who have flown with Alaska Airlines, Southwest, and Delta from Ontario to San Francisco have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

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

What airports do I use to fly from Ontario to San Francisco?

How popular is this Ontario to San Francisco flight route?

How long is the flight from Ontario to San Francisco?

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

What are the most reliable airlines from Ontario to San Francisco?

What are the cheapest flights from Ontario to San Francisco?

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

How can I find direct flights from Ontario to San Francisco?

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

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

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Alternative routes for Ontario to San Francisco

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Top 6 airlines flying from Ontario to San Francisco

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Cheapest flights from Ontario to San Francisco
Explore the most affordable flight options available from Ontario to San Francisco. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 18, 2025.