Your next trip, last seen at €33
Lowest observedFrontier Airlines · Non-stop · 3 nightsWhen to fly
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The lowest fare we observed for each month. Open a month to see its days, then pick your outbound and return. A day with no price is one we will search for you.
- Lowest observed
- €33, departing 9 Dec 2026 (Last checked: 9 Oct 2026)One-way fare · Priced departure days checked in the last 14 days: 4Check live prices for this route
- Airlines seen
- Frontier Airlines, Southwest Airlines, United Airlines
- Non-stop
- Yes
About this route
Explore the fares we observed from Ontario to San Francisco. Prices move often, so pick your dates to see the latest options.
- Route distance
- 597 km
- Airlines seen
- Frontier Airlines, Southwest Airlines, United Airlines
- Seen on fares with a connection
- Southwest Airlines
Route-level information; individual journeys vary.
A clearer picture of your fare
Airport to city: straight-line distance
- Ontario International Airport (ONT) → Ontario, city gazetteer reference point (34.0500, -117.6400): ≈ 4 km.
- San Francisco International Airport (SFO) → San Francisco, city gazetteer reference point (37.7749, -122.4194): ≈ 18 km.
Approximate distances calculated from coordinates, not road distances or travel times. These airports serve the city; they are not confirmed endpoints of an offer.
Frequently asked
How much is a flight from Ontario to San Francisco?
The lowest fare we have observed is €33, found on 9 Oct 2026. Prices move, so read it as a floor rather than a quote.
When is the cheapest month to fly from Ontario to San Francisco?
In our observations December 2026 is the cheapest month so far, at €33.
Which airlines fly from Ontario to San Francisco?
These are the carriers we have seen on the route: Frontier Airlines, Southwest Airlines, United Airlines.
How many of the observed Ontario to San Francisco fares were non-stop?
26 of the 31 fares we observed were non-stop; the rest included at least one stop. That describes our observations, not every flight that operates.
How observed prices work, what "No data" means and what a fare includes: Read the flight price guide
Keep exploring
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Recently observed fares. Prices may change.
Last checked: 9 Oct 2026