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

Return flights

03 Dec - 07 Dec	Air Canada
06 Dec - 13 Dec	Finnair
01 Dec - 10 Dec	Alaska Airlines
10 Dec - 17 Dec	Alaska Airlines
17 Dec - 27 Jan	Alaska Airlines
16 Dec - 20 Dec	British Airways
20 Dec - 29 Jan	Alaska Airlines
19 Dec - 26 Jan	British Airways

Also check the deals for one-way flights from Ontario 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.

Book a cheap hotel in Lisbon

Cheap car rent in Lisbon

Cheapest return flights from Ontario to Lisbon in December from $676

Return flights