Cheapest return flights from Denver to Ljubljana in September from 593€

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

Return flights

27 Sep - 04 Oct Frontier Airlines
11 Sep - 18 Sep Turkish Airlines
18 Sep - 25 Sep Frontier Airlines
28 Sep - 05 Oct Turkish Airlines
16 Sep - 23 Sep Lufthansa
17 Sep - 24 Sep Frontier Airlines
21 Sep - 28 Sep Air Canada
22 Sep - 29 Sep Air Canada
15 Sep - 22 Sep Icelandair
12 Sep - 19 Sep British Airways

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

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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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