Cheap flights from Ontario to San Francisco from £31
This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 6/11. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — SFO
21 Oct — 28 Oct1
Return
1 adult
Economy
Return
1 adult, Economy, 0 bags
Cheapflights Tip: The best prices from Ontario to San Francisco are usually found in October or August, booked 73 days in advance, depart on a Tuesday or Monday and return on a Monday
Cheap flight deals from Ontario to San Francisco
Enter your travel dates to find the best prices.
Cheapest
Best
Direct
Last-minute
One-way
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 21 September 2026.
Thu 15/1013:38 -
1 stop5h 26m
Mon 19/1018:02 -
Nonstop1h 38m
Deal found 19/9£62
Sat 17/1013:52 -
Nonstop1h 29m
Sat 17/1021:25 -
Nonstop1h 26m
Deal found 21/9£87
Tue 3/1106:00 -
Nonstop1h 30m
Tue 10/1116:35 -
Nonstop1h 26m
Deal found 17/9£89
Sat 17/1008:03 -
Nonstop1h 27m
Sun 18/1021:25 -
Nonstop1h 26m
Deal found 18/9£103
Sun 18/1006:07 -
Nonstop1h 27m
Tue 20/1016:10 -
Nonstop1h 31m
Deal found 17/9£104
Tue 3/1117:00 -
1 stop4h 20m
Tue 10/1107:00 -
1 stop4h 55m
Deal found 17/9£105
Fri 9/1006:00 -
Nonstop1h 27m
Tue 13/1008:40 -
Nonstop1h 43m
Deal found 18/9£107
Tue 3/1115:50 -
1 stop4h 40m
Wed 4/1107:00 -
2 stops9h 10m
Deal found 17/9£109
Wed 9/1205:45 -
2 stops6h 35m
Wed 9/1213:30 -
1 stop7h 05m
Deal found 17/9£113
Mon 26/1018:55 -
1 stop5h 45m
Wed 28/1005:20 -
1 stop4h 25m
Deal found 16/9£114
Sat 10/1011:10 -
Nonstop1h 33m
Sat 10/1016:15 -
Nonstop1h 31m
Deal found 17/9£115
Best flights from Ontario to San Francisco
Discover carefully curated flight deals from Ontario to San Francisco that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 21 September 2026.
Tue 20/1017:00 -
1 stop5h 50m
Wed 28/1015:50 -
1 stop6h 15m
Deal found 17/9£105
Tue 20/1016:03 -
Nonstop1h 47m
Wed 28/1018:50 -
Nonstop1h 25m
Deal found 17/9£155
Mon 9/1116:00 -
2 stops6h 45m
Thu 12/1105:15 -
1 stop5h 35m
Deal found 20/9£116
Tue 3/1105:55 -
2 stops6h 55m
Tue 10/1107:00 -
1 stop4h 55m
Deal found 18/9£116
Mon 26/1013:35 -
Nonstop1h 30m
Wed 28/1018:50 -
Nonstop1h 25m
Deal found 16/9£156
Sat 7/1109:25 -
Nonstop1h 30m
Sun 8/1121:20 -
Nonstop1h 28m
Deal found 18/9£170
Fri 16/1006:00 -
Nonstop1h 27m
Sat 17/1021:25 -
Nonstop1h 26m
Deal found 20/9£175
Mon 1/207:40 -
2 stops7h 10m
Wed 3/206:45 -
2 stops7h 35m
Deal found 17/9£192
Sat 17/1013:52 -
Nonstop1h 29m
Tue 20/1016:10 -
Nonstop1h 31m
Deal found 16/9£195
Tue 20/1009:15 -
2 stops7h 55m
Sun 25/1006:15 -
1 stop6h 00m
Deal found 17/9£197
Sat 10/1005:45 -
2 stops6h 30m
Tue 13/1005:20 -
2 stops10h 20m
Deal found 17/9£226
Fri 26/218:45 -
2 stops5h 30m
Sat 27/206:45 -
1 stop3h 15m
Deal found 20/9£237
Direct flights from Ontario to San Francisco
Explore direct flight options from Ontario to San Francisco based on user searches, and compare prices and availability for your desired travel dates. Data last updated 21 September 2026.
