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

Return flights

16 Sep - 24 Sep	Air China
19 Sep - 03 Oct	Air France
19 Sep - 01 Oct	Air France
19 Sep - 05 Oct	Air France
19 Sep - 24 Sep	Air France
09 Sep - 17 Sep	Air China
08 Sep - 30 Sep	LOT
08 Sep - 15 Sep	LOT
08 Sep - 16 Sep	LOT
09 Sep - 16 Sep	LOT
24 Sep - 04 Oct	Air France
24 Sep - 01 Oct	Air France
24 Sep - 03 Oct	Air France
24 Sep - 05 Oct	Air France
05 Sep - 12 Sep	China Eastern
24 Sep - 02 Oct	Air France
24 Sep - 23 Oct	Air France
04 Sep - 17 Sep	China Eastern
18 Sep - 23 Sep	Air France
23 Sep - 03 Oct	KLM

Also check the deals for one-way flights from Seoul to Lisbon 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 return flights from Seoul to Lisbon in September from 624€

Return flights