Cheapest return flights from San Francisco to Ontario in May from 48€

AirHint found the following cheapest return flights from San Francisco (SFO) to Ontario (ONT) in May 2026 (see full year).

Return flights

28 May - 30 May Frontier Airlines direct
26 May - 28 May Frontier Airlines direct
09 May - 11 May Frontier Airlines
04 May - 07 May Frontier Airlines
28 May - 31 May Frontier Airlines direct
11 May - 15 May Frontier Airlines direct
07 May - 10 May Frontier Airlines direct
29 May - 01 Jun Frontier Airlines direct
18 May - 18 May Frontier Airlines direct
21 May - 25 May Frontier Airlines direct
15 May - 18 May Frontier Airlines direct
30 May - 03 Jun Southwest Airlines
30 May - 01 Jun Southwest Airlines
29 May - 02 Jun Southwest Airlines

Also check the deals for one-way flights from San Francisco to Ontario in May.

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