Matteo Manassero began playing golf at the age of 3 and a half at the Villafranca Golf Club. In 1998 he moved to the Gardagolf Country Club of Soiano del Lago (BS) coached by Franco Maestroni; one of the first to notice him and talk about him is the television journalist Germano Mosconi, who became known in the Internet world in the 2000s for his off-air broadcasts while hosting the information programs of the local Telenuovo broadcaster. He currently trains and lives at the Monticello Golf Club (near Como) and is followed by Alberto Binaghi.
In 2009, at the age of 16, he won the British Amateur Championship, one of the two Majors for amateurs. With this victory Matteo establishes the record of youngest winner of the tournament and first Italian, guaranteeing himself the invitation to two Majors: the Open Championship and The Masters.
During the 2009 Open Championship in Turnberry, Matteo finished in 13th place, tied with Francesco Molinari, earning the Silver Medal: the prize awarded to the best amateur in the competition.
On May 26, 2013 he won the prestigious BMW PGA Championship on the Wentworth Club course after a four-hole playoff against Simon Kahn and Marc Warren, thus becoming the youngest winner in the history of the tournament and reaching 25th place in the world order of merit.
At the beginning of January 2014, he changed technical sponsor from Titleist to Callaway.