Delta, Virgin Atlantic, Air Europa, Air France and various other airlines have round-trip flights from Seattle (SEA) to Madrid (MAD) for $431-$444 with a connection. Flights February, March, October, and November. Departures on Monday, Tuesday, Wednesday, and Sunday. No Thanksgiving 2023 dates.
A Carry-on bag and also a personal item is allowed for free. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.
Click for more details and booking links Cheap Flights: Seattle to Madrid $421-$444 r/t (No Thanksgiving dates) [Feb-Mar, Oct-Nov] – Delta / Virgin Atlantic / Air Europa / Air France