Cheapest return flights from Denver to Lisbon in September from $532

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

Return flights

08 Sep - 16 Sep Aer Lingus
27 Sep - 04 Oct Icelandair
22 Sep - 29 Sep Air Canada
20 Sep - 28 Sep Icelandair
30 Sep - 07 Oct Lufthansa
18 Sep - 23 Sep Air Canada
30 Sep - 05 Oct Icelandair
21 Sep - 28 Sep Frontier Airlines
13 Sep - 22 Sep United

Also check the deals for one-way flights from Denver to Lisbon 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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