Feruz has just turned 16-years-old but turned down the offer of a first professional contract with Scottish giants Celtic in favour of a move to the Premier League.
Manchester United and Manchester City were both reportedly interested in the highly-rated Scotland Under-17 international but Chelsea made an "extraordinary impression" on Feruz.
"He is looking forward to starting his career with Chelsea, but he would love to thank Celtic for all they did for him and his parents, he is Scottish and will one day score goals for Scotland," agent Rui Alves told Sky Sports.
"It is a massive step for Islam and for Scottish football," Alves added. "Now for him personally it is the beginning of a major adventure, he will have to work, work and work and raise his own level.
"Playing for a top club like Chelsea, where the major word in the squad is quality, will oblige him to show his own quality and deliver his best and convince the staff that he is more than just a major prospect."
Alves confirmed that Chelsea had fended off interest from around Europe to sign Feruz.
"It was not just every club in the Premiership but also most big clubs in Europe who were tracking him. He is the one serious player in Scotland at the moment."
