San Francisco to Ontario CA (SFO → ONT). We are tracking 21 fares on this route.
Cheapest tracked fare $17 · typical price $56 · you save about $39 (70%)
Cheapest fares we're tracking
Airline
Departs
Stops
Price
—
2026-12-12
Direct
$17
Frontier Airlines
2026-12-08
Direct
$19
—
2026-12-01
Direct
$20
Frontier Airlines
2026-11-16
Direct
$22
Frontier Airlines
2026-11-12
Direct
$24
Frontier Airlines
2026-11-09
Direct
$24
Frontier Airlines
2026-10-22
Direct
$24
—
2026-12-07
Direct
$26
Frontier Airlines
2026-11-13
Direct
$28
Frontier Airlines
2026-10-23
Direct
$30
Frontier Airlines
2026-10-19
Direct
$30
Frontier Airlines
2026-10-29
Direct
$31
Frontier Airlines
2026-12-04
Direct
$33
Frontier Airlines
2026-12-06
Direct
$33
Frontier Airlines
2026-12-11
Direct
$33
Frontier Airlines
2026-11-05
Direct
$35
—
2026-12-05
Direct
$37
Frontier Airlines
2026-11-22
1 stop
$38
Frontier Airlines
2026-10-18
Direct
$50
Frontier Airlines
2026-10-25
1 stop
$54
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 San Francisco to Ontario CA get?
The cheapest fare we have tracked on this route is $17, compared with a typical $56 for a trip of this distance.
Is it cheaper to fly to Ontario CA 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 San Francisco to Ontario CA 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.