Cheapest return flights from Seattle to Ljubljana in September from $644

Best time to book flights for Seattle (SEA) to Ljubljana (LJU) flights at AirHint

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

Return flights

24 Sep - 01 Oct KLM
16 Sep - 23 Sep KLM
30 Sep - 07 Oct KLM
23 Sep - 30 Sep Air France
25 Sep - 02 Oct KLM
22 Sep - 29 Sep Lufthansa
29 Sep - 06 Oct Lufthansa
04 Sep - 11 Sep Delta
01 Sep - 08 Sep SWISS
18 Sep - 27 Sep Turkish Airlines

Also check the deals for one-way flights from Seattle 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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