Detour Flights

Cheap flights to Ontario CA

We are tracking 198 fares into Ontario CA (ONT) from 42 departure airports.

Cheapest tracked fare $17  ·  about $39 below the typical price for that distance

Cheapest fares we're tracking

FromDepartsStopsPrice
(SFO)2026-12-12Direct$17
San Francisco (SFO)2026-12-08Direct$19
(SFO)2026-12-01Direct$20
San Francisco (SFO)2026-11-16Direct$22
San Francisco (SFO)2026-11-12Direct$24
San Francisco (SFO)2026-11-09Direct$24
San Francisco (SFO)2026-10-22Direct$24
(SFO)2026-12-07Direct$26
San Francisco (SFO)2026-11-13Direct$28
San Francisco (SFO)2026-10-23Direct$30
San Francisco (SFO)2026-10-19Direct$30
San Francisco (SFO)2026-10-29Direct$31
(DEN)2026-11-26Direct$31
(DEN)2026-11-10Direct$32
(DEN)2026-11-17Direct$33
San Francisco (SFO)2026-12-04Direct$33
San Francisco (SFO)2026-12-06Direct$33
San Francisco (SFO)2026-12-11Direct$33
Denver (DEN)2026-11-03Direct$33
(SEA)2026-12-07Direct$34

Popular departure airports

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Compare every airport, not just this one

Pin one end of your trip and let a whole region compete for the other. The cheapest airport is often not the one you were going to use.

Find my cheapest airport

Common questions

Which airports have cheap flights to Ontario CA?
We are currently tracking 198 fares into Ontario CA from 42 departure airports, listed cheapest first above.
Is Ontario CA the cheapest airport for this trip?
Not always. Cached fare feeds cover big hubs densely and secondary airports sparsely, so a cheaper nearby airport is often simply missing from a normal search rather than more expensive. Our reverse search prices a whole region's airports against each other to surface it.