AirHint found the following cheapest one-way flights from Ontario (ONT) to San Francisco (SFO) in May 2026 (see full year).
One-Way flights
| 05 May | United | direct | |
| 06 May | United | direct | |
| 01 May | United | direct | |
| 02 May | United | direct | |
| 04 May | United | direct | |
| 03 May | United | direct |
Also check the deals for return 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.
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