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

Return flights

05 Aug - 14 Aug	Delta
14 Aug - 21 Aug	Iberia
19 Aug - 26 Aug	United
13 Aug - 20 Aug	United
20 Aug - 31 Aug	Delta
05 Aug - 12 Aug	United
15 Aug - 22 Aug	United
23 Aug - 30 Aug	United
21 Aug - 28 Aug	United
27 Aug - 03 Sep	United
11 Aug - 18 Aug	United
25 Aug - 01 Sep	United
29 Aug - 05 Sep	United
31 Aug - 07 Sep	United

Also check the deals for one-way flights from Austin 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 Austin to Lisbon in August from $808

Return flights