Cheapest one-way flights from Ontario to San Francisco in May from $30

Best time to book flights for Ontario (ONT) to San Francisco (SFO) flights at AirHint

AirHint found the following cheapest one-way flights from Ontario (ONT) to San Francisco (SFO) in May 2025 (see full year).

One-Way flights

08 May Frontier Airlines direct
16 May Frontier Airlines direct
15 May Frontier Airlines direct
05 May Frontier Airlines direct
18 May Frontier Airlines direct
22 May Frontier Airlines direct
13 May Frontier Airlines
24 May Southwest Airlines
17 May Southwest Airlines
09 May Southwest Airlines

Also check the deals for return flights from Ontario to San Francisco in May.

Skyscanner

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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