The 20-year-old forward has arrived at Celtic Park with a strong reputation, having established himself as one of the best and most promising young players in the Championship during his time at Fulham.
The France Under-20 international will be a key player for Brendan Rodgers’s side during the 2016-17 campaign.
Celtic and Scotland international midfielder Brown has praised Dembele and has outlined how he is going to help the team next season.
SB: "We have brought Moussa in & he has been fantastic. Strong, physical and has an eye for a goal, will definitely help." #UCL (MH)— Celtic Football Club (@celticfc) July 11, 2016
Dembele scored 14 goals and created 42 chances in 42 Championship appearances for Fulham last season.
During the 2014-15 campaign, the young forward created three chances in 11 matches for the Cottagers.
Celtic will be favourites to win the Scottish Premiership title next season, and the Hoops will also be aiming to progress to the group stage of the 2016-17 Champions League campaign.