AirHint found the following cheapest return flights from Lisbon (LIS) to Helsinki (HEL) in August 2025 (see full year).

Return flights

21 Aug - 25 Aug	Ryanair
21 Aug - 28 Aug	Ryanair
31 Aug - 07 Sep	Ryanair
19 Aug - 26 Aug	Ryanair
27 Aug - 30 Aug	Ryanair
21 Aug - 24 Aug	Ryanair
10 Aug - 28 Aug	Ryanair
04 Aug - 11 Aug	Ryanair
20 Aug - 28 Aug	Ryanair
06 Aug - 20 Aug	Ryanair
04 Aug - 14 Aug	Ryanair
29 Aug - 07 Sep	easyJet
29 Aug - 07 Sep	Finnair	direct
01 Aug - 12 Sep	Ryanair
01 Aug - 12 Sep	Finnair	direct

Also check the deals for one-way flights from Lisbon to Helsinki in August.

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.

Book a cheap hotel in Helsinki

Cheap car rent in Helsinki

Cheapest return flights from Lisbon to Helsinki in August from $274

Return flights