Giampiero Mazzi (born in Frascati, 14 October 1974) is a former Italian rugby union player and a current coach. He played as scrum-half.
Mazzi played all his career at Rugby Roma Olimpic, becoming a member of the first category in 1994/95. He played there until 2008/09. He won the titles of the Italian Championship, in 1999/2000, and the Cup of Italy in 1997/98. He became coach of the Rugby Roma Olimpic U-20 after finishing his career.
Mazzi had 5 caps for Italy, from 1998 to 1999, scoring 1 try, in an aggregate of 5 points. He was selected for the 1999 Rugby World Cup but never played.