Cheapest one-way flights from Washington to Lisbon in September from $274

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

One-Way flights

02 Sep Icelandair
01 Sep Icelandair
30 Sep Icelandair
13 Sep Frontier Airlines
12 Sep Porter Airlines (Canada) Ltd
05 Sep Frontier Airlines
04 Sep Icelandair
17 Sep Icelandair
27 Sep Frontier Airlines
06 Sep Icelandair

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

Skyscanner

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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