AirHint found the following cheapest return flights from Washington (IAD) to Porto (OPO) in October 2025 (see full year).

Return flights

21 Oct - 15 Nov	Air Canada
15 Oct - 08 Nov	SWISS
22 Oct - 15 Nov	Air Canada
30 Oct - 06 Nov	Lufthansa
13 Oct - 20 Oct	Lufthansa
18 Oct - 08 Nov	SWISS
24 Oct - 27 Oct	Lufthansa
07 Oct - 14 Oct	Air Canada
01 Oct - 08 Oct	SWISS
11 Oct - 18 Oct	Air Canada
21 Oct - 26 Oct	Turkish Airlines
01 Oct - 09 Oct	Air Canada
08 Oct - 15 Oct	Lufthansa
06 Oct - 20 Oct	TAP
06 Oct - 13 Oct	SWISS
10 Oct - 01 Nov	SWISS

Also check the deals for one-way flights from Washington to Porto in October.

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 Porto

Cheap car rent in Porto

Cheapest return flights from Washington to Porto in October from $473

Return flights