Cottagers boss Martin Jol has previously managed the player at Ajax, where he came through the youth system, and had spoken of the deal after Wednesday's 3-1 victory over West Ham, saying: "He can play left midfield, wide, play number 10. I feel we need fresh legs. He is a skilful player, very agile. He is very mobile and quick."
Emanuelson signed for Milan in January 2011 and has made 60 appearances for the club, but the 26-year-old has found himself sidelined this season.
The deal is one of several Fulham have been rumoured to be involved with, with a move for Tottenham's Tom Huddlestone also looking possible. He is the second signing of the window so far for Fulham, with Arsenal's Emmanuel Frimpong already having joined on loan.