AirHint found the following cheapest one-way flights from Washington (IAD) to Lisbon (LIS) in October 2025 (see full year).

One-Way flights

23 Oct	Icelandair
09 Oct	Icelandair
30 Oct	Icelandair
11 Oct	Frontier Airlines
06 Oct	Air Canada
10 Oct	Porter Airlines (Canada) Ltd
03 Oct	Porter Airlines (Canada) Ltd
04 Oct	Porter Airlines (Canada) Ltd
02 Oct	Icelandair
14 Oct	TAP	direct

Also check the deals for return flights from Washington to Lisbon 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.

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Cheapest one-way flights from Washington to Lisbon in October from $253

One-Way flights