AirHint found the following cheapest return flights from Houston (IAH) to Lisbon (LIS) in December 2025 (see full year).

Return flights

03 Dec - 10 Dec	Air Canada
12 Dec - 25 Dec	Air Canada
30 Dec - 06 Jan	United
29 Dec - 05 Jan	British Airways
24 Dec - 31 Dec	Air Canada
23 Dec - 30 Dec	Air Canada
25 Dec - 01 Jan	British Airways
22 Dec - 29 Dec	Air Canada
28 Dec - 04 Jan	British Airways
21 Dec - 28 Dec	Air Canada
27 Dec - 03 Jan	British Airways
20 Dec - 27 Dec	British Airways
19 Dec - 26 Dec	Virgin Atlantic
26 Dec - 02 Jan	British Airways
18 Dec - 03 Jan	Air Canada

Also check the deals for one-way flights from Houston to Lisbon in December.

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 Houston to Lisbon in December from $596

Return flights