Ontario CA to Denver (ONT → DEN). We are tracking 10 fares on this route.
Cheapest tracked fare $31 · typical price $128 · you save about $97 (76%)
Cheapest fares we're tracking
Airline
Departs
Stops
Price
—
2026-11-06
Direct
$31
—
2026-11-12
Direct
$35
—
2026-11-10
Direct
$36
Frontier Airlines
2026-12-31
Direct
$37
—
2026-11-23
Direct
$42
Frontier Airlines
2027-01-01
Direct
$46
—
2026-12-10
Direct
$57
Frontier Airlines
2026-12-20
Direct
$67
Frontier Airlines
2026-11-22
Direct
$69
Frontier Airlines
2026-11-21
Direct
$70
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 Denver get?
The cheapest fare we have tracked on this route is $31, compared with a typical $128 for a trip of this distance.
Is it cheaper to fly to Denver 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 Denver 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.