The Cottagers agreed a deal for the Greece international in Thursday, as exclusively revealed by Goal, after the striker completed a medical at the west London club’s Motspur Park headquarters.
|10/11||Fulham are 10/11 with Paddy Power to avoid relegation|
Mitroglou joined Olympiakos in 2007 and went on to win three Super League titles, three Greek Cups and one Greek Super Cup during his time with the club.
The 25-year-old has scored 23 goals in 25 matches for club and country this season, including a hat-trick in the Champions League against Anderlecht, making him one of only six players to score a hat-trick in this season's competition.
Mitroglou could prove to be a replacement for Dimitar Berbatov who is set to join Monaco, after travelling to France to complete his transfer to Claudio Ranieri's side.
Goal understands the Cottagers are also hoping to bring in Jonny Heitinga on loan before the close of the window and Manchester United youngster Ryan Tunnicliffe although hopes of signing team-mate Larnell Cole appear to be receding.
Fulham have already confirmed the loan signings of Lewis Holtby from Tottenham and William Kvist from Stuttgart in a busy window for the west Londoners.