Cheapest return flights from Ontario to San Francisco in May from $486
AirHint found the following cheapest return flights from Ontario (ONT) to San Francisco (SFO) in May 2025 (see full year).
Return flights
| 29 May - 01 Jun | Alaska Airlines | ||
| 05 May - 17 May | Alaska Airlines |
Also check the deals for one-way flights from Ontario to San Francisco in May.
The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.