Sat 17/1013:52 -
Nonstop1h 29m
Sat 17/1021:25 -
Nonstop1h 26m
Deal found 21/9£87
Tue 3/1113:35 -
Nonstop1h 30m
Wed 4/1118:50 -
Nonstop1h 25m
Deal found 17/9£89
Sat 17/1008:03 -
Nonstop1h 27m
Sun 18/1021:25 -
Nonstop1h 26m
Deal found 18/9£103
Sun 18/1006:07 -
Nonstop1h 27m
Tue 20/1008:40 -
Nonstop1h 43m
Deal found 17/9£104
Fri 12/213:33 -
Nonstop1h 29m
Mon 15/221:30 -
Nonstop1h 36m
Deal found 20/9£107
Sat 10/1011:10 -
Nonstop1h 33m
Sat 10/1016:15 -
Nonstop1h 31m
Deal found 17/9£115
Wed 14/1013:52 -
Nonstop1h 29m
Sun 18/1021:25 -
Nonstop1h 26m
Deal found 20/9£118
Wed 14/1013:52 -
Nonstop1h 29m
Fri 16/1019:00 -
Nonstop1h 31m
Deal found 16/9£119
Fri 16/1013:52 -
Nonstop1h 29m
Fri 23/1021:25 -
Nonstop1h 26m
Deal found 18/9£123
Wed 7/1013:52 -
Nonstop1h 29m
Wed 7/1021:25 -
Nonstop1h 26m
Deal found 17/9£127
Thu 22/1012:01 -
Nonstop1h 31m
Mon 26/1018:02 -
Nonstop1h 38m
Deal found 16/9£130
Fri 9/1006:00 -
Nonstop1h 27m
Sat 10/1008:40 -
Nonstop1h 43m
Deal found 16/9£134
Last-minute flights from Ontario to San Francisco
Discover last-minute flight deals from Ontario to San Francisco. Data last updated 21 September 2026 and is based on user searches.
Fri 9/1006:00 -
Nonstop1h 27m
Tue 13/1008:40 -
Nonstop1h 43m
Deal found 18/9£107
Sat 10/1011:10 -
Nonstop1h 33m
Sat 10/1016:15 -
Nonstop1h 31m
Deal found 17/9£115
Thu 15/1013:38 -
1 stop5h 26m
Mon 19/1018:02 -
Nonstop1h 38m
Deal found 19/9£62
Thu 15/1013:30 -
2 stops5h 15m
Sat 17/1005:00 -
1 stop3h 45m
Deal found 18/9£116
Sat 17/1013:52 -
Nonstop1h 29m
Sat 17/1021:25 -
Nonstop1h 26m
Deal found 21/9£87
Sat 17/1008:03 -
Nonstop1h 27m
Sun 18/1021:25 -
Nonstop1h 26m
Deal found 18/9£103
Sun 18/1006:07 -
Nonstop1h 27m
Tue 20/1016:10 -
Nonstop1h 31m
Deal found 17/9£104
Tue 20/1017:00 -
1 stop5h 50m
Wed 28/1015:50 -
1 stop6h 15m
Deal found 17/9£105
Mon 26/1018:55 -
1 stop5h 45m
Wed 28/1006:55 -
1 stop3h 50m
Deal found 20/9£113
One-way flights from Ontario to San Francisco
Search for one-way flight options from Ontario to San Francisco. Find affordable one-way fares based on user searches. Data last updated 21 September 2026.
Fri 6/1112:01 -
Nonstop1h 35m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 19/9£31
Mon 26/1012:01 -
Nonstop1h 31m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 19/9£38
Sat 10/1013:52 -
Nonstop1h 29m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 18/9£44
Tue 20/1011:26 -
1 stop6h 59m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 21/9£45
Fri 23/1012:01 -
Nonstop1h 31m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 21/9£46
Mon 19/1008:00 -
1 stop24h 13m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 21/9£49
Tue 10/1115:20 -
1 stop6h 05m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 17/9£53
Sat 31/1013:45 -
1 stop4h 00m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 19/9£57
Sat 24/1011:10 -
Nonstop1h 33m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 17/9£59
Thu 10/1205:45 -
2 stops6h 35m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 20/9£60
Sat 24/1006:15 -
1 stop18h 00m
Wed 31/1200:00 -
Nonstop0h 00m
Deal found 21/9£61
Find flight deals from Ontario to San Francisco
Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to San Francisco (SFO). 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 21 September 2026.
Customise your flight search to find flights from Ontario to San Francisco 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 7,457,451 searches. Data last updated 21 September 2026.
Use the filters below to find and compare flights from Ontario to San Francisco that are best for you.
Fly from
Fly to
Route
Depart
Return
Price
Cheapest return flight
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Thu 17/12
06:00-07:33
Nonstop1h 33m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£44
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Mon 14/12
12:50-20:10
2 stops7h 20m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£60
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Tue 20/10
13:52-15:21
Nonstop1h 29m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£78
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Sat 24/10
13:52-15:21
Nonstop1h 29m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£78
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Tue 27/10
09:25-10:55
Nonstop1h 30m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£78
Fastest return journey
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Wed 21/10
08:03-09:30
Nonstop1h 27m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£78
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Sat 5/12
11:20-12:50
Nonstop1h 30m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£85
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Mon 26/10
13:35-15:05
Nonstop1h 30m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£100
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Tue 29/9
15:35-21:40
1 stop6h 05m
San Francisco
Wed 31/12
00:00-00:00
Nonstop0h 00m
£104
OntarioSan Francisco
ONT Ontario - SFO San Francisco
ONTSFO
Ontario
Tue 20/10
17:00-22:50
1 stop5h 50m
San Francisco
Wed 28/10
15:50-22:05
1 stop6h 15m
£105
Flights are sorted by cheapest return flights first.
Deals found on 18/9
Showing 1-10 of 24 resultsSorted by cheapest first
1
2
3
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.
ONT-SFO
Estimated return 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 Francisco
Prices
Airlines
How far ahead should I book a flight from Ontario to San Francisco?
The best time to book flights from Ontario to San Francisco is 72 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
What is the cheapest month to book a flight from Ontario to San Francisco?
Currently, October is the cheapest month in which you can book a flight from Ontario to San Francisco (average of £104). Flying from Ontario to San Francisco in February is currently the most expensive (average of £228). 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 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 21 September 2026.
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 midday tend to be the most expensive. A flight in the morning could potentially save you up to 93% on airfare.
How much does it cost for a return flight from Ontario to San Francisco?
Airfare is below average for this route at the moment.
Ontario to San Francisco flights typically cost between £86 and £169 in October.The cheapest return price found within the last 5 days was £62 on Frontier (15 Oct–19 Oct).
Weekly flight availability from Ontario to San Francisco
Explore weekly flight availability from Ontario to San Francisco. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated 21 September 2026.
The most flights from ONT to SFO are scheduled on a Sunday (12 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (2 on average).
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.
How popular is this Ontario to San Francisco flight route?
This flight path from Ontario to San Francisco was viewed by 20 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?
Departing from Ontario to San Francisco will take you 1h 29m. The distance from Ontario to San Francisco is about 363 mi. Both multi-stop and direct flights can be found to your destination and back.
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: Emirates (75%), Air Canada (62%), United Airlines (62%).
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 holiday 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.
What is the cheapest month to book a flight from Ontario to San Francisco?
Currently, October is the cheapest month in which you can book a flight from Ontario to San Francisco (average of £104). Flying from Ontario to San Francisco in February is currently the most expensive (average of £228). 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.
Explore flights to San Francisco departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on 21 September 2026.
Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.
How does Cheapflights help users find flights from Ontario to San Francisco?
When you search for this flight from Ontario to San Francisco, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.
Why should you use Cheapflights to find cheap flight tickets from Ontario to San Francisco?
Cheapflights simply makes it quick and affordable to book flights from Ontario to San Francisco by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.
Can Cheapflights find flights from Ontario to San Francisco with no change fees?
Cheapflights does show flights with no change fees to all users. To see these options for flights from Ontario to San Francisco, users can toggle the no change fees filter when performing a flight search.
Can Cheapflights notify me if prices for flights from Ontario to San Francisco become cheaper?
Of course! You can now track prices for flights from Ontario to San Francisco and get an alert from Cheapflights when they change. Have a valid email address ready and click the bell icon next to the flight deals above to set up your price alerts.
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.
We value your privacy
Cheapflights and its partners wish to use cookies or similar technologies to store and/or access information on and about your device and process personal data such as your IP address, device identifiers etc., in order to improve your experience on the site, to analyse navigation, to offer and measure personalised advertising, and to facilitate sharing on social networks. We also allow the use of third-party cookies (including those from our advertising partners) on our sites.
By clicking 'Accept', you consent to your data being processed by 0 vendors on this web site for the purposes described in this notice. You can review the vendors and their individual processing purposes on the .
To review individual processing purposes and cookie categories, please click ’Select individual purposes’. You can review your choices and withdraw your consent at any time by clicking the ’Privacy Preferences’ link in the page side navigation.