This is a list of Portuguese winter football transfers for the 2012–13 season.
The winter transfer window opened on 1 January 2013 and closed on 31 January 2013.
Players could be bought before the transfer window opened, but were not permitted to join their new clubs until 1 January.
Additionally, players without a club could join at any time and clubs were able to sign a goalkeeper on an emergency loan if they had no registered goalkeeper available.
Only moves involving Primeira Liga clubs are listed; included are clubs that completed transfers after the end of the summer 2012 transfer window and before the end of the 2012–13 winter window.