Seattle to Ontario CA (SEA → ONT). We are tracking 10 fares on this route.
Cheapest tracked fare $44 · typical price $161 · you save about $117 (73%)
Cheapest fares we're tracking
Airline
Departs
Stops
Price
Frontier Airlines
2026-09-09
Direct
$44
Frontier Airlines
2026-09-10
Direct
$48
Frontier Airlines
2026-10-09
Direct
$49
Frontier Airlines
2026-09-11
Direct
$52
Frontier Airlines
2026-09-14
Direct
$53
Frontier Airlines
2026-09-12
Direct
$54
Frontier Airlines
2026-09-13
Direct
$61
Frontier Airlines
2026-11-08
Direct
$88
Frontier Airlines
2026-09-06
Direct
$91
Frontier Airlines
2026-09-05
Direct
$94
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 Seattle to Ontario CA get?
The cheapest fare we have tracked on this route is $44, compared with a typical $161 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 Seattle 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.