William Pianu (born 7 December 1975) is an Italian football coach and a former defender.
Pianu started his career at Juventus. He spent 7 seasons at Treviso.
After the bankrupt of Treviso, he was signed by Gallipoli along with team-mate Alessandro Moro in August 2009. He left in summer 2010 his club U.S. Pergocrema 1932 to sign for Venezia.