AirHint found the following cheapest one-way flights from Houston (IAH) to Denver (DEN) in September 2025 (see full year).

One-Way flights

23 Sep	Frontier Airlines	direct
21 Sep	Frontier Airlines	direct
20 Sep	Frontier Airlines	direct
22 Sep	Frontier Airlines	direct
27 Sep	Frontier Airlines	direct
06 Sep	Frontier Airlines	direct
14 Sep	Frontier Airlines	direct
15 Sep	Frontier Airlines	direct
12 Sep	Frontier Airlines	direct
24 Sep	Frontier Airlines	direct

Also check the deals for return flights from Houston to Denver 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.

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Cheapest one-way flights from Houston to Denver in September from $18

One-Way flights