Ontario CA to San Francisco (ONT → SFO). We are tracking 30 fares on this route.
Cheapest tracked fare $19 · typical price $45 · you save about $26 (57%)
Cheapest fares we're tracking
Airline
Departs
Stops
Price
—
2026-12-05
Direct
$19
Frontier Airlines
2026-12-08
Direct
$19
Frontier Airlines
2026-12-09
Direct
$20
Frontier Airlines
2026-11-05
Direct
$23
Frontier
2026-10-19
Direct
$24
Frontier Airlines
2026-10-29
Direct
$24
Frontier
2026-11-23
Direct
$24
Frontier
2026-12-14
Direct
$24
Frontier Airlines
2026-11-12
Direct
$24
Frontier
2026-11-02
Direct
$24
Frontier
2026-12-21
Direct
$24
Frontier
2026-12-07
Direct
$24
Frontier
2026-10-26
Direct
$28
Frontier Airlines
2026-12-24
Direct
$28
Frontier Airlines
2026-11-13
Direct
$31
Frontier Airlines
2026-10-15
Direct
$32
Frontier Airlines
2026-11-09
Direct
$32
Frontier Airlines
2026-12-06
Direct
$34
Frontier
2026-11-16
Direct
$36
Frontier Airlines
2026-12-10
Direct
$36
Could you save more?
The airport you were going to fly from is often not the cheapest one. Compare every airport in a region against each other, or check whether a multi-day stopover beats the direct fare.
How cheap can flights from Ontario CA to San Francisco get?
The cheapest fare we have tracked on this route is $19, compared with a typical $45 for a trip of this distance.
Is it cheaper to fly to San Francisco from a different airport?
Often, yes. Fares out of secondary airports are frequently cheaper than the obvious hub, but they are the ones most likely to be missing from a normal search. Our reverse search compares every airport in a region against each other so the cheaper departure point is not hidden.
Could a stopover make Ontario CA to San Francisco cheaper?
Sometimes. On thin long-haul routes a two-leg trip with a multi-day stopover can beat the direct fare, and occasionally a direct fare is not sold at all. Our detour search prices those routings against the direct flight.