The 24-year-old, who has been the subject of the transfer saga all summer, appears to have finally completed a move to the Nou Camp, according to The Sun.
Barca defender Gerard Pique wrote on his Twitter page: "He's finally here!!"
Meanwhile Carlos Puyol, the captain of the Spanish giants, said: “Welcome home!!! Happy to have you here."
Fabregas is expected to be unveiled at his boyhood club on Saturday and could make his first-team debut for the Primera champions against Real Madrid in the Spanish Super Cup on Sunday.