AirHint found the following cheapest one-way flights from Ontario (ONT) to Las Vegas (LAS) in December 2025 (see full year).

One-Way flights

11 Dec	Southwest Airlines	direct
08 Dec	Southwest Airlines	direct
09 Dec	Southwest Airlines	direct
10 Dec	Southwest Airlines	direct
02 Dec	Southwest Airlines	direct
03 Dec	Southwest Airlines	direct
04 Dec	Southwest Airlines	direct
17 Dec	Southwest Airlines	direct
16 Dec	Southwest Airlines	direct
13 Dec	Southwest Airlines	direct

Also check the deals for return flights from Ontario to Las Vegas in December.

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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Cheapest one-way flights from Ontario to Las Vegas in December from $48

One-Way flights