AirHint found the following cheapest return flights from Porto (OPO) to Oslo (OSL) in September 2025 (see full year).

Return flights

03 Sep - 08 Sep	Norwegian
12 Sep - 15 Sep	easyJet
10 Sep - 14 Sep	Norwegian
18 Sep - 23 Sep	Ryanair
10 Sep - 22 Sep	Norwegian
05 Sep - 08 Sep	easyJet
03 Sep - 22 Sep	Norwegian
03 Sep - 12 Sep	Norwegian
26 Sep - 29 Sep	easyJet
10 Sep - 24 Sep	Norwegian
29 Sep - 06 Oct	Ryanair
26 Sep - 01 Oct	easyJet
10 Sep - 01 Oct	Norwegian	direct
12 Sep - 01 Oct	Norwegian
12 Sep - 01 Oct	Norwegian	direct
26 Sep - 13 Oct	Norwegian	direct
26 Sep - 06 Oct	Norwegian	direct
19 Sep - 06 Oct	Norwegian	direct
29 Sep - 20 Oct	Norwegian	direct
29 Sep - 13 Oct	Norwegian	direct

Also check the deals for one-way flights from Porto to Oslo 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 Porto to Oslo in September from 147€

Return flights