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

Return flights

23 Sep - 13 Oct	Ryanair
23 Sep - 14 Oct	Ryanair
24 Sep - 01 Oct	Ryanair
23 Sep - 11 Oct	Ryanair
23 Sep - 27 Sep	Ryanair
23 Sep - 12 Oct	Ryanair
13 Sep - 15 Sep	Ryanair
13 Sep - 16 Sep	Ryanair
26 Sep - 29 Sep	Ryanair
25 Sep - 01 Oct	Ryanair
26 Sep - 04 Oct	Ryanair
12 Sep - 15 Sep	Ryanair
13 Sep - 19 Sep	Ryanair
04 Sep - 12 Sep	Norwegian Air Sweden AOC
23 Sep - 15 Oct	Ryanair
23 Sep - 28 Sep	Ryanair
25 Sep - 28 Sep	Ryanair
16 Sep - 23 Sep	Ryanair
29 Sep - 05 Oct	Ryanair
22 Sep - 10 Oct	Ryanair

Also check the deals for one-way flights from Lisbon to Riga 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 Lisbon to Riga in September from 171€

Return flights