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

Return flights

26 Aug - 05 Sep	Air Canada
10 Aug - 10 Sep	Air Canada
23 Aug - 04 Sep	Icelandair
24 Aug - 12 Sep	Air Canada
24 Aug - 04 Sep	United
25 Aug - 05 Sep	United
20 Aug - 28 Aug	Icelandair
16 Aug - 28 Aug	Icelandair
25 Aug - 03 Sep	SWISS
31 Aug - 08 Sep	SWISS
11 Aug - 25 Sep	Air Canada
18 Aug - 28 Aug	United
11 Aug - 18 Aug	Air Canada
23 Aug - 28 Aug	Icelandair
22 Aug - 28 Aug	Virgin Atlantic
13 Aug - 27 Aug	Delta
11 Aug - 21 Aug	United
13 Aug - 20 Aug	Air Canada
20 Aug - 24 Aug	Icelandair
22 Aug - 02 Sep	Air Canada

Also check the deals for one-way flights from Newark to Lisbon 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.

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Cheapest return flights from Newark to Lisbon in August from 372€

Return flights