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

One-Way flights

29 Sep	Frontier Airlines	direct
23 Sep	Frontier Airlines	direct
25 Sep	Frontier Airlines	direct
30 Sep	Frontier Airlines	direct
27 Sep	Frontier Airlines	direct
26 Sep	Frontier Airlines	direct
20 Sep	Frontier Airlines	direct
21 Sep	Frontier Airlines	direct
18 Sep	Frontier Airlines	direct
19 Sep	Frontier Airlines	direct

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

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.

Book a cheap hotel in Las Vegas

Cheap car rent in Las Vegas

Cheapest one-way flights from Ontario to Las Vegas in September from $36

One-Way flights