Air Canada and Lufthansa have round-trip flights from Dallas (DFW) to Lisbon (LIS) for $493-$501 with a connection. Flights in September. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
COVID travel restrictions are still in place but this may be worthwhile for the dates later this year.
Read More Cheap Flights: Dallas to Lisbon $493-$501 r/t [September] – Air Canada / Lufthansa