Cheapest return flights from Phoenix to Denver in September from $71

AirHint found the following cheapest return flights from Phoenix (PHX) to Denver (DEN) in September 2025 (see full year).

Return flights

30 Sep - 30 Sep Frontier Airlines direct
23 Sep - 30 Sep Frontier Airlines direct
25 Sep - 04 Oct Frontier Airlines
24 Sep - 04 Oct Frontier Airlines direct
25 Sep - 04 Oct Frontier Airlines direct
25 Sep - 30 Sep Frontier Airlines direct
23 Sep - 25 Sep Frontier Airlines direct
26 Sep - 30 Sep Frontier Airlines
25 Sep - 27 Sep Frontier Airlines direct
25 Sep - 26 Sep Frontier Airlines direct
26 Sep - 30 Sep Frontier Airlines direct
27 Sep - 27 Sep Frontier Airlines direct
24 Sep - 02 Oct Frontier Airlines direct
25 Sep - 02 Oct Frontier Airlines direct
25 Sep - 29 Sep Frontier Airlines direct
25 Sep - 03 Oct Frontier Airlines direct
24 Sep - 01 Oct United direct

Also check the deals for one-way flights from Phoenix to Denver in September.

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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