This is a list of Portuguese football transfers for the 2018–19 winter transfer window.
The winter transfer window opened 1 January 2019, although a few transfers may take place prior to that date.
The window closed at midnight on 1 February 2019, although outgoing transfers could have still happened to leagues in which the window is still open.
Only moves involving Primeira Liga clubs are listed.
Additionally, players without a club may join a club at any time.